Real Time - alternating-gradient
Imox: Fringe field simulations of a non-scaling FFAG accelerator. (arXiv:1202.0805v1 [physics.acc-ph])
5 February 2012, 8:15 pm
Imox
Fringe field simulations of a non-scaling FFAG accelerator. (arXiv:1202.0805v1 [physics.acc-ph]) - http://arxiv.org/abs/1202.0805
February 5
from physics updates on arXiv.org
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Fixed-field Alternating Gradient (FFAG) accelerators offer the potential of high-quality, moderate energy ion beams at low cost. Modeling of these structures is challenging with conventional beam tracking codes because of the large radial excursions of the beam and the significance of fringe field effects. Numerous tune resonances are crossed during the acceleration, which would lead to beam instability and loss in a storage ring. In a non-scaling FFAG, the hope is that these resonances can be crossed sufficiently rapidly to prevent beam loss. Simulations are required to see if this is indeed the case. Here we simulate a non-scaling FFAG which accelerates protons from 31 to 250 MeV. We assume only that the bending magnets have mid-plane symmetry, with specified vertical bending field in the mid-plane (y=0). The magnetic field can be obtained everywhere using a power series expansion, and we develop mathematical tools for calculating this expansion to arbitrary order when the... - Imox
Imox: On deflection fields, weak-focusing and strong-focusing storage rings for polar molecules. (arXiv:1105.1913v1 [physics.atom-ph])
10 May 2011, 7:57 pm
Imox
On deflection fields, weak-focusing and strong-focusing storage rings for polar molecules. (arXiv:1105.1913v1 [physics.atom-ph]) - http://arxiv.org/abs/1105.1913
May 10, 2011
from physics updates on arXiv.org
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In this paper, we analyze electric deflection fields for polar molecules in terms of a multipole expansion and derive a simple but rather insightful expression for the force on the molecules. Ideally, a deflection field exerts a strong, constant force in one direction, while the force in the other directions is zero. We show how, by a proper choice of the expansion coefficients, this ideal can be best approximated. We present a design for a practical electrode geometry based on this analysis. By bending such a deflection field into a circle, a simple storage ring can be created; the direct analog of a weak-focusing cyclotron for charged particles. We show that for realistic parameters a weak-focusing ring is only stable for molecules with a very low velocity. A strong-focusing (
alternating-gradient) storage ring can be created by arranging many straight deflection fields in a circle and by alternating the sign of the hexapole term between adjacent deflection fields. The acceptance of... - Imox
Imox: Stark deceleration of CaF molecules in strong- and weak-field seeking states. (arXiv:1104.3976v1 [physics.atom-ph])
20 April 2011, 7:47 pm
Imox
Stark deceleration of CaF molecules in strong- and weak-field seeking states. (arXiv:1104.3976v1 [physics.atom-ph]) - http://arxiv.org/abs/1104.3976
April 20, 2011
from physics updates on arXiv.org
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We report the Stark deceleration of CaF molecules in the strong-field seeking ground state and in a weak-field seeking component of a rotationally-excited state. We use two types of decelerator, a conventional Stark decelerator for the weak-field seekers, and an alternating gradient decelerator for the strong-field seekers, and we compare their relative merits. We also consider the application of laser cooling to increase the phase-space density of decelerated molecules. - Imox
