4-twist helix snake to maintain polarization in multi-GeV proton rings
oleh: F. Antoulinakis, Y. Chen, A. Dutton, E. Rossi De La Fuente, S. Haupert, E. A. Ljungman, P. D. Myers, J. K. Thompson, A. Tai, C. A. Aidala, E. D. Courant, A. D. Krisch, M. A. Leonova, W. Lorenzon, R. S. Raymond, D. W. Sivers, V. K. Wong, T. Yang, Y. S. Derbenev, V. S. Morozov, A. M. Kondratenko
| Format: | Article |
|---|---|
| Diterbitkan: | American Physical Society 2017-09-01 |
Deskripsi
Solenoid Siberian snakes have successfully maintained polarization in particle rings below 1 GeV, but never in multi-GeV rings, because the spin rotation by a solenoid is inversely proportional to the beam momentum. High energy rings, such as Brookhaven’s 255 GeV Relativistic Heavy Ion Collider (RHIC), use only odd multiples of pairs of transverse B-field Siberian snakes directly opposite each other. When it became impractical to use a pair of Siberian Snakes in Fermilab’s 120 GeV/c Main Injector, we searched for a new type of single Siberian snake that could overcome all depolarizing resonances in the 8.9–120 GeV/c range. We found that a snake made of one 4-twist helix and 2 dipoles could maintain the polarization. This snake design could solve the long-standing problem of significant polarization loss during acceleration of polarized protons from a few GeV to tens of GeV, such as in the AGS, before injecting them into multi-hundred GeV rings, such as RHIC.