Linac Diagnostics Commissioning Experience LCLS DOE Review July

LCLS Diagnostics Tasks Charge Bunch length Toroids (Gun, Inj, BC, Und) Faraday cups (Gun

Diagnostics Overview OTR screens (7) YAG screens (7) Wire scanners (7) Dipole magnets (8)

Beam Position and Charge Monitors 21 BPMs functional BPM polarity and scale checked with

BPM Position and Charge Online Display July 10, 2007 LCLS DOE Review 5 Henrik

BPM Resolution Test Synchronous acquisition of all BPM positions Fit of one BPM position

Charge Calibration First toroid and FC after gun not functional Use FC in gun

Wire Scanners 7 wire scanners installed 5 photo-multipliers and 4 ion chambers working EPICS

Wire Scanner Data Correction No Correction Charge & Jitter Correction July 10, 2007 LCLS

Wire Scanner Status All wire scanners are working WS orientation and calibration cross-checked with

OTR Screen Calibration Test Screen calibration agrees within 2. 5% with prediction from corrector

OTR Screen vs. Wire Scanner Same beam size from WS and OTR Beam shape

Transverse Deflecting Cavity Software for automated time scale calibration and bunch length measurement July

Bunch Length Monitors BL 12 – Ceramic Gap BL 11 – Coherent Edge Radiation

Bunch Length Monitors Both bunch length monitors installed Signal from wave guide diodes and

High Level Applications - Emittance Methods Multi screen Quad scan Devices OTR Wire scanner

High Level Applications – Correlation Plot Purpose Measure accelerator parameters vs. settings Use EPICS

Summary Most of the diagnostics is installed and commissioned Diagnostics is integrated into control

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Linac Diagnostics Commissioning Experience LCLS DOE Review July 11, 2007 Henrik Loos, for the LCLS Commissioning Team • Diagnostics overview • BPMs, Toroids, FCs • Wire Scanners • YAG/OTR Profile Monitors • Transverse Cavity • Bunch Length Monitors July 10, 2007 LCLS DOE Review 1 Henrik Loos, et al. loos@slac. stanford. edu

LCLS Diagnostics Tasks Charge Bunch length Toroids (Gun, Inj, BC, Und) Faraday cups (Gun & Inj) Transverse cavity + OTR (Inj, Linac) Coherent radiation power (BC) Trajectory & energy Stripline BPMs (Gun, Inj, Linac) Profile monitors (Inj), compare position with alignment laser Slice measurements Horizontal emittance T-cavity + quad + OTR Vertical Emittance Transverse emittance & energy spread Wire scanners YAG screen (Gun, Inj) OTR screens (Inj, Linac) July 10, 2007 LCLS DOE Review OTR in dispersive beam line + quad Energy spread T-cavity + OTR in dispersive beam line 2 Henrik Loos, et al. loos@slac. stanford. edu

Diagnostics Overview OTR screens (7) YAG screens (7) Wire scanners (7) Dipole magnets (8) Beam stoppers (2) S-band RF acc. sections (5) RF Gun Solenoid Gun Spectrometer RF Deflector X-band RF acc. section July 10, 2007 LCLS DOE Review 3 BC 1 Henrik Loos, et al. loos@slac. stanford. edu

Beam Position and Charge Monitors 21 BPMs functional BPM polarity and scale checked with correctors and model 5 current monitors and 1 Faraday cup operational EPICS Displays July 10, 2007 LCLS DOE Review 4 Henrik Loos, et al. loos@slac. stanford. edu

BPM Position and Charge Online Display July 10, 2007 LCLS DOE Review 5 Henrik Loos, et al. loos@slac. stanford. edu

BPM Resolution Test Synchronous acquisition of all BPM positions Fit of one BPM position vs. position calculated from all others Specification < 10μm Typical < 5μm July 10, 2007 LCLS DOE Review 6 Henrik Loos, et al. loos@slac. stanford. edu

Charge Calibration First toroid and FC after gun not functional Use FC in gun spectrometer to calibrate sum signal from first BPM July 10, 2007 LCLS DOE Review 7 Henrik Loos, et al. loos@slac. stanford. edu

Wire Scanners 7 wire scanners installed 5 photo-multipliers and 4 ion chambers working EPICS Displays July 10, 2007 LCLS DOE Review 8 Henrik Loos, et al. loos@slac. stanford. edu

