TRIUMF: Canada's national laboratory for particle and nuclear physics

Experimental facilities at TRIUMF Pearce, Robert Michael Aug 31, 1975

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata


51833-TRI-1975-02.pdf [ 20.7MB ]
JSON: 51833-1.0107812.json
JSON-LD: 51833-1.0107812-ld.json
RDF/XML (Pretty): 51833-1.0107812-rdf.xml
RDF/JSON: 51833-1.0107812-rdf.json
Turtle: 51833-1.0107812-turtle.txt
N-Triples: 51833-1.0107812-rdf-ntriples.txt
Original Record: 51833-1.0107812-source.json
Full Text

Full Text

T R I U M FExperimental Facilities at TRIEdited by R.M. PearceTRIUMFPhysics Department University of VictoriaMESON FACILITY OF:UNIVERSITY OF ALBERTA SIMON FRASER UNIVERSITY UNIVERSITY OF VICTORIA UNIVERSITY OF BRITISH COLUMBIATRI-75-2AugustExperimental Facilities at TRIUMFEdited by R.M. PearceTRIUMFPhysics Department University of VictoriaMESON FACILITY OF:UNIVERSITY OF ALBERTA SIMON FRASER UNIVERSITY UNIVERSITY OF VICTORIA UNIVERSITY OF BRITISH COLUMBIA]. 2 .3 -b.5 .6 3 7- 8 39- 51. 55 .52313-lb.15-16.17.18. 19-. 2 0 .  25 . 223 23 - 2b. 25 -Polarized H" ion sourceUnpolarized H" ion sourceInjection beam lineCyclotron support st ructureCyclotron magnet sectorBeam line IVBeam 1i ne IVbProton target with scattering standProton spectrometer100 nA beam dumpF1 in. scattering chamberSuperconduct i ng solenoi dLiquid deuterium ta rgetBeam 1i ne IVaTime-of-f1ight mass i dent i f i cat ion fac i5i ty10 pA beam dumpFertile to fissile conversion studiesNeutron collimatorSpin precession magnetBeam 1i ne IPion spectrographMeson target T2Stopped E E x p  channelMSR channelMedical channelCONTENTS1. INTRODUCTION .....................................................  i2. THE C Y C L O T R O N ................................................... i235 Acceleration of H “ I o n s ..................................... i232 Radio Frequency................................................  g2.3 Proton Beams ................................................  g2.A Proton Beamline Monitors (D.A. Bryman) ..................  .3- THE PROTON EXPERIMENTAL A R E A ....................................3.1 Beam Line IVa (G.M. Stinson) ................................. .3-2 Beam Line IVb (G.M. Stinson) ................................ 103-3 First Target on Beam Line IVb (J.G. R o g e r s ) ................ 113-4 Proton Spectrometer (G.M. Stinson, P. Kitching) .......... 123-5 Polarized Proton Beams (G. R o y ) ............................5n3-6 Liquid H2/D2 Target (T.A. Hodges) ..........................  5n3.7 Neutron Beams (L.P. Robertson) ............................  5g3-8 Scattering Chamber (R. Green) ..............................  5.3-9 A Gas Jet - Mass Identification Facility (J.M. d'Auria) . 203.10 Fertile to Fissile Conversion (B.D. Pate)  ...............  21A. THE MESON A R E A .....................................................21A. 5 G e n e r a l ......................................................... 25A.2 Beam Line I Tunnel ........................................... 22A.3 The Meson Production T a r g e t s ............................... 22A.A The Target Shield for T2 .................................... 2iA.5 The Proton Beam L i n e .........................................26A 3 F The High Resolution Pion Channel at T1 (L.P. Robertson) . 26A. 7 The Stopped tt/p C h a n n e l ........... . ........................ i1A 3 o The Biomedical Pion Channel (L.D. Skarsgard) ...........  3AA 3 . Thermal Neutron Facility ..................................  iFA,10 The MSR Facility (J.H. Brewer) ....................   iF5. INSTRUMENTATION POOL (G. Jones)...................................ioRE FE RE NC ES............................................................ ..- 2 -- i -] .  I NT RODUCT I ONTRIUMF is a sector-focused cyclotron for 525 MeV protons, constructed on the University of British Columbia campus in Vancouver by the University of Alberta, Simon Fraser University, the University of Victoria and the University of British Columbia with funds provided by these universities and the Atomic Energy Control Board of Canada. The first external beam was extracted late in 197^• At the time of writing, the beam current is being increased while machine development and the installation of shield­ing take place. The ultimate desian current is 100 yA.This report summarizes the properties of the beams, channels and spectro­meters which are installed or in an advanced stage of planning. Full accounts of the present status of the cyclotron will appear in the Pro­ceedings of the VII International Cyclotron Conference, Zurich (1975).In Section 2 there is a brief discussion of those features of the cyclo­tron which make the beams at TRIUMF unique. The most important of these features is the acceleration of H ions. Section 3 describes the Proton Area, which is the experimental area to the west of the cyclotron, and Section A describes the Meson Area, which is to the east (cf. Fig. 1).2. THE CYCLOTRON2.1 Acceleration of H IonsThe TRIUMF concept (Richardson, 19&3) features acceleration of H ions. The extraction of proton beams from the cyclotron is effected by strip­ping two electrons from the H“ ion by inserting - or partially insert­ing - foils into the H~ beam inside the cyclotron. By varying the radial position of the stripper foils in the cyclotron, proton beams have been obtained at TRIUMF in the energy range 180 to 520 MeV. The advantage of this concept lies in obtaininq simultaneous proton beams of good resolution and of independently variable energy. Two beams were brought out in . (in principle, beams could be brought out between each of the six return yokes, but the presence of the reson­ators interferes with some potential extraction positions and the number of beams which can be extracted is probably limited to four. Space has been left for expansion of the building north and south.)