MICE Particle Rate and ISIS Beam Loss Adam Dobbs, Target – ISIS Meeting, 17 th September 2010

Outline I. Introduction I. Beamline II. Analysis Methodology III. Study Conditions II. Results I. November 2009 II. June 2010 III. August 2010 III. Conclusion 17/09/2010A Dobbs2

1. Introduction The MICE Beamline Analysis Methodology 17/09/2010A Dobbs3

Current MICE beamline 17/09/2010A Dobbs D = Dipole bending magnetQ = Quadrupole magnet CKOV = Cherenkov detectorKL = KLOE Light detector GVA1 = Scintillator counterTOF = Time of Flight BM = Beam Profile MonitorDS = Decay Solenoid DSA = Decay Solenoid Area LM = Luminosity Monitor Target ISIS Q1-3 D1 DS D2Q4-6 GVA1BM1CKOV A,B BM2 TOF0 Q7-9 DSA MICE Hall TOF1 TOF2KL LM 4

17/09/2010A Dobbs5 Target DAQ dataDATE DAQ data Data Reduction 1: integrated beam loss analysis, etc Particle rate data extraction with G4MICE Scalers app Reduced Beam Loss data Particle 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

Beam Loss Analysis Methods 17/09/2010 Peak Value Integral Value Target DAQ data Data Reduction 1 – fitted peak beam loss analysis, etc Reduced Beam Loss data A Dobbs6

17/09/2010A Dobbs Study Conditions 7

2. Results November th June th June 2010 August /09/2010A Dobbs8

Nov 09: Target Depth and S7 vs S8 17/09/2010A Dobbs9

17/09/2010A Dobbs Nov 09: Rate Vs. Beam Loss 10

June 10: Target Depth Vs. Beam Loss 17/09/2010A Dobbs11

June 10: Luminosity Vs. Beam Loss 17/09/2010A Dobbs12

June 10: Luminosity Vs. Beam Loss Spill-by-Spill 17/09/2010A Dobbs13

15 th & 16 th June10: Rate Detectors 17/09/2010A Dobbs14 15th study: 15 TOF1 hits per 3.2ms spill at 1.3V.ms 25 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.ms 60 TOF1 hits per 1ms spill at 2V.ms. NB: 1.3V.ms ~ 2V peak in R8BLM1

16 th June: TOF PID for Run /09/2010A Dobbs15  Large peak is mainly muons with perhaps some pion contamination in tail  Small peak to the left is positrons

15th study:Average # of pulses per run = 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 17/09/2010A Dobbs16 NB Removed run 2011 from 16th plot, bad reconstruction due to DAQ error 16th study:Average # of pulses per run = tracks per 1ms spill at 1.3V.ms 33.5 tracks per 1ms spill at 2V.ms → Reduction of ~ 60% for 15 th, ~ 40% for 16 th Possible causes include particle decay between TOF0 and TOF1 and DAQ deadtime.

Aug 10: Target Depth and S7 Vs S8 17/09/2010A Dobbs17

Aug 10: Rate Vs. Beam Loss 17/09/2010A Dobbs18 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).

3. Conclusion Summary Future Plans 17/09/2010A Dobbs19

Summary 17/09/2010A Dobbs  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 +ve NBRemember doublet optics, and losses due to reconstruction when interpreting this. 20

Future Plans 17/09/2010  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 A Dobbs21

Spares 17/09/2010A Dobbs22

Preliminary TOF Analysis 17/09/2010A Dobbs23