TY  - JOUR
AU  - Scandale, W. et al
AU  - Lari, L.
PY  - 2013
DA  - 2013//
TI  - Optimization of the crystal assisted collimation of the SPS beam
T2  - Phys. Lett. B
JO  - Physics Letters B
SP  - 182
EP  - 186
VL  - 726
IS  - 1-3
PB  - Elsevier Science Bv
KW  - Accelerator
KW  - Beam collimation
KW  - Crystal
KW  - Channeling
AB  - The possibility for optimization of crystal assisted collimation has been studied at the CERN SPS for stored beams of protons and Pb ions with 270 GeV/c per unit charge. A bent silicon crystal used as a primary collimator deflects halo particles in the channeling regime, directing them into a tungsten absorber. In channeling conditions a strong reduction of off-momentum particle numbers produced in the crystal and absorber, which form collimation leakage, has been observed in the first high dispersion (HD) area downstream. The present study shows that the collimation leakage is minimal for some values of the absorber offset relative to the crystal. The optimal offset value is larger for Pb ions because of their considerably larger ionization losses in the crystal, which cause large increases of particle betatron oscillation amplitudes. The optimal absorber offset allows obtaining maximal efficiency of crystal-assisted collimation.
SN  - 0370-2693
UR  - https://doi.org/10.1016/j.physletb.2013.08.028
DO  - 10.1016/j.physletb.2013.08.028
LA  - English
N1  - WOS:000326482200020
ID  - Scandale+Lari2013
ER  -