-  b -fi f/ \T->^A 60 in. scattering chamber B Super-conducting solenoid C Time-of-f1ight mass i dent i f icat ion fac i5i ty D Neutron collimator E 10 pA beam dump F Proton target with scattering stand (PTl)G Proton spectrometer H 100 nA beam dump I Meson target (T2)J Stopped Tr/p channel K MSR fac i1i ty L Medical channel M TINA and tt production exper i ments N BASQUE experimentsN-  n -Fig. 1- F -The stripping foils are mounted on probe arms that move above the beam plane, and the foils are lowered into the beam at the radius corresponding to the desired energy. Beams of all energies must somehow reach a common external point, and this is accomplished by having the stripper foil follow a certain complicated path as the energy is changed (Tautz and Robertson, 1970). The first beamline element is called the "combination magnet"; it is located at the common point and steers the beam down the external beam line. It is required that the system from the stripper foil to the first target be achromatic. The first element of the extraction system is the cyclotron field itself, and this has a fixed dispersion. Accordingly the bending magnets in the extraction beam line are set so as to cancel the dispersion of the cyclotron field.The stripper for the beam which has the lower energy is only part­ially inserted into the H beam, whereas the high energy stripper at the larger radius must completely intercept the remaining beam in order that the beam not activate the cyclotron.The use of the H ion places limits on the maximum current which can be accelerated. The cyclotron magnetic field must be relatively weak to stop excessive stripping of the second electron on the H~ ion, which is only weakly bound (Stinson, 1969). As a result, the cyclotron magnet is unusually large. The final magnet design dia­meter of 57 ft resulted from choosing the following criterion: the activation of the machine by neutral hydrogen from electric and residual gas stripping of H should not make servicing impossible after shutdown from 100 yA operation. (However, the electric strip­ping occurs predominantly at the maximum energy and it may be that operation at a few hundred microamperes is possible with H" energy reduced to 450 MeV.)The design current of 100 pA may also be close to the limit of performance of the thin stripping foils, which must be radiation cooled. Unfortunately, the two stripped electrons spiral in the magnetic field, giving up all their energy (250 keV/electron for 500 MeV ions) in repeated passages through the foil.- g -2.2 Radio FrequencyThe feature which interests us here is that the resonators are quarter wave stubs with the open end on the dee-gap. This makes possible the addition of a third harmonic (31/4 in the same resonator) to flatten the RF waveform. This should greatly ease some problems (Dutto, 1972) in obtaining large phase acceptance and good energy resolution. Third harmonic operation is planned for 5.gF .The accelerating dees are unusual in that they are also the resonators.This is made possible by the large size of the vacuum tank and by choosing the RF frequency to be 23.075 MHz, which is a factor five times the orbit frequency.2. 3 Proton BeamsBeams of independently variable energy have been simultaneously ex­tracted into beam line I and beam line IV in 1975- When tune-up of the cyclotron is completed the raw proton beam from a wide (i.e. greater than the separation of the centers of two consecutive orbit separations) stripper is expected to have a full width of ± F11 keV.This resolution is based on the estimated emittance at 500 MeV whichis 532 tt mm mrad axially and radially.Since the cyclotron is isochronous, the macroscopic duty cycle is 100%. The beam characteristics have been discussed by Richardson (1969), Richardson and Craddock (I.F. ), and Dutto et at. (1972).The microscopic duty cycle will be approximately 13%» or 5 nsec every 43 nsec, without the third harmonic in the RF. But it is planned to operate as soon as possible with the third harmonic, and in this case the microscopic duty cycle will be increased to 20%, or 9 nsec every 43 nsec. This information is summarized in the first line of Table 2.3.- o -Table 2.3Summary of the Main Characteristics at 500 MeV for the Tuned-up Extracted Proton BeamsMode of Operat i onFul1 Width Energy Spread (keV)PhaseAcceptanceEst i mated I ntens i ty (yA)M i croscop i c Duty Factor (*)Raw Beam ± 600± 23°± 35°(3rd)5111001320Low Energy Slits 131i2 in.± 511± 1 .8 °± 5b°(i rd)58Sepa rated TurnAcce1erat i on± 50 ± 25± 0.5°± F .g° (i rd)5300.33-7(3rd) indicates that the proper mixture of third harmonic of the RF voltage is used.Two methods of improving the energy resolution are planned. These are made possible by the use of H ions (cf. § 2.1). In the method called "low energy slits", two pairs of slits (i.e., stripping foils) are used at about 15 MeV to reduce the amplitude of the radial oscil­lation of the beam envelope, and incidentally the intensity. The method in the table called "Separated Turn Acceleration" would nor­mally entail severe tolerances on the magnetic field and resonator voltage. However, the use of the third harmonic RF (cf. § 2.2) greatly relaxes these tolerances. Separated orbit operation promises the best resolution, 90 keV at 500 MeV, and has the advantage that it could be used with the polarized ion source.Both methods of improving the resolution are being carried forward and a choice will be made between them after some operating experience.- . -2.A Proton Beamline MonitorsSeveral types of monitors are used for external proton beam measure­ments. The most widely used device is the multiwire chamber (MWC) which provides horizontal and vertical beam profiles of 5 mm, 3 mm or 5 mm resolution. For low beam currents (£ 500 nA), gas-filled, sealed ionization chambers (MWIC) are used, and at high currents (^ , 500 nA) secondary emission chambers (MWSEM) are used. The charge collected by each wire of an MWC is integrated individually for a fixed interval and then a complete chamber scan is read out to an oscilloscope. Further information on beam shapes can be obtained with scintillation screens viewed by TV cameras.Total current and beam centering information comes from split plate secondary emission monitors (SPSEM) . These devices consist of five thin A1 foils, the second and fourth of which are split along the vertical and horizontal beam centers, respectively, and collect secondary electrons emitted by the other foils when the beam passes through the chamber. They are operable over the entire beam current range. The difference currents (left-right and down-up) are minim­ized to center the beam and the sum of all four currents is propor­tional to the beam intensity.3. THE PROTON EXPERIMENTAL AREAAs indicated in Fig. 1, the proton experimental area lies to the west of the cyclotron vault. It is in this area that the primary proton beam will be utilized in nuclear physics and nuclear chemistry experi­ments. The proposed experiments can be roughly divided into two groups - those requiring high beam currents (£ 10 pA of 500 MeV protons) and those requiring low beam currents (a, 100 nA of 500 MeV protons).3.1 Beam Line IVaThe high intensity line, designated beam line IVa, enters the north­east corner of the area, passes through two experimental locations, and is then deflected so as to exit from the area in the north-west corner, passing through two possible experimental locations along its path. The beam is dumped in a beam dump external to the building.