Wire Scanner User Interface Raw Synchronized Data PMT, Toroid, BPM Selection Processed Profile July 10, 2007 LCLS DOE Review 9 Henrik Loos, et al. loos@slac. stanford. edu

Wire Scanner Data Correction No Correction Charge & Jitter Correction July 10, 2007 LCLS DOE Review 10 Henrik Loos, et al. loos@slac. stanford. edu

Wire Scanner Status All wire scanners are working WS orientation and calibration cross-checked with correctors, BPMs and OTRs Some wire cards rotated, fixed in software Charge and jitter correction commissioned PMT/Ion chambers need work Some WS give weak signals on PMTs Ion chambers close to TD 11 dump saturate and have large background July 10, 2007 LCLS DOE Review 11 Henrik Loos, et al. loos@slac. stanford. edu

YAG/OTR Profile Monitors 7 YAG and 7 OTR screens installed 14 optics boxes commissioned Control for screen insertion, 2 neutral density filters, screen and reticle illumination functional EPICS Displays July 10, 2007 LCLS DOE Review 12 Henrik Loos, et al. loos@slac. stanford. edu

Profile Monitor Calibration Measure known diameter of YAG crystal on CCD image Verify calibration of reticle image Use reticle for calibration if screen edge outside FOV July 10, 2007 LCLS DOE Review 13 Henrik Loos, et al. loos@slac. stanford. edu

OTR Screen Calibration Test Screen calibration agrees within 2. 5% with prediction from corrector scan and model July 10, 2007 LCLS DOE Review 14 Best focus close to screen center Constant beam size within +- 1 mm Henrik Loos, et al. loos@slac. stanford. edu

OTR Screen vs. Wire Scanner Same beam size from WS and OTR Beam shape shows good agreement Gaussian Fits July 10, 2007 LCLS DOE Review 15 Henrik Loos, et al. loos@slac. stanford. edu

Coherent Optical Transition Radiation Gaussian profile from WS Fluctuating profile from OTR with compressed beam July 10, 2007 LCLS DOE Review 16 OTR screen not usable for emittance measurement of highly compressed beam Henrik Loos, et al. loos@slac. stanford. edu

Transverse Deflecting Cavity Software for automated time scale calibration and bunch length measurement July 10, 2007 LCLS DOE Review 17 Henrik Loos, et al. loos@slac. stanford. edu

Bunch Length Monitors BL 12 – Ceramic Gap BL 11 – Coherent Edge Radiation Ceramic Gap Waveguide GHz Diode Detectors July 10, 2007 LCLS DOE Review 18 Henrik Loos, et al. loos@slac. stanford. edu

Bunch Length Monitors Both bunch length monitors installed Signal from wave guide diodes and pyroelectric detectors available All signals show strong correlation with accelerator phase and bunch compression Absolute calibration with TCAV in S 29 to be done Edge Radiation Monitor Ceramic Gap Monitor 100 GHz Diode 300 GHz Diode July 10, 2007 LCLS DOE Review 19 Henrik Loos, et al. loos@slac. stanford. edu

High Level Applications - Emittance Methods Multi screen Quad scan Devices OTR Wire scanner Features Scans automatic & manual Data & config files 1 button -> logbook Average & raw data Phase space plot Slice emittance July 10, 2007 LCLS DOE Review 20 Henrik Loos, et al. loos@slac. stanford. edu

High Level Applications – Correlation Plot Purpose Measure accelerator parameters vs. settings Use EPICS and results from HLA Features Scans 1 or 2 control variables Reads any process variable plus OTR/YAG screens Wire scan Emittance Synchronous acquisition 2 D data plots Different fit options July 10, 2007 LCLS DOE Review 21 Henrik Loos, et al. loos@slac. stanford. edu

Summary Most of the diagnostics is installed and commissioned Diagnostics is integrated into control system and being used by high level applications Bunch length monitors need more commissioning Some diagnostics in gun region (YAG, FC, IM) needs work in next down time Observation of coherent phenomena on OTR for ultra-short bunches: Future problems for OTR beyond BC 2? July 10, 2007 LCLS DOE Review 22 Henrik Loos, et al. loos@slac. stanford. edu