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MACHINE ASPECTS OF SPIN-FILTERING EXPERIMENTS |
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B. Lorentzª for COSY- Jülich and the PAX collaboration Forschungszentrum Jülich GmbH, Jülich, Deutsch ª – corresponding author |
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No paper Slides |
Contribution not received |
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MAGNETOOPTIC STRUCTURES FOR SYNCHROTRONS WITH NEGATIVE MOMENTUM COMPACTION FACTORS |
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Yu.V. Senichevª¹² ¹Institut für Kernphysik, Forschungszentrum Jülich GmbH, Jülich, Deutsch ²Institute for Nuclear Research of Russian Academy of Sciences, Moscow, Russia Abstract In synchrotrons the transition energy Wtr=m0c2(γtr- 1) is fundamentally important because it determines the maximum attainable accelerated currents. From this point of view it is desirable that the momentum compaction factor α= 1/γtr2 be as small as possible or even negative, which makes γtr imaginary and accordingly rules out transition energy crossing by particles under acceleration. On the basis of the theory of "resonant" lattices for synchrotrons with complex transition energy developed in [1, 2], examples of such lattice with application to various accelerators are proposed. The "resonant" lattice was first proposed for the Moscow Kaon Factory [3]. This lattice was then adapted for the TRIUMF KAON Factory [4]. Later it was considered as the best candidate for the Low Energy Booster of Superconducting Super Collider [5], then was adopted for the main accelerator of the Neutrino Factory at CERN [6], and ultimately was implemented in the Japan Protons Accelerator Research Center [1, 7]. In the Superconducting option of High Energy Storage Ring lattice of the FAIR project the same idea is also accepted [8]. At present the "resonant" lattice is one of the candidates for PS2 in CERN [9]. The "resonant" lattice is appeared to be useful for electron machines as well. In particular, in the electron-positron collider type a small momentum-compaction factor is needed to reduce the synchrotron tune, while keeping the bunch length and momentum spread constant [1]. In synchrotron-light sources the minimum momentum-compaction factor and the minimum modulation of the dispersion function are both required simultaneously to have a small horizontal emittance [10, 11]. ª – corresponding author |
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