- 51 -The first target location outside the vault on beam line IVa is a large (F1 " <J>) scattering chamber (§ i -o) which will be used in fission and spallation experiments. At the next experimental lo­cation is a liquid deuterium target cell (§ i -F ) to be used in the measurement of various neutron and proton scattering parameters. These will use both unpolarized and polarized primary beams and, for the latter, a superconducting solenoid is installed between the two targets in order to provide spin-flip of the incident beam.A neutron collimator follows the LD2 target and is used to select an appropriate beam to strike a liquid hydroaen target.Following the LD2 target the primary beam is bent towards the north­west corner of the experimental area. Near the point of exit, an irradiation cell (§ 3-9) is positioned. Nuclear fragments recoiling out of a target foil are swept away in a continuous gas flow and taken elsewhere for analysis. Mid-way between this target and the preceding bending magnet, allowance has been made for the insertion of a total neutron cross section experiment. It is planned to stop the beam in this facility when such measurements are being made.Beam line IVa has a 10 cm diameter beam tube to the exit of the irradiation cell. From that point to the point of exit from the experimental area, a 20 cm diameter beam tube is used. Both the scattering chamber and LD2 target can operate simultaneously. It may even be possible to operate the irradiation cell at the same t i m e .3. 2 Beam Line IVbBy powering another dipole in the cyclotron vault, extracted beam can be sent down beam line IVb, the low intensity line. This line cuts almost diagonally across the proton experimental hall and beam is dumped in an internal 100 nA dump. Two experimental locations are placed on this line.- 5 5 -Beam line IVb has been designed to be run in either a dispersed or an achromatic mode. Operation in the dispersed mode will be pri­marily used for beam diagnostic work. When running dispersed, a horizontal magnification of 0.75 and a dispersion of 12.5 cm/% can be attained at the first target location on the beam line. This allows determination of the energy spread in the extracted beam.In addition the line can be run achromatically in a double spatial or double angular focus mode. This mode of operation can allow determination of the beam size and divergence at the stripper foil. Thus all phase space characteristics of the extracted beam can, in principle, be determined.For experimental use, however, beam line IVb will be normally run in an achromatic mode with a double waist at the first target position (§ 3-3). Since experiments proposed for this location are of the elastic and quasi-e5astic scattering varieties, good angular resolution is required and, in the double waist mode, beam divergence on target is 4 ± 2 mr. Both solid and liquid (i He) targets will be used.The second target location will be that of the proton high reso­lution spectrometer (§ i -i )-Up to a point approximately A m past the first target location on this line all quadrupoles and beam tubes are 10 cm diameter. Beyond that point, because of the multiple scattering in the target, 21 cm diameter beam tube and quadrupoles are required. In general, opera­tion of either target on this line precludes operation of the other.3•3 First Target on Beam Line IVbAt the PT1 position on beam line IVb (Fig. 1) is located a general purpose scattering stand suitable for a variety of proton scattering experiments. The scattering stand consists of a circular table 1.28 m in diameter. On the table is mounted a rectangular vacuum box which can accommodate a variety of target changing mechanisms. Thin windows allow charged particles to emerge from the box into air at angles in the range 1 = ig °“ 512° and 1 = 1A6°-170°. A special extension can be- 52 -attached downstream of the box to allow charqed particles to emerge at small angles to the beam (9 = 3°~13°). The beam enters and exits in a 4" diameter vacuum pipe w h i c h  is coupled to the box on either end.Around the central table is a circular track on which roll four mov­able booms to carry the detection apparatus. Each boom can be re­motely positioned at one degree intervals anywhere in the horizontal plane. The angles are digitally encoded and presented to the acqui­sition computer via a CAMAC interface module. The booms have been used to carry detector telescopes designed for observing proton el­astic scattering, various quas i-el as t i c reactions, and ep rEEi reac­tions. Detectors can conveniently be mounted on the booms at dis­tances from 13F m to i-1  m from the target.3 .h Proton SpectrometerThe high resolution spectrometer (Stinson and Reeve, 1972; Stinson and Kitching, 1972) is designed for particles with Bp = 36.36 kG-m; viz. 500 MeV protons, 295 MeV deuterons, 205 MeV tritons, etc. The final version of the spectrometer will be in a vertical quadrupole- dipole-dipole system similar to that of LAMPF. A major factor in the choice of a vertical system was the conservation of floor space. The spectrometer bottom frame and the ^ 10 m radius track on which it rotates are now in place. A schematic elevation is shown in Fig.3.^. The auadrupole preceding the bending magnets provides an in­termediate focus in the non-bend (y) plane between the two dipoles. By providing this intermediate image, the quadrupole also makes possible a larger non-bend plane angular acceptance and the use of smaller magnet gaps. Dipole edges are wedged to provide the additional requirements at the detector of a point-to-point imaging em x n t = 1) in the bend plane and para 55 el-to-point imaging (y/y =0) in the non-bend plane. Table }.h compares the spectrometer specifications with those of LAMPF.Fig. 3.A- 5s -Unfortunately, funds to commission the complete spectrometer have not been available. For the initial experiments in 1976 the quad- rupole and first dipole will be used as a medium resolution spec­trometer (Kitching and Stinson, 1972). The first dipole and power supply are currently being commissioned.Table 3-4Comparison of the Specifications of LAMPF and TRIUMF SpectrometersPa ramete rTotal Bend AngleMean Radius of Curvature (m)So 1 i d Ang 1 e (ms r)Momentum ResolutionAngular Resolution (mr)LAMPF150°3-53.6^±1 .15% for ±2 .n% incident momentum spread0 . 