TY - JOUR

T1 - Arclike variable bunch compressors

AU - Williams, Peter H.

AU - Pérez-Segurana, Gustavo

AU - Bailey, Ian R.

AU - Thorin, Sara

AU - Kyle, Bill

AU - Svensson, Jonas Björklund

N1 - 8 pages

PY - 2020/10/13

Y1 - 2020/10/13

N2 - Electron bunch compressors formed of achromat arcs have a natural advantage over the more commonly used chicane compressors in that linearisation of the longitudinal phase space is of the correct sign to compensate for the curvature imprinted by rf acceleration. Here we extend the utility of arc compressors to enable variation of the longitudinal compaction within a fixed footprint. We also show that this variability can be achieved independently order-by-order in momentum deviation. The technique we employ consists of additional dipoles, leading to the advantageous property that variability can be achieved without incurring significant penalty in terms of chromatic degradation. We show this by comparison to an alternative system where additional quadrupoles are utilised to enable variation of momentum compaction. Each of these alternative approaches are being considered in the context of an upgrade of the MAX IV linac, Sweden, to enable a soft X-ray free-electron laser (FEL) in addition to its existing functions.

AB - Electron bunch compressors formed of achromat arcs have a natural advantage over the more commonly used chicane compressors in that linearisation of the longitudinal phase space is of the correct sign to compensate for the curvature imprinted by rf acceleration. Here we extend the utility of arc compressors to enable variation of the longitudinal compaction within a fixed footprint. We also show that this variability can be achieved independently order-by-order in momentum deviation. The technique we employ consists of additional dipoles, leading to the advantageous property that variability can be achieved without incurring significant penalty in terms of chromatic degradation. We show this by comparison to an alternative system where additional quadrupoles are utilised to enable variation of momentum compaction. Each of these alternative approaches are being considered in the context of an upgrade of the MAX IV linac, Sweden, to enable a soft X-ray free-electron laser (FEL) in addition to its existing functions.

KW - physics.acc-ph

U2 - 10.1103/PhysRevAccelBeams.23.100701

DO - 10.1103/PhysRevAccelBeams.23.100701

M3 - Journal article

VL - 23

JO - Physical Review Accelerators and Beams

JF - Physical Review Accelerators and Beams

SN - 2469-9888

IS - 10

M1 - 100701

ER -