1. Accelerator Physics and Engineering Update Jan 6, 2010
Josef Frisch
Tonee Smith
Clive Field
Alan Fisher
Henrik Loos
Christopher Behrens (NEW!)
Nate Lipkowitz (NEW!)
Jeff Rzepiela
Mark Petree
Steve Smith
Jim Welch
Glen White
Walter Wittmer
Mark Woodley
Gerald Yocky

2. APE: What we do Physics Engineering Operations
Whatever it takes to make accelerators work
Some long term planned projects
Some kludges to get systems working
E-beam optics
Light optics
X-rays
Detectors
Applications
Modeling RF
Electronics
Acoustics
Vacuum
Mechanical
PowerPoint

3. Beam Arrival Time Monitor Problem
Phase cavity difference noise has been increasing since October
Increase from 12 to ~50 femtoseconds RMS
Difficult to debug: still smaller than raw beam jitter, no signal when beam is off.
Not yet the dominant noise source, but will be soon!
In addition to short term fix, need an independent check: 3rd phase cavity?

4. Future Timing
Previous meeting mentioned using an optical / X-ray cross-correlator.
X-rays
Reflected optical beam measured on array sensor
Laser
GaAs or similar
Tests at SXR (W. Schlotter et al) have demonstrated 60fs RMS single shot X-ray to laser optical timing measurement.
Note that electronic timing will still be needed for “crude” 100fs timing

5. Cross Correlator (very preliminary)
(SXR)
M. Beye
B. Schlotter
W. Schlotter et al. (LCLS)

6. Materials Damage and Wavefront Distortion Tests
Fused Silica damages
Damage
Speckle from Be attenuators led to search for alternate materials
Damage and wave front distortion tests indicate that Al2O3, Diamond and SiC all are OK.
3D map of damage to SiO2 Sample

7. Be Lens to be Installed in LCLS X-ray diagnostics chamber
Reduce divergence to (incorrect) design
B. Lenegeler, J. Krzywinski, E. Kraft, et al. (Engineering, LCLS, APE, etc)

8. Broadband IR Spectrometer for Bunch Length Measurement
Measure spectrum of OTR light from short bunches to estimate bunch length
Need single shot, very broadband ~50:1 low resolution (25%) spectrometer
Operating range ~0.8 –40 microns
Optics design done, prototype parts on order
Parabolic
mirror
Prism,
KRS-5
Tilted image plane corrects aberrations
OTR
foil
Christoph Behrens
Henrik Loos
Jennifer Loos
Sasha Gilevich
Pyroelectric
Array detector
Parabolic
mirror

9. THz Emitted THz power GaAs z-scan
THz system for LCLS now being commissioned.
Working with Pulse, and Stanford have first demonstration experiments with THz
Alan Fisher will discuss in detail in next talk.
Emitted THz power
GaAs z-scan
D. Daranciang et. Al.

10. LHC Synchrotron Light Monitor
Lead Ions at 2.3 TeV
A. Fisher will discuss in next talk

11. ATF2 Recent Results
4 OTR screens now provide reproducible emittance measurements in less than a minute, rather than hours for the wire scanners (1.5 Hz beam).
25 Cavity BPMs now working at <50nm resolution
Spot size monitor not working in high resolution mode (ATF2 group)
Automated Dispersion Correction
G. White, M. Woodley, S. Boogert, T. Smith

12. Other Projects 120Hz upgrades FACET bunch length monitors
Time-slot aware feedbacks: Big project from Controls and APE.
Accelerator now at 120Hz with good time-slot.
FACET bunch length monitors
(similar to LCLS)
Diagnostics and control applications
Ongoing efforts to automate machine operations
Thermal-acoustic X-ray calorimeter
Passed Vacuum check
Install in late January.