8Incident Proton Energy Range (MeV) 300-800Incident Beam O.uality (MeV)Dispersion (cm/%)Angular Range800 ± 3 - 55o32 2 .5°-51° 3) 51 - 5g1ot+)TRIUMF521 °2.53-5-±1 .15% for ±2.5% incident momentum spread^ 2200-500500 ± 0.51)n11 ± 1 .I2)523o51° - 5g1°5)4.5°- 570°5)1) Initial beam2) Ultimate beam3) Internal beam stop**) Fu 1 1 beam5) Full beam standard quadrupole °) Full beam "septum-quadrupole"- 5n -3.5 Polarized Proton BeamsH” beams with approximately 100 nA intensity and polarization ex­ceeding gn% with the same emittance and duty cycle as the unpolar­ized beam will be injected in the fall of -The polarized beam is being commissioned as soon as possible since it is compatible with the minimum shielding which will be available in the early stages of operation. The TRIUMF polarized ion source which has been built and tested at the University of Alberta is of the Lamb-shift type, using the fast zero-crossing technique (sona method) for the sake of simplicity. A high powered duoplasmatron furnishes the primary beam. Spin reversal is accomplished by re­versing the fields inside the source itself in order to eliminate beam focusinq effects. The entire source is enclosed in a Faraday cage held at i11p111 volts, to yield the injection energy required for TRIUMF.Some degree of spin precession will be necessary in order to correct for that precession caused by the fringing fields of the cyclotron. This will be accomplished by a Wien filter operating on the 300 keV beam. Also the beam will be tailored to give the desired pulse lengths by a chopper-buncher system, again operating on the 300 keV beam.Polarized protons may also be produced by scattering the unpolarized primary beam from a liquid hydrogen target at 5n°; this produces a beam polarization of 51% at 500 MeV (Robertson, 1970).3.6 Liquid H2/D2 TargetThis target, which is shown in Fig. 3-6 (Hodges, 1973), is a produc­tion target located in beam line IVa (cf. Fig. 1) for neutrons from the D(p,n)2p reaction at 0°, for polarized protons from p(p,p^) near 15°, and polarized neutrons from D(p,^)2p near 27° or D(p,n)2p near 51*.f3ONE FOOT|----------- 5 Flq. i3F  Mechanical Layout of Complete Tarpet Structu- 5g -A set of three target thicknesses and a no-target position will be remotely selectable by the experimenter. The targets are fabricated with an all-welded construction from thin (1 .115" at beam entry and exit) stainless steel. To prevent boiling or large density changes in the liquid along the beam path, the liquid is cooled 'v i ° below its boiling point and circulated round the target-cooler loop by a small fan. The beam spot on target is 0.4 cm x 1.0 cm; maximum dissipation is 100 watts. The large cryogenic capacity (from the standby Philips B20 cryogenerator for cyclotron vacuum system) allows fast cooling and condensing at start-up. Cooldown is aided by circulation fan running in the gaseous H2/D2 . The estimated startup time is F hours.The total H2/D2 inventory is 4.0 liquid litres, of which *v 50% is liquid in the target during operation. The system is always above atmospheric pressure to insure against air in-leaks.3.7 Neutron BeamsA neutron beam from the reaction D+p -* 2p+n, essentially monoener- getic and variable in energy (Measday, 5.FF ), will be produced by bombarding the liquid deuterium target.The reaction at 0° is characterized by a high energy peak which has a theoretical width of 1.2 MeV at 150 MeV. Approximately 85% of the neutrons are within 10 MeV of the maximum energy. The yields expected for an incident beam of 10 uA are shown in Table 3 - 7 - 1•- 5o -Table 3-7.)Unpolarized Neutron BeamsReaction: D(p,n) 2p @ 0°Target: LD2 (5 MeV energy loss) Proton beam intensity: 10 pA Neutron beam characteristicsEp 211 n11 MeVFn 197 497 MeVAEn(FWHH) % F F MeVTarget length 5 51 cmYield i nto ±1 .i ° 13F 531 51o n/secFlux at o meters 0.7 532 51F n/secIt is seen that yields of the order of 10o neutrons into a 1° cone are expected.Polarized neutrons are produced in the same D(p,n)2p reaction at an angle of 27° with polarization of 34%; however, the energy peak is significantly broader at this angle. An estimate by Measday suggests the peak may be as much as 40 MeV wide at 500 MeV.Polarized neutron beams can also be produced using the polarized proton beam and the liquid deuterium target in the reaction D(p,n)2p. The polarization transfer is expected (Robertson, 1970) to be 25% at 1°, giving a neutron yield of 23n x 51o n/sec into a 5° cone with polarization 20%. At a production angle of o°, using the rotation transfer parameter, a polarized beam of 53o x 51F n/sec can be pro­duced with polarization of 75%- Although the intensity is two orders of magnitude lower than polarized neutron beams produced from unpolarized proton beams, the energy width of the peak is an order of magnitude better. The polarized beams available from TRIUMF are summarized in Table 3.7-2.- 19 - Table 3-7-2Polarized Beams Available from a Pola rized Ion SourceYield p/secF l 51w(emi ttance 5 .ntt mm mrad)2.5 x 51F into ±1 .n°5 3o x 51ninto ±1 .n°3 3o Scattering ChamberA thin-target scattering chamber at TRIUMF is installed in beam line IVa as shown in Fiq. 1. The chamber has 0.1° accuracy.The 60" inside diameter should allow most fragment emission studies to be done inside the chamber where remote positioning of the solid- state detectors allows all anqles to be studied with one set-up.The large diameter allows for rudimentary time-of-f1ight to be done inside the chamber as an aid in identifying the fragments. For accurate time-of-f5ight studies using extension arms, F" bore access ports are available at 5F angles between the beam entrance and exit ports. The scattering plane is 12" from the bottom of the ring and o" from the top.An unusually large number of rotating elements —  four besides the target —  should allow one to do coincidence studies with the option of remotely addinq or removing time-of-f5ight, which can degrade other system parameters for certain measurements. Ample targeting should be provided by a target ladder with 5F" of 4" wide target space avai lable.Beam Polarization Source FWHHMeVAE1MeVProtons 80-90% Polarized 500 ±0.6Ion SourceReact i onNeutrons 20% D(p,n) @ 0° 495 - 3gn% D(p,n) § o° 491 ± FYield calculated for 1.7 gm/cm2 LD2 target- 21 -The four detector arms may be changed to suit particular experiments. They mount on four stepped accurately concentric rings which have tapped holes for securing the arms. Remote control of the six re­quired motions is by stepping motor.3•9 A Gas Jet - Mass Identification FacilityA gas jet recoil transport system is being coupled with a time-of- flight mass identification facility to perform spectroscopic studies of interesting short-lived nuclides. At present the irradiation cell of the gas jet is located on beam line IVa (Fig. 1) to intercept the high-energy, high-intensity proton beam. Radioactive reaction pro­ducts recoiling out of a pre-selected target are carried approximately 511 feet to a collection site located in an area of low background. This transport is achieved rapidly (^ 2 sec) and efficiently (^ 70%) by heavy massive species in the carrier gas.At the collection site various detection systems can be positioned for complete spectroscopic studies (a, $, y, n) of radioactive re­action products. Alternatively, a time-of-f1iqht mass identification facility is being assembled for positioning at this site also. This facility will allow precise determination of the mass of radioactive products transported to the collection site.The principle of operation is based upon measuring the time of flight of the heavy fragment of a radioactive decay process occurring at the collector, over a known distance under a pre-determined acceleration field of about 20 kV. This time, which is related to the fragments mass, is generated with a start signal provided by the associated decay process, e.g. a, 53, X ray, y ray, registered in an appropriate detector. The stop signal is provided by the interaction of the heavy fragment in a chevron detector at the end of the flight path. Isotopic identification can be achieved by using an X-ray detector for start signals.