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Plan and Opportunities for Migration and Integration of the Photoinjector into New Muon Lab. Mike Church AAC Review - 12/5/06. Current Photoinjector Layout at A0. 13m. (CC-1). P. Piot. Proposed NML Injector Layout (latest design). 22m. (CC-1, CC-2).
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Plan and Opportunities for Migration and Integration of the Photoinjector into New Muon Lab Mike Church AAC Review - 12/5/06
Current Photoinjector Layout at A0 13m (CC-1) P. Piot Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Proposed NML Injector Layout (latest design) 22m (CC-1, CC-2) (intended initially for ILC crab cavity tests) P. Piot Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
NML Building Layout (front end) u.s end of 1st cryomodule egun 3rd cryomodule (if no building extension) Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Tentative Schedule • Photoinjector operations will continue at A0 through CY07 • The move of the A0 photoinjector will be delayed until 1/08 so that T. Koeth’s thesis experiment can be completed • Upgrades that are planned at A0 before moving to NML include the following • laser: upgrade 2-pass and multipass flash lamp pumped cavities to diode laser pumped cavities • addition of downstream off-axis beamline for emittance exchange experiment (T. Koeth’s thesis) • New egun and modulator will be developed • A0 gun suffers E-field breakdown in RF-coupling slot for pulse lengths >300 msec • Modulator needs upgrade to operate at 5 Hz and 1msec pulse length • 2nd TESLA cavity (CC-2) is being conditioned at Meson Detector Building • 3rd harmonic cavity: will not be ready in early CY08 • We estimate the move can be accomplished in ~4 months (not including beam commissioning) • We expect egun, modulators, and CC-2 to be ready for installation in early CY08 Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
PITZ Egun (Photo Injector Test Facility at DESY Zeuthen) RF coaxial feed 1 ½ cell RF cavity (1.3 GHz) photocathode laser mirror Capable of delivering ILC beam parameters, with normalized transverse emittance ~4E-6 Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Photoinjector Upgrades for NML • Laser - no additional major upgrades for NML • Egun – entirely new – similar to PITZ egun design; capable of ILC beam parameters • Egun modulator – upgrade: 1 Hz 5 Hz; 300 msec 1 msec • Beamline – higher energy decreased dp/p • 3rd harmonic cavity – shorter bunch length; higher peak current • Instrumentation – (possibly) new BPM’s • Off-axis beamline – addition of a 4-dipole dogleg will provide an off-axis beamline for testing ILC crab cavities, emittance exchange experiment, and other tests • Better integrated controls system – • Increased experimental areas – see P. Piot’s talk Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Downstream Beamlines at NML diagnostic section spectrometer magnet (dE/E ~1E-4) high energy test area low power dump beam spot size required to be >3mm No room to slide cryomodules downstream! high power dump (34KW) Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Photoinjector Design for 3 Cryomodules and No Building Extension Capture Cavity (1.3GHz) low energy spectrometer chicane (for bunch compression) quads dipole corr. quads dipole corr. Egun X X X X 1st cryomodule 9.9 meters BPM pair X instrumentation cross current monitor Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Bunch Compression (22.5° chicane) Egun: Peak acc. gradient=20MV/m, phase=-10° CC-1: Peak acc. gradient=16MV/m, phase=-37.5° Before Chicane: RMS bunch length =2.40 mm After Chicane: RMS bunch length =.34 mm Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Comments on Reduced Photoinjector • Limitations: • No space for 3rd harmonic cavity – “banana” shape in longitudinal phase space – how does one interpret cavity measurements under these conditions? Can’t quite get 300 micron bunch length. • off-axis beamline does not have tuneable R56 (as in the full photoinjector design) – not suitable for ILC crab cavity testing • large momentum spread – very difficult to control beam size (maybe impossible) • Low energy (KE=18.2 MeV) – space charge may additionally blow up beam • No room for additional experiments • Minimal space for instrumentation and correctors – not sure we have enough • No flat beam transform • CC-1 not suitable (can only get peak acc. gradient=12MV/m); must use CC-2 Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church
Outlook • Moving the photoinjector from A0 to NML will provide opportunities for upgrades to permit full beam testing of 1-2 ILC cryomodules • The new photoinjector will provide opportunities to fully test ILC crab cavities • However, the space constraints put on the photoinjector after the addition of the 3rd cryomodule without a building extension make the photoinjector unsuitable for full beam testing of ILC cryomodules or crab cavities Migration of Photoinjector to NML AAC Review 12/5/06 – M. Church