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MICE Particle Rate and ISIS Beam Loss. Adam Dobbs, Target – ISIS Meeting, 17 th September 2010. Outline. Introduction Beamline Analysis Methodology Study Conditions Results November 2009 June 2010 August 2010 Conclusion. 1. Introduction. The MICE Beamline Analysis Methodology. - PowerPoint PPT Presentation
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MICE Particle Rate and ISIS Beam Loss
Adam Dobbs, Target – ISIS Meeting, 17th September 2010
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OutlineI. Introduction
I. BeamlineII. Analysis MethodologyIII. Study Conditions
II. ResultsI. November 2009 II. June 2010III. August 2010
III. Conclusion
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1. Introduction
The MICE BeamlineAnalysis Methodology
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Current MICE beamline
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D = Dipole bending magnet Q = Quadrupole magnetCKOV = Cherenkov detector KL = KLOE Light detector GVA1 = Scintillator counter TOF = Time of FlightBM = Beam Profile Monitor DS = Decay SolenoidDSA = Decay Solenoid Area LM = Luminosity Monitor
Target
ISIS Q1-3
D1
DS
D2 Q4-6
GVA1 BM1 CKOV A,B
BM2
TOF0
Q7-9
DSA
MICE Hall
TOF1
TOF2 KL
LM
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Target DAQ data
DATE DAQ data
Data Reduction 1: integrated beam loss analysis, etc
Particle rate data extraction with G4MICE Scalers app
Reduced Beam Loss
dataParticle Rate
data
Combine data by matching time stamps
Combined data
Data reduction 2: extract means and errors for variables on a run-by-run basis (throw away spill-by-spill correlation)
Final plots of beam loss vs particle rate
gzipped ascii, sorted by time
binary, sorted by run
ascii, sorted by time
ascii, sorted by run
ROOT binary, sorted by run
ROOT binary, sorted by study
Time-of-Flight data
Time-of-Flight data extraction with G4MICE TofTree app
Apply cuts to find physical tracks and extract number present
Reconstructed TOF track data
Use Sector 7 Integrated Beam Loss per run
Final plots of beam loss vs reconstructed
tracks
ROOT binary, sorted by study
Match beam loss and TOF track data by run number
ROOT binary, sorted by study
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Beam Loss Analysis Methods
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Peak Value
Integral Value
Target DAQ data
Data Reduction 1 – fitted peak beam loss analysis, etc
Reduced Beam Loss data
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Study Conditions
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2. Results
November 2009 15th June 201016th June 2010
August 2010
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Nov 09: Target Depth and S7 vs S8
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Nov 09: Rate Vs. Beam Loss
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June 10: Target Depth Vs. Beam Loss
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June 10: Luminosity Vs. Beam Loss
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June 10: Luminosity Vs. Beam Loss Spill-by-Spill
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15th & 16th June10: Rate Detectors
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15th study: 15 TOF1 hits per 3.2ms spill at 1.3V.ms25 TOF1 hits per 3.2ms spill at 2V.ms
Assuming linearity of rate across the spill:
5 TOF1 hits per 1 ms spill at 1.3V.ms 8 TOF1 hits per 1ms spill at 2V.ms. 1
16th study: 30 TOF1 hits per 1ms spill at 1.3V.ms60 TOF1 hits per 1ms spill at 2V.ms.
NB: 1.3V.ms ~ 2V peak in R8BLM1
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16th June: TOF PID for Run 2004
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Large peak is mainly muons with perhaps some pion contamination in tail
Small peak to the left is positrons
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15th study: Average # of pulses per run = 426 6.5 tracks per 3.2ms spill at 1.3V.ms
10.5 tracks per 3.2ms spill at 2V.ms
Assuming linearity of rate across the spill:
2 tracks per 1 ms spill at 1.3V.ms 3 tracks per 1ms spill at 2V.ms.
Reconstructed TOF Tracks Vs. Beam Loss
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NB Removed run 2011 from 16th plot, bad reconstruction due to DAQ error
16th study: Average # of pulses per run = 36122 tracks per 1ms spill at 1.3V.ms33.5 tracks per 1ms spill at 2V.ms
→ Reduction of ~ 60% for 15th, ~ 40% for 16th
Possible causes include particle decay between TOF0 and TOF1 and DAQ deadtime.
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Aug 10: Target Depth and S7 Vs S8
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Aug 10: Rate Vs. Beam Loss
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DATE DAQ Gate short and late wrt to spill → target parabola swinging later in spill as depth increases could cause observed non – linear rate increase with beam loss.
Tail off at the end of TOF Tracks plot probably caused by DAQ deadtime or software reconstruction inefficiency (although number of particles in whole spill gate is not high, very large beam losses do lead to very large instantaneous rates).
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3. Conclusion
SummaryFuture Plans
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Summary
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Beam Loss varies approximately linearly with target BCD for 25mm ≤ BCD ≤ 30mm, for ‘normal’ short target delay
Particle Rate in the MICE Beamline scales approximately linearly with increasing Beam Loss up to 5V.ms in (Sector 7 Integral)
At 2V beam loss for π → µ optics observed: 8 TOF1 hits per 1ms spill for –ve 60 TOF1 hits per 1ms spill for +veNB Remember doublet optics, and losses due
to reconstruction when interpreting this.
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Future Plans
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No more data runs planned in nearer future TOF reconstruction – understand why seem to
lose particles c.f. Scalers Model beam line rates with G4BeamLine /
G4MICE simulations Use ORBIT to understand loss patterns around
ISIS and relate beam loss to protons-on-target
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Spares
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Preliminary TOF Analysis
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