- 25 -Crucial to the precise mass determination and optimal operation of the chevron detector is the achievement of pressures in the range of 10-6 torr in the time-of-f1ight system, given that the carrier of the jet system is flowing ('v AO cc/sec). This facility is pre­sently being commissioned.3-10 Fertile to Fissile ConversionSimon Fraser University, under contract with Atomic Energy of Canada Limited, is engaged in a program to study the properties of large targets of U, Th and Pb (with and without a surrounding light watermoderator) under bombardment with protons of energies between 350and 500 MeV.The experimental data are of interest in connection with a conceiv­able off-line nuclear-breeding scheme.The target support structure, moderator tank, and target have been designed and are being constructed. Installation of experimental facilities at TRIUMF is proceeding. No plans exist for using thefacility other than the purposes of the AECL contract.A. THE MESON AREAA . 1 Genera 1The area which is seen to the east of the cyclotron in Fig. 1 is designated the Meson Area. Fig. 1 shows the present configuration: beam line I is a high intensity proton beam running in a tunnel (§ A.2) along the south wall to a single meson production target called T2 (§ A.i ). Channels (§ A.5, A.6, A.7) from the target de­liver pion and muon beams to the experimental areas. Sufficient shielding on beam line I is now thought to be in place to allow operation to the 300 nA level and it is hoped the shielding can be supplemented to increase the current to 10 yA by the spring of 1976. These currents up to 10 yA are being stopped temporarily in the shield of meson source T2 (Fig. A.A). The final plan for- 22 -100 yA operation is to dump it in a "thermal neutron facility" complete with irradiation facilities, built in the east end of the building. (There is a need for such facilities since west­ern Canada has no nuclear reactors.) The target shield at T2 was designed for 20 g/cm2 targets at 100 yA, and is adequate for completely stopping beams only up to a maximum of 10 yA. Conse­quently before 100 yA operation is achieved, the thermal neutron facility and the extension of beam line I past T2 must be com­missi oned.Because of a shortage of funds for the experimental facilities, target T1 , planned for the long section of beam line I upstream of T2 (Fig. 1), has not been installed and work on the high re­solution EE channel (§ 4.6) has been temporarily stopped.4.2 Beam Line I TunnelBeam line I runs 12 ft north of the building wall, 4^ ft above the floor. The tunnel is 'v 16 ft wide and o ft high. The south wall of the tunnel is formed by the building wall, and the north by movable blocks which will total 5o ft in thickness when full power is reached (Thorson, 1968). The overhead beams rest on a corbel which is o ft above the floor in the south wall. The floor is an integral part of the building wall and is n ft thick under ‘ the tunnel. For threshold tt production experiments using the in­itial low proton currents, a thin target position and a temporary cave have been installed upstream of T2 (Fig. 1).4.3 The Meson Production TargetsTarget T1 in beam line I will be limited in thickness to 4 g/cm2 and will provide mesons for the hiqh resolution channel which will be in the southwest corner of the meson area (Fig. 1). Target T 2 , which is now installed, will be limited in thickness to the equiva­lent of 21 g/cm2 of carbon and will provide mesons for the stopped E E x a  channel seen to the north and to the biomedical channel to the south.- 2i -The two targets have the same basic design shown in Fig. A.3 (Hodges, 1970). There is a ladder of stainless steel target cassettes, but water cooling is directed only to the cassette currently in the beam line. Vertical motion by a remotely op­erated jack can bring a selection of thick, thin, beryllium or copper targets into the beam. Molybdenum windows separate the assembly from the beamline vacuum. The windows are cooled by a flow of helium, feeding a helium atmosphere which provides a cushion in case of ruptures in the coolant sheath.Handling is a problem. For instance, the radiation field at 1 meter from 1 cm Cu target one day after shutdown from 100 yA is 100 Rh-5 (Thorson, 1972). The target assembly can be lifted into a vertical flask. All connectors to the target assembly are on top.A .A The Target Shield for T2Fig. A.A shows the conceptual design of the shield for target T2, which is now installed. It consists of three steel cans contain­ing steel and lead with a total weight of 85 tons. It is pierced by holes for the proton and meson lines and forms the vacuum vessel itself. It is sufficiently thick that it can be handled, for re­locating or for disposal, after the induced activity has built up.An alternative demountable shield concept was discarded because of the cost and complication of devices capable of handling the in­duced activity which will be of the order of 511 rads per hour at 5 meter.Vertical holes are provided for the target assembly and meson channel beam blockers. The medical channel blocker is currently carrying the temporary proton beam stop. In the future, when the beam is not stopped in T2, it will carry a collimator which Is needed to scrape the proton beam scattered by the target and there­by reduce activity induced further down the beam line. The most active components are the target assembly, collimator, and beam stop; these are handled vertically with an overhead flask.non-spill water couplingsmicro switches jackedge welded bellows steel shieldinghelium supply to windows helium atercumhjhmedical pion channel windows— target ladder— leak detection deviceTARGET T2 - TRIUMF2>5 TONP R O T O N  S TO P  A N D  M E S O N  S O U R C E .BELLOWSH EL IUM  S U P P L V  TO W IN D OW S- 6 0 2  TARL E A KD E T E C T IO ND E V IC EV 7 \ V /  A W / /'B E A M  ___ /M O N IT O RTEM PORARY  BEAM  STOPCOOLANTT A R G E TLADDERW IN D O W“JACK  FOR POSITIONING .TARGETSS T E E LSH IE LD IN GHEL IUMATMOSPHEREB E A M  B L O C K E R  JA C K IN G  A S S E M B L Y- 2F -h .5 The Proton Beam LineThe quadrupoles in the proton beam line are A" bore before the T1 position and o" afterwards. The combination magnets are mineral insulated so as to be radiation hard, as will be the quadrupoles immediately downstream of the targets. The transport system between the two targets is such that the distribution in phase space of the beam at the first target is reproduced at the second target (Lobb, 1971, 1972).kkdF The High Resolution Pion Channel at T1Because of the shortage of funds, work on the septum and target T1 has stopped and the quadrupoles and power supplies for the channel have been lent to other facilities. The dipoles for the channel have not been ordered. This channel has some unusual features when used for positive pions. Water is used as a convenient targetmaterial rich in hydrogen. The channel is focused on the almostmonoenergetic tt+ which result from the two-body breakup in the reaction pp -* Tr+ d .  