discussion session carsten hast, mauro pivi slac
TRANSCRIPT
Andy WhiteUniversity of Texas at Arlington
For GEM DHCAL GroupESTB Workshop SLAC 2012
• Introduction• KPiX Readout• FTBF Beam Test Setup• Beam Test Analysis Results• Large Chamber Development• GEM DHCAL Plans + Test beam needs
7GEM DHCAL A. White
Application of Large Scale Gas Electron Multiplier Technology
to Digital Hadron Calorimetry
Toward 100cmx100cm GEM Planes!!
GEM DHCAL A.White 8
Two 33cmx100cm chamber parts delivered
Class 10,000 clean room (12’x8’) construction completed
Jig for 33cmx100cm chamber being procured
Assembly jig
Anode
Spacer
GEM Foil
Positioners
Positioners
Parameters required for Beam Tests
Beam parameters Value Comments
Particle Type e- would positrons be ok? Yes
Energy (2-13 GeV) Any ?
Rep Rate (1-5 Hz nominal,Bursts up to 120 Hz)
Can use up to 120 Hz
Charge per pulse or number of electrons/pulse
1 e-/pulse How short is a pulse? Interval?
Energy Spread Not critical
Bunch length r.m.s. ?
Beam spot size, x-y, emittance x x y ~ 0.5 x 0.5 cm2 or smaller
Others (cooling water, gasses, etc.) Ar CO2 80:20
Logistics RequirementsSpace requirements (H x W x L) 6x6x10 ft3)Others (cooling water, gasses, electricity, etc.) Ar CO2 80:20Duration of Test and Shift Utilization 2 x 2 weeks
Desired Calendar Dates Spring, Fall 2013
To the presenter at the ESTB 2012 Workshop: please, fill in/update the table (at best) with the important parameters needed for your tests
Plans for Radiation Damage Studies for Si Diode Sensors
Subject to 1 GRaD Doses
Bruce SchummSLAC Testbeam WorkshopAugust 23 2012
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The Issue: ILC BeamCal Radiation ExposureILC BeamCal:
Covers between 5 and 40 miliradians
Radiation doses up to 100 MRad per year
Radiation initiated by electromagnetic particles (most extant studies for hadron –induced)
EM particles do little damage; might damage be come from small hadronic component of shower?
Bruce Schumm
SUMMARY
ILC BeamCal demands materials hardened for unprecedented levels of electromagnetic-induced radiation
10-year doses will approach 1 GRad.
Not clear if hadrons in EM shower will play significant role need to explore this
At 1 nA, 1 GRad takes a long time (60 hours); multiply time ~10 samples really long time• More beam current (?)• Start with 100 MRad studies (already interesting)
Bruce Schumm
Parameters required for Beam Tests
Beam parameters Value Comments
Particle Type e- Positrons would be fine
Energy (2-13 GeV) Maximum
Rep Rate (1-5 Hz nominal,Bursts up to 120 Hz)
Maximum As long as we can figure out how to handle 500W
Charge per pulse or number of electrons/pulse
Maximum
Energy Spread Not a concern
Bunch length r.m.s. Not a concern
Beam spot size, x-y, emittance Less than ~1mm Rastering would be very helpful!
Others (cooling water, gasses, etc.) Rastering, cooling (W or Pb?) Tungsten for target? (Otherwise Pb)
Logistics Requirements
Space requirements (H x W x L) 1m x 1m x 1m (plus 20cm x 20cm x 20cm 1-2 m upstream)
Others (cooling water, gasses, electricity, etc.) Need to figure out how to cool 500W
Duration of Test and Shift Utilization About 1 week; perhaps no owl? Whatever we could get really.
Desired Calendar Dates Winter 2013
To the presenter at the ESTB 2012 Workshop: please, fill in/update the table (at best) with the important parameters needed for your tests
Bruce Schumm
Digital Hadron Calorimeter (DHCAL) Tests
• Development of low-resistivity glass is underway in collaboration with the COE College, Cedar Rapids, Iowa.
• Might need to test RPCs with different glass samples in beam.• Variable particle rate over 50 – 2000 Hz/cm2 is needed.
Secondary Emission (SE) Calorimetry Tests
• In an SE detector module, secondary electrons are generated from an SE cathode when charged hadron or electromagnetic shower particles penetrate the SE sampling module placed between absorber materials in calorimeters.
• A prototype SE module is being built with alternating layers of multianode PMT arrays and steel absorbers (first stage involves testing a single layer with an absorber of variable thickness).
Dual Readout/Crystal Calorimetry
• Different crystal samples with different readouts.• Test for the time and spatial development of scintillation and Čerenkov light.• Readout with SiPMs and PMTs directly coupled to the crystals.• Test for different crystal properties (surface finish, wrapping, etc.)• Precise beam position measurement is needed (wire chambers, etc.)
Parameters required for Beam Tests
Beam parameters Value Comments
Particle Type e- would positrons be ok? - Yes
Energy (2-13 GeV) 2-13 GeV Stage II hadrons??
Rep Rate (1-5 Hz nominal,Bursts up to 120 Hz)
Charge per pulse or number of electrons/pulse
Low rate: 50-400 electrons/pulse @ 1HzHigh rate: 50K electrons/pulse @ 1 Hz
Energy Spread <0.1%
Bunch length r.m.s.
Beam spot size, x-y, emittance Would need position detectors (wire chambers, …)
Others (cooling water, gasses, etc.)
Logistics Requirements
Space requirements (H x W x L) 1x1x1 m3 – 5x5x5 m3
Others (cooling water, gasses, electricity, etc.)
Duration of Test and Shift Utilization 1 week, 2-3 8-hour shifts/day
Desired Calendar Dates Flexible about schedule depending on beam availability
Introduction to FACET
• FACET uses 2/3 SLAC linac to deliver
electrons to the experimental area in Sector
20
• The FACET dump separates FACET from
LCLS
• Our first User Run was April-July 2012
http://facet.slac.stanford.edu
Facility for Advanced Accelerator Experimental Tests
41
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Beam Parameters
Parameter Typical Value 2012 Best Value 2012
Energy (GeV) 20.35
Charge per pulse 2.7 nC (1.7e10 e-) 3.0 nC (2.0e10 e-)
Bunch length σz (μm) 20-25 20
Beam size σx x σy (μm)
35 x 35 20 x 23
Particle Electrons
Positrons will be commissioned in 2013 for delivery to experiments in sector 20 in 2014.
E-200 Multi-GeV Plasma Wakefield Acceleration
• SLAC, UCLA, MPI
• FACET’s high power electron beam ionises alkali gas and interacts
with the plasma, wakefields accelerating part of the bunch
• Lithium – small interaction, occasionally significant acceleration
observed
• Rubidium - consistently lots of interaction and good acceleration
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Beam bypassing plasma Beam going through plasma
Significant interaction (energy loss)
Energy gain by ~8% of beam
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Looking Ahead…
• FACET’s second User run is in winter/spring 2013- Proposals for 2013 and 2014 currently welcome!
https://slacportal.slac.stanford.edu/sites/ard_public/facet/user/Pages/ProposalOverview.aspx
- The proposal deadline is 1st September
- FACET User Meeting 9th/10th October
http://www-conf.slac.stanford.edu/facetusers/2012/
- Next SAREC review 11th/12th October
• New features to the facility are coming:- E-200 is installing a 10TW Laser to pre-ionise plasma
- Positrons will be commissioned in 2013 for delivery to experiments in 2014
- Designs for a THz transport line are in place to take THz up to the laser
room
• FACET continues to run ~4 months/year until 2016