MICE Beam Loss vs Particle Rate Adam Dobbs, ISIS Meeting, 18 th December 2009

Outline  Current Beamline  Analysis Procedure  Latest High Beam Loss (~5V) results  Future Plans 18/12/20092A Dobbs

Current MICE beamline 18/12/2009A Dobbs3 Target Q1-3 D1D2Q4-6Q7-9 DS CKOV A, BGVA1BM1TOF0 BM2 TOF1 D = Dipole bending magnet Q = Quadrupole magnet DS = Decay solenoid DSA = Decay Solenoid Area GVA1 = Scintillator counter CKOV = Cherenkov detector BM = Beam Profile Monitor TOF = Time of Flight ISIS DSA MICE Hall

Beam Loss vs Particle Rate Flow Diagram 18/12/2009A Dobbs4 Target DAQ dataDATE DAQ data Data Reduction 1 – fitted peak beam loss analysis, etc Particle rate data extraction with ScalersAnalysis Reduced Beam Loss dataParticle Rate data Combine data by matching time stamps Combined data (ROOT files) Data reduction 2: extract means and sigmas for variables on a run-by-run basis Final plots of beam loss vs particle rate

Results 18/12/20095A Dobbs One point = the mean values of the beam loss and particle rate for a run

18/12/20096A Dobbs

18/12/20097A Dobbs

Future Plans 18/12/2009A Dobbs8  Another high beam loss study planned for December machine physics period  Reproducibility  Better statistics (400 – 500 pulses per setting)  Use ToF data  Another rate counter  PID  Compare with G4BeamLine simulations

Preliminary ToF Data for Run /12/2009A Dobbs9  Produced using G4MICE/TofMonitor e µ π

Analysis Procedure Step I.I – Beam Loss 18/12/200910A Dobbs  Initially for each target dip a whole spectrum of data is present for each variable (black sample spectra shown above). Canonical single values for each variable are calculated from the spectra using BLA Part 2 to given one value for each variable per target dip (fits doing this shown in red). These are written to an ascii file. Target DAQ data Reduced Beam Loss data

Analysis Procedure Step I.II - Particle Rate  Held in DATE data stream i.e. in binary  Contains GVA1, BM1, BM2, various TOF0 and TOF1 data  Extracted using a modified version of G4MICE ScalersAnalysis application  Output is an ascii file containing the number of hits for each detector per spill (i.e. per target dip)  TOF data harder to interpret 18/12/200911A Dobbs DATE DAQ data Particle Rate data

Analysis Procedure Step II - Combine the data  Once the beam loss and particle rate data has been converted to ascii files containing values for each target dip, the data from the two streams must be combined  Data are synchronised using timestamps associated with each target dip data set (the clocks of the two DAQs are synched)  -> Leads to combined data set holding both beam loss and particle rate data per target dip 18/12/200912A Dobbs Reduced Beam Loss data Particle Rate data Combined data (ROOT files)

Analysis Procedure Step III - extract mean values per run and plot  A combined data file is produced for each run  This file is processed using ROOT to calculate the mean and sigma of each value for a run (a second data reduction) e.g. the mean of GVA1, the mean summed beam loss in sector 7  The values are finally plotted for a series of runs, each having a different nominal beam loss value, but with all other parameters (e.g. Optics) held constant 18/12/200913A Dobbs Combined data (ROOT files) Final plots of beam loss vs particle rate

Histogramme of GVA1 rate per target dip, for run /12/200914A Dobbs One of the better fits!