This takes advantage of the variable energy capability of TRIUMF; the proton energy is varied to change thepion energy. This results in a relatively high EEl yield, as canbe seen in the second column of Table 4.6.1 (Robertson, 1970).It is estimated (Jones, 1969) that the energy width of the EEl beam will be 3 MeV, roughly equal contributions coming from the energy spread of the proton beam and the variations of energy loss in the target. The choice of water as a target for this channel has in­fluenced the decision to use water cooling on the two targets, although there are disadvantages such as the need for hydrogen- recombining units.The EEl takeoff angle of the channel is as small an angle as possible to obtain the highest energy EEl possible, to minimize the broadeninq of the EE peak from the finite angular acceptance of the channel, and to present the smallest EEl source in the bend plane.- 2g -Table 4.6.1 Positive Pion Yields at T1T H?0 Be D2Q BeITMeV 107 iT+/MeV.sec 106 n /MeV.sec250 n“ 1.2 0.5 0.7200 33 2.4 1.5 2.4150 19 2.4 2.6 3-6100 8 1.5 2.1 3-050 3 0.6 1.7 3-0Yields into 5 mi 11isteradians @ 0°Proton Beam Current 100 pA (" 10 pA)Targets D2O, H2O: 3-7 gm/cm2 Be: 4.6 gm/cm2The final design parameters (Reeve, 1972) are given in Table 4.6.2. The proton beam is a narrow vertical ribbon which passes undeflected on the zero field side of a septum magnet (cf. Fig. 4.6). The pions pass the other side of the septum and get bent 15°- A quadrupole precedes the septum: it does not affect the proton beam since the beam is on the axis, but it doubles the vertical plane acceptance and increases the pion takeoff angle from 2 .n° to an effective angle of n -F °, which eases the septum design.The proton beam at the target will be a vertical ribbon of dimension 1 mm by 10 mm (Lobb, 1972). The setting of the quadrupole between the target and the septum presents a problem in that it accepts both pions for the channel and protons for main beam line. The quadru­pole will be set (Lobb, 1972) so that pions of the energy of inter­est see a specified k-value (square root of the ratio of field gradient to the particle rigidity). The k-value seen by the protons depends on the relation between the EEl  and d energies in the pp ->■ irdcthkby — k3- 28 -Fig.  4.6- 2. -reaction. A consistent set of settings of the quadrupoles between T1 and T2 has been calculated (Lobb, 1972) to retain the proton focus at T2 for all EE energies.Table 4.6.2Summary of Channel PerformanceParameterMxMyD (cm % PQ )R2F (mr/% PQ )1st order resolution (± % P )o2nd " " "± x (cm)± y (cm)Position in Channelmax values(mr) max values± y 5 (mr)n (msr)e (Trmmm r ) x(Trmmmr)AP (± % P ) oLength (m)midpoi nt -  0.225 .42 5-6 0.02 < 0 .36* 0.2  6.5 70 176 . 0end0.460.021.70.054451710.544080055535System not optimized for 2nd order.- i1 -4• 7 The Stopped FExp ChannelThe stopped EEx p channel shown in Fig. 4.7 is primarily designed to provide stopping FE and p beams of either polarity but, because of the temporary suspension of work on the high resolution channel (§ 4.6), it will also be used for EE scattering experiments. The quadrupoles are 12" in diameter, B1 and B2 have 10" gaps, and B3 has a 12Jg" gap. The maximum momentum is 160 MeV/c.The channel is seen to have the large take-off angle of 135°- Thisshould reduce the flux fast neutrons from the target by about threeorders of magnitude compared to the forward direction. Also the use of a 5in ° take-off angle greatly reduces the electron contamination according to preliminary results. The LASL data gave some indica­tion that the pion production may be isotropic below 100 MeV/c.This has been confirmed by a recent experiment at SREL and TRIUMF. Finally, the use of a large take-off angle will present a relativelysmaller projected EE source to the channel.The large take-off angle would not be suitable for high energy muons but there have been no requests for energetic muons at TRIUMF. De­tails of the construction have been given by Beer (1974).Modes of Operation1) When operating in the mode for stoppi ng p's wi th low EE , n and y contamination, the channel consists of three sections:- a EE injection system (0.1 02 B1 0.3 B2 Q4 Q5) which is designed to be achromatic to maximize the flux;- a straight section (QF 07 1.o) which, together with Q4 and 05, allows in-flight decay of the it's; and- a momentum selection magnet (B3) to select the lower momentum p's from tt 5 s which decay into the backward cone.The vacuum in the channel extends downstream to a window after Qo . A helium bag may be used in B3.horizontal and vertical slits- i2 -The p's are stopped at the point labelled "backward analysed p's" in Fig. 4.7. When operating in this mode, a parasite beam of pions and forward-decay muons will be available at the point labelled "parasite mesons" in Fig. 4.7- The only restriction on users of the parasite beam is that the prime user (of backward analysed muons) must be well shielded from neutrons originating at the parasite pion stop.2) For experiments needing the highest tt flux with minimum p con­tamination, the channel is operated in a mode in which there is a "primary EE focus" 1 meter following Qn (cf. Fig. 4.7)- The triplet 0.6 Q.7 Qo , which is on a single stand on airpads, is re­moved in this mode, and the window from the flange after Qo ismoved to the flange following Q5.The process of moving the magnets to allow access to the primary EE focus discussed above is disruptive and suggests another mode of operation which would be suitable for those EE experiments which can tolerate a smaller EE flux and a larger p contamination.3) In this mode B3 is turned off but left in place and the triplet QF Q.7 13o is used to move the FE focus to the "secondary EE focus"shown in Fig. 4.7- Thus the channel can be changed from pro­ducing EE ' s at the secondary EE focus to producing backward-decay p's in a few minutes, since only magnet current need be changed.The InjectorThe predicted characteristics of the channel are given in Table 4.7. Final measurements are not yet available. The optics up to the slit box are the same in both modes of operation of the injector region. Beyond the slits the design has been optimised to suit either the backward muon users or the pion users. The momentum spread of the beam in the second half of the channel and 2nd order effects can be controlled using the slits.