TY - ELEC
AU - Vered Rom-Kedar
PY - 2018
TI - Exponential Fermi accelerators in closed and open geometries and on energy equilibration
LA - eng
M3 - Moving Image
AB - In 1949, Fermi proposed a mechanism for the heating of particles
in cosmic rays. He suggested that on average, charged particles gain
energy from collisions with moving magnetic mirrors since they hit
the mirrors more frequently with heads on collisions. Fermi, Ulam
and their followers modeled this problem by studying the energy gain
of particles moving in billiards with slowly moving boundaries. Until
2010 several examples of such oscillating billiards leading to power-
law growth of the particles averaged energy were studied. In 2010
we constructed an oscillating billiard which produces exponential in
time growth of the particles energy [1]. The novel mechanism which
leads to such an exponential growth is robust and may be extended to
arbitrary dimension. Moreover, the exponential rate of the energy gain
may be predicted by utilizing adiabatic theory and probabilistic models
[2,3]. The extension of these results to billiards with mixed phase space
leads to the development of adiabatic theory for non-ergodic systems
[4]. Finally, such accelerators lead to a faster energy gain in open
systems, when particles are allowed to enter and exit them through
a small hole [5]. The implications of this mechanism on transport in
extended systems [6] and on equilibration of energy in closed systems like springy billiards will be discussed [7].
These are joint works, mainly with with K. Shah, V. Gelfreich and
D. Turaev [1-5],[7] and [6] is with M. Pinkovezky and T. Gilbert:
[1] K. Shah, D. Turaev and V. Rom-Kedar, Exponential energy
growth in a Fermi accelerator, Phys. Rev. E 81, 056205, 2010.
[2] V. Gelfreich, V. Rom-Kedar, K. Shah, D. Turaev, Robust expo-
nential accelerators, PRL 106, 074101, 2011.
N2 - In 1949, Fermi proposed a mechanism for the heating of particles
in cosmic rays. He suggested that on average, charged particles gain
energy from collisions with moving magnetic mirrors since they hit
the mirrors more frequently with heads on collisions. Fermi, Ulam
and their followers modeled this problem by studying the energy gain
of particles moving in billiards with slowly moving boundaries. Until
2010 several examples of such oscillating billiards leading to power-
law growth of the particles averaged energy were studied. In 2010
we constructed an oscillating billiard which produces exponential in
time growth of the particles energy [1]. The novel mechanism which
leads to such an exponential growth is robust and may be extended to
arbitrary dimension. Moreover, the exponential rate of the energy gain
may be predicted by utilizing adiabatic theory and probabilistic models
[2,3]. The extension of these results to billiards with mixed phase space
leads to the development of adiabatic theory for non-ergodic systems
[4]. Finally, such accelerators lead to a faster energy gain in open
systems, when particles are allowed to enter and exit them through
a small hole [5]. The implications of this mechanism on transport in
extended systems [6] and on equilibration of energy in closed systems like springy billiards will be discussed [7].
These are joint works, mainly with with K. Shah, V. Gelfreich and
D. Turaev [1-5],[7] and [6] is with M. Pinkovezky and T. Gilbert:
[1] K. Shah, D. Turaev and V. Rom-Kedar, Exponential energy
growth in a Fermi accelerator, Phys. Rev. E 81, 056205, 2010.
[2] V. Gelfreich, V. Rom-Kedar, K. Shah, D. Turaev, Robust expo-
nential accelerators, PRL 106, 074101, 2011.
UR - https://open.library.ubc.ca/collections/48630/items/1.0377738
ER - End of Reference