Transcript Document 7829066

Laser interferometric beam size monitor
(Shintake-monitor)
Taikan SUEHARA, ILC-Asia wg4 meeting @ KEK, 2005/9/21
Progress : Optics
• Actuators
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PMC-200-P Driver cannot be repaired.
Looking for substitution (existing products)
Manuals of PMC400 & 500 will be arrived this week
I found PMC-200-P in an auction website …
• Optical Table
– Waiting for estimate paper. (Meiritsu-Seiki)
• Sensors
– Found Photodiode used in laser table (with mount).
– It’s functional. Will perform some tests (linearity etc.)
Taikan SUEHARA, ILC-Asia wg4 meeting @ KEK, 2005/9/21
Laser & Control
• FFTB Laser
– SP person will come tomorrow.
• Control system
– Looking for VME CPU.
Taikan SUEHARA, ILC-Asia wg4 meeting @ KEK, 2005/9/21
Gamma detector
• Beam test site
– ATF
– TERAS-LCS @ AIST
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1~40 MeV gamma by Laser-Compton Scattering
Storage ring & CW Laser (ie. photons come continuously)
Maybe enough intensity in total
MEG group used it for beam test (3? years ago)
Taikan SUEHARA, ILC-Asia wg4 meeting @ KEK, 2005/9/21
Gamma detector (2)
• Strategy to reduce background
– Independent on conversion/creation statistics
• Multiple material
• Difference in position (x & y)
– Vulnerable on conversion/creation statistics
• Difference in position (beam axis)
• Laser On/Off subtraction
Taikan SUEHARA, ILC-Asia wg4 meeting @ KEK, 2005/9/21
Gamma detector (3)
• Subtraction by multiple material
– Absorber – gas – material layer
– Air : ~0.05 p.e./cm (β~1)
Low signal strength : much space required (~1m?)
– Must use gas of slightly lower n than air
for below-29MeV threshold.
– For material layer also cherenkov-material
(not scintillator) may be good.
(energy response may be different for scintillators)
– Light material is good.
(not to stop gamma outside absorber)
– Pb - gas(n<1.0003) - aerogel ?
Taikan SUEHARA, ILC-Asia wg4 meeting @ KEK, 2005/9/21
Plan
Taikan SUEHARA, ILC-Asia wg4 meeting @ KEK, 2005/9/21