preliminary nml radiabeam transverse profile monitor initial testing at a0 alex lumpkin bob flora...
TRANSCRIPT
Preliminary
NMLNML RadiaBeam RadiaBeamTransverse Profile Transverse Profile
MonitorMonitor Initial Testing Initial Testing at at A0A0
Alex Lumpkin Bob Flora Congcong Tan James Santucci Jinhao Ruan Randy Thurman-Keup Yin-e Sun
Brad Tennis Elias Lopez Ryan Montiel
Dallas Heikkinen Jim Fitzgerald Jim Galloway John Seraphin
2010 September 29
Bob Goodwin Mike Kucera
Ce:YAGCe:YAG
OTROTR
Virtual Virtual TargetTarget
Zoom Zoom LensLens
CameraCameraActuatorActuator
MirrorsMirrorsFilter Filter WheelWheel
The “A0 RadiaBeam” project objective is to evaluate transverse beam profile monitors proposed for the NML Low Energy Beamlines. A0 was simply chosen as a convenient test bed and RadiaBeam was chosen on the merits of their modular IBIS (Integrated Beam Imaging System) design proposal. Thin metallic foil screens for Optical Transition Radiation (OTR) and Ce:YAG single‐crystal scintillators are being investigated along with all supporting mechanical, electronic, and optical systems. The project goal is to move from prototype evaluation into production for NML.
16 16 lines/mmlines/mm
Reference
Black
WhiteWhite
48%48% modulatiomodulatio
nn
fully zoomed out 18x18 mm field ‐of view, resolution in excess of 15
line pairs per mm(at 20% contrast)
Resolution:Resolution:σ =14 µmσ =14 µm
29 29 lines/mmlines/mm
Reference
Black
WhiteWhite
50%50% modulatiomodulatio
nn
Resolution:Resolution:σ = 7 µmσ = 7 µm
Zoom to 5 mm
Zoom Zoom efficiencefficiency = 58%y = 58%
Virtual Target
15 mm
LEDLED
LEDLED
YAG YAG ScreenScreen
YAG YAG ScreenScreen
CameraCamera
Virtual Virtual TargetTarget
Virtual Virtual TargetTarget
LEDLED
Virtual Virtual TargetTarget
CameraCamera
Z matchedZ matched
First Light
10 bunches on YAG
Bea
mBea
m
Dark
Curr
ent
Dark
Curr
ent
YAG edge
YAG edge
Small Round Beam
242 µm242 µm
100 pC on YAG100 pC on YAG
Narrow Beam Stripe
131 µm131 µm
100 pC on YAG100 pC on YAG
Short Flat Beam
60x96 µm60x96 µm
20 pC on YAG20 pC on YAG
ZOOM
1 mm1 mm197 pix197 pix
oror5.08 µm/pix5.08 µm/pix
Zoom In
46 µm46 µm
Low Charge
We easily measured single
bunch beams less than 15 pC15 pC
with sigma widthsof ~50 µm.
Repeatability (with beam)
• 5 withOUT actuation: ~±2 pixels
• 5 WITH actuation: ~±2 pixels
2 sets of 5 measurements
need to make more
measurements just using the LED illumination
Conclusion
•What we DID measure:• 46 µm46 µm sigma beam
• 15 pC15 pC single bunch
•What we did NOT find:• the YAG saturationsaturation point
• the OTR meltingmelting point
Possible Improvements
• Replace Virtual Target with 4th position Calibration Target• Requires binary weighted actuators• Use annular LED to illuminate Calibration Target or fixed beam splitter with LED
• Zoom lens needs position read back for zoom, aperture, and focus.
• Eliminate bearing over-constraint (use gimbal bearings and relaxed clearance)
• needs to include solenoid & bracket mounted and wired with mounted connector.
• limit switches need to be calibrated and wired with mounted connector
• finger pinch shield needs to be broken up into 3 2π/3 pieces
• foils need to be delivered mounted and pre-baked.
• Vacuum cross and optical assembly need to be joined with a bolted flange.
• must include an integral ridged backbone
• each cross needs to be delivered as a completely assembled & functional package
BergozBergozIn-flange Integrating Current
Transformer
Unfiltered Signal
50 MHz Low Pass
250 MHzDigitizer
62 data points / bunch