SB2009 Proposal (Working Assumptions for ALCPG)
Rev. 20091105A
General Parameters / May 2009 DESY Meeting Summary
RDR SB2009 comment
Beam and RF Parameters
No. of bunches 2625 1312 low-power option
Bunch spacing ns 370 740
beam current mA 9 4.5
Avg. beam power (250 GeV) MW 10.8 5.4
Accelerating gradient MV/m 31.5 31.5
Pfwd / cavity (matched) kW 294 147
Qext (matched) 3.00E+06 3.00E+06
tfill ms 0.62 1.13
RF pulse length ms 1.6 2
RF to beam efficiency % 61 44
IP Parameters
Norm. horizontal emittance mm.mrad 10 10
Norm. vertical emittance mm.mrad 0.040 0.035
bunch length mm 0.3 0.3
horizontal β* mm 20 11
horizontal beam size nm 640 470
no trav. with trav.
focus focus
vertical β* mm 0.4 0.48 0.2
vertical beam size nm 5.7 5.8 3.8 (?)
Dy 19 25 21
δEBS/E % 2 4 3.6
Avg. PBS kW 260 200 194
Luminosity cm -2 s -1 2.00E+34 1.50E+34 2.00E+34
General Layout Assumptions / May 2009 DESY Meeting Summary
RDR SB2009 Comments
RTML / Main Linac housing service + beam tunnel single (beam) tunnel
HLRF Configuration A Configuration B
Layout 10MW MBK driving 26 cavities Surface Klystron Cluster DRFS
Num. of klystrons (both linacs) 560 × 10MW MBK ~280 × 10MW MBK ~3600 × 800kW MAK
Location Service tunnel Surface buildings (every ~2km) Beam tunnel
PDS distribution system connecting three 800kW MAK directly drives 4 adjacent
cryomodules (26 cavities) via penetrations • 18x10MW MBK cluster • 180 MW transport cavities locally.
between service and beam tunnel. via overmoded WG into tunnel • Drives
~1000 cavities
Modulators 560 Bouncer-type modulator in service ~230 Marx-type modulator located in surface ~3600 MA modulators distributed in tunnel.
tunnel cluster buildings
RTML/ML power supplies, electronics located in service tunnel located in tunnel located in tunnel
Damping Ring 2x 6.7 km circumference ring 2x 3.2 km race-track ring
Damping Ring bunch length 9 mm 6 mm
Bunch Compressor two-stage, compression x40 (max) single-stage, compression x20
Positron source undulator @ 150 GeV point undulator at exit of ML (250 GeV)
Positron source yield (e+/e-) 1.5 ~2 at 250 GeV (TBC)
Positron capture device pulsed flux concentrator QWT
Length of undulator ~200m TBD
few % auxiliary source integrated into beam tunnel, using same target and capture
Aus. Positron source Independent 10% charge “keep alive” source
sections.
General central region integration
• Undulator source now integrated between ML exit and start of BDS • Integrated auxiliary source (few %) using primary photon target and capture/acceleration • electron source
integrated in upstream positron BDS tunnel • optimised (minimum) use of shafts, etc.
• Integrated auxiliary source (few %) using primary photon target and capture/acceleration.
• Electron source integrated in upstream positron BDS tunnel.
• Optimized (minimum) use of shafts, etc.