- ii -Table 4.7 Optics of M9 Injector RegionPa rameter M i dp 5ane Slit Pos i t ionEnd Muon ModeEnd Pi on ModeFoe iMaan i f i cat i onsDispersion {cm/%? ) oR2F ( m r A P Q )V/a i s t sSoli d Angle (mstr)Momentum Acc. (± %? )ox and yMx = .69 My = - (m)Typical 1st order x (±cm)t -Typical 1st order y (+cm) 13Typical 2nd order x (+cm)f(AP = ±7%, Ax' = ±21 mr)Typical 2nd order y (+cm)5st order resolution withf ± i1311 5 32 x 25 5A 7-9 4 13 613x and yM = 1 . 4 6xMy = .97 1 235y25148.450.570.5± i-F  cm long source )t These values for a 10 cm long production target.- is -To maximize the flux of backward muons, one must inject as large an emittance pion beam as possible into the straight section QF Q.7 0.8. The results of the optimised calculations are shown in Table 4.7-4 3o The Biomedical Pion ChannelThe medical channel delivers a tt beam from the T2 target into the biomedical annex. It is funded by the B.C. Cancer Foundation and the Health Resources Fund to investigate the effectiveness of pions for radiotherapy. A period of particle counting experiments, dosi~ metry, cellular and animal radiobiology will precede the human radiotherapy. The biomedical facility, like the rest of TRIUMF, is open to any users on the basis of acceptance of a written experi- menta 5 proposa5 .The channel has a vertical takeoff of 30°- it is an achromatic system consisting of two 45° bending magnets, three 52" aperture quadrupoles, two o" quadrupoles, and two sextupoles for the correction of second order aberrations (Fig. 4.8).Table 4.8Biomedical Pion Channel CharacteristicsTakeoff angle: 30° in forward directionDistance from T2 target to first quadrupole:5 meterBeam acceptance: 10 msrMomentum resolution: ± 1%Momentum acceptance: ± 50%Maximum pion energy: 110 MeVSize of uniform radiation field: continuouslyvariable up from i  x i  cmSpatial uniformity of beam: ± n%Maximum dose rate: 20 rads/minTotal length of channel: o meters- in -Q -  Quadrupole Focussing Magnet B -  Dipole Bending MagnetS -  Sextupole Magnet- iF -4.9 Thermal Neutron FacilityDuring initial operations the protons in beam line I w i 11 be stopped downstream of target T2 in the T2 target shield. The maximum current which can be stopped in this way is thought to be 10 pA.When funds become available, the proton beam will be stopped in a facility (Thorson and Arrott, 1971) designed to make use of the resulting neutrons. No thermal neutron irradiation facilities presently exist in Western Canada. The 100 pA proton beam will be transported from T2 to a 15 cm diameter Pb-Bi target located in the southeast corner of the meson area (Fig. l). The target will be surrounded by 521 cm diameter heavy water, graphite moderated assembly with a water reflector. With 100 pA incident beam of protons at 500 MeV, the maximum useful thermal neutron flux will be 'v 13. x 51ii  cm-2 sec-3,4.10 The MSR Faci1i tyThe MSR secondary beam line was a late addition to the meson area facilities around target T 2 , designed to salvage some of the pions lost into the unused solid angle. Built with small borrowed magnets and restricted by existing beamline plans to the region at nn° to the proton beam, it was not intended to compete with the main stopped ir/p channel, but to accommodate users desiring a modest flux of polarized muons in situations where beam purity is not critical.In particular, the channel will be employed in chemical and solid state physics studies using the technique of Muon Spin Rotation (MSR). In this funct ion, it will be served by an existing data acquisition system comprised of general purpose MSR-oriented count­ing and measuring apparatus interfaced to a sophisticated on-line computer with extensive supporting software. It is hoped that this facility will help make MSR more available as a research tool to various interested groups. When appropriate, the MSR computer will also serve the stopped ir/p channel. Time-shared use of the MSR computer by other groups at TRIUMF is encouraged.- ig -The MSR channel is designed to be used as a muon channel in two modes. In the "conventional mode", positive or negative pions are collected into a crudely momentum-selected beam and allowed to decay into muons, which are then momentum analyzed to form a polarized muon beam. When optimally tuned for muons from forward- decaying pions, the channel should produce on the order of 5 x 51n y+/sec and 10g ir+/sec into a 10 cm x 10 cm target at 100 yA proton current. For a "backward muon" tuning, the equivalent muon rates are about a factor of n lower, but the pion contamination is small.Rates for negative pions and muons are about a factor of 3 loweri n genera 5.In the "Arizona Mode", positive muons from the decay of pions at rest in the surface of the production target are collected directly into a nearly monochromatic beam of very low energy (4.1 MeV).These highly polarized muons can be stopped in a thin foil or a few inches of gas at atmospheric pressure, and are particularly useful for MSR studies in gases and rare solids. Negative muons cannot be obtained in this fashion, due to capture of the stopped F E c  by nuclei. Since only those pions which stop just at the surface of the production target contribute to the muon flux, rates in this mode are apt to depend critically upon target geometry, and are difficult to estimate reliably. By selecting an optimal target shape it should be possible to obtain rates at least competitive with those expected in the "conventional mode".The channel could also be used for pions in many applications where a muon contamination is not harmful; the pion momentum is variable from essentially zero up to about 170 MeV/c, with a normal resolu­tion of approximately ± 2.5%.- io -5. INSTRUMENTATION POOLA pool of nucleonic instrumentation is available to users on a rental basis. Basically, the pool is intended as a store of nucleonic in­strumentation available for use by scientists at TRIUMF in approved experiments. While "new" (i.e., during the first four years of residence of such instrumentation at TRIUMF), the instrumentationwill be rented at a rate of 2% of the capital cost of the instru­mentation per month for the first three years, decreasing to 5% permonth for the fourth year. After the instrumentation has been "paidoff" it would be available free of charge to approved users. TRIUMF instrumentation in use in an experimental program is to be returned to the pool upon completion of that program. Until the inventory of instrumentation in the pool is built up, requests for such "rented" instrumentation must be submitted by the users to the pool at the budget time. All instrumentation purchased by the pool will be subject to detailed acceptance tests.The TRIUMF electronics shop will endeavor to provide free maintenance of all nucleonic instrumentation owned by TRIUMF, in use on experi­ments, providing such instrumentation is described in Table 5, "TRIUMF Pool Standard Nucleonic Instrumentation". Non-standard instrumentation can also be submitted to the shop for repair. In this case, users will be assessed costs at the current rate.- i. -Table 5TRIUMF Pool Standard Instrumentation (1 July 1975)1. RACKSPremier Metal Housings (Montreal)2. POWER SUPPLIES, BINS and CRATESNIM binsBin and power supply: B.L. PackerCAMAC crateC rate : GEC E 1 1 i ottPower supply: B.L. PackerPhotomultiplier high voltage:High voltage distribution:3. PHOTOMULTIPLIERS and HOUSINGS2 in. 52-stage, bi-alkali photomu55 i p 5i ers:Hous i ngs:4. NIM MODULESFast NIMDiscriminators, quad updating: bridged input version: quad zero-cross: constant faction:Type 000003070Bin NB10200 W power supply 1001VC0011/CP 1 1031 BC (300 W)Power Designs 1570TRIUMF THV100RCA 8575R or RCA 8850R N.P.W. England Ltd.LRS 621L LRS 621L/4 EGG T140 NL 0RTEC 453, 463AND (coincidence) gates:Triple 4-fold logic: LRS 465(Dual 4-fold majority logic LRS 364 and iFn  accepted, but not recommended)Dual 4-fold overlap: TRIUMF B024Quad 2-fold overlap: TRIUMF B042Quad 2-fold AND/OR (updating): LRS 622(LRS 322A accepted but not recommended)OR gates and logic fan-out: Logic o-fold fan-out OR gate: Dual 4-foldTRIUMF 14X2951 TRIUMF 14X3001EGGF304 and LRS 429 under evaluationLinear Fan-!n/Fan-out LRS 428(LRS 127 and 128 accepted but not recommended)Linear gate:Linear gate and stretcher (integrator)Borer 330 EGG LG 105/NNIM MODULES (continued)Level converter (NIM Fast-<“ -^Slow): LRS Foo AL and EGG LI io O/NLGate pulse and delay generator: EGG GG202Scaler (visual display) 100 MHz, F digitDual unit: Joerger VS(ORTEC 772 accepted but not recommended)Variable delay units (cable-switched)Passive '64 nsec5 TRIUMF BO 07Variable attenuators (50 ft): LRS A101 LFast pulse generator (Berkeley): BNC 8010High resolution ADC:51-bit amplitude encoder (requiresscaler for read-out): EGG EA 101/NHigh resolution TDC:51-bit time encoder (requiresscaler for read-out): EGG ET 102/NSpark chamber TDC (routing unit), clock generator (up to 200 MHz) and scaler required. Dual unit: TRIUMF B0 0100Slow NIMgated biased amplifier ORTEC 444research ampli fier 450timing filter amplifier 45^del ay 5i ne amp 5i f ier 460delay ampli fier 427A5 i near gate 426linear gate and stretcher 442fast coincidence 414Auniversal coincidence 41oAtime-to-pu5se height converter 467gate and delay generator 41FAprecision pulse generator 4135 kV power supply 459constant fraction timing SCA 455digital current integrator 439- s5 -5. CAMAC MODULEScoincidence buffer (pattern unit)dual 52-fold:multi-ADC, octal o-bit units:multi-TDC, quad 9-bit:octal 51-bit:scalers, hex 24-bit, 100 MHz:crate A controller:EGG C212LRS 2248 or NE 9040LRS 2226A LRS 2228Kinetics 3615Kinetics 3900(GEC Elliott accepted but not recommended)TTY output:5F-b i t (relay-type) output register: 24-bit (TTL) output register 24-bit in/out (TTL) register:24-bit input gate SEC dual 24-bit input gate:16-fold fast NIM out, SEN:256-bit input gate (for MWPC) GEC:NE 7061-1 GEC 0D 1606 GEC PR 612 NE 9017 PG 604 Jorway 61-1 OR 0207 vH 2nF- s2 -REFERENCESA)-Qazzaz, N. "The Design of Pion and Muon Channels", T R 1— 1—72— 1Beer, G.A., R.M. Pearce, P.A. Reeve, L.P. Robertson. "Proqress Report on the Stopped EExy Channel", VPN-74-4Dilworth, Secord, Meagher and Associates Limited, and William M. Brobeck S Associates. "Conceptual Design of RF Resonators for a 500 MeV H~ Cyclotron" , TRI -70-2Dutto, G., C.J. Kost, M.K. Craddock. "Differences between Operation with Fundamental and Third Harmonic", TRI-DN-72-3Dutto, G., C.J. Kost, G.H. Mackenzie, M.K. Craddock. "Optimization of the Phase Acceptance of the TRIUMF Cyclotron". Presented at VI International Cyclotron Conference, Vancouver, B.C., June 1972Erdman, K.L., R. Poirier, O.K. Fredriksson, J.F. Weldon and W.A. Grundman. "TRIUMF RF Amplifier and Resonator System"Fleming, E.D. "Positive Muon Depolarization Phenomena in Chemical Systems", TRIUMF Proposal 35 (1972)Harrison, R.W. "A beam Transport System for the Medical Channel at TRIUMF", TRI-72-1Hodges, T.A. "Pion Production Targets - Design Concept", VPN-70-17Hodges, T.A. "Design of a High Power Liquid H2/D2 Target for TRIUMF",TRI- 1-73-2Jones, Garth. "Pion Beam Channels", TRI-DN-F.-i2Kitching, P. and G.M. Stinson. "A Medium Resolution Spectrometer Built from HRS Components", TRI-DNA-72-4Lobb, D.E. "Current Status of the Design of Beam Line I to Target Tl", VPN-71-18Lobb, D.E. "Proton Beam Transport from Thin Target Tl to Thick Target T3 in Beam Line I", VPN-72-6Mackenzie, G.H. "Beam Quality at Extraction", TRI-DN-71-49Mackenzie, G.H. "Simultaneous Extracted Beams", file 54A, 2 December 1971Measday, D.F. "Monokinetic Neutron Beam in the Ranqe of 50 MeV to 150 MeV", Nuol. Instv. and Meth., 40 (1.FF ) 213- si -Pearce, R.M. "Experimental Facilities Planned at TRIUMF", TRI — I—73“ 1Reeve, P.A. "Conceptual Design of a 'Pre-Ouad5 Scattering Pion Channel", VPN-71-22Richardson, J.R. "Energy Resolution in a 500 MeV H" Cyclotron",TRI-69-6Richardson, J.R. and M.K. Craddock. "Beam Quality and Expected Energy Resolution from the TRIUMF Cyclotron", Proc. Int. Conf. on Cyclotrons, Oxford, September 1969Richardson, J.R. et al. "700 MeV Neqative Hydrogen Ion CyclotronFacility", UCLA Report, 1963, and Nual. Instr. & Meth. , 24_ (1963) 493Richardson, J.R. "The Present Status of TRIUMF", VI International Cyclotron Conference, Vancouver, B.C., June 1972Robertson, L.P. "Extraction of Protons and the Production of Secondary Beams from TRIUMF", VPP-70-2Robertson, L.P. Preliminary results from SREL EE production experiment (1972)Stinson, G.M. and P. Kitching. "Optimized Second Order Design for TRIUMF High Resolution Proton Spectrometer", TRI-DNA-72-3Stinson, G.M., P.A. Reeve, D. Fleming and P. Kitching. "Conceptual Design of the Proton Spectrometer", TRI -P NA-72-1Stinson, G.M., W.C. Olson, W.J. McDonald, P. Ford, D. Axen, E.W. Blackmore. "Electric Dissociation of H“ Ions by Magnetic Fields", Nuol. Instr.& Meth. , 74. (1969) 333Tautz, M.F, and L.P. Robertson. "Possible Extraction Transport Systems for the Six Extracted Beams from the TRIUMF Accelerator", VPN-70-25Thorson, I.M. "Shielding and Activation in a 500 MeV H” Cyclotron Faci1ity", TRI-68-4Thorson, I.M. and A.S. Arrott. "Conceptual Design of the TRIUMF Thermal Neutron Facility", TRI -71~ 3Eb


Citation Scheme:


Citations by CSL (citeproc-js)

Usage Statistics



Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            async >
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:


Related Items