MICE Beam Loss vs Particle Rate

Adam Dobbs, ISIS Meeting, 18th December 2009

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Outline Current Beamline Analysis Procedure Latest High Beam Loss (~5V) results Future Plans

18/12/2009A Dobbs

3

Current MICE beamline

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Target

Q1-3

D1 D2 Q4-6 Q7-9

DS

CKOV A, BGVA1

BM1 TOF0

BM2

TOF1

D = Dipole bending magnet Q = Quadrupole magnetDS = Decay solenoid DSA = Decay Solenoid Are a GVA1 = Scintillator counter CKOV = Cherenkov detector BM = Beam Profile Monitor TOF = Time of Flight

ISIS

DSA MICE Hall

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Beam Loss vs Particle Rate Flow Diagram

18/12/2009A Dobbs

Target DAQ data DATE DAQ data

Data Reduction 1 – fitted peak beam loss analysis, etc

Particle rate data extraction with ScalersAnalysis

Reduced Beam Loss data

Particle 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

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Results

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

GVA1 vs Sector 7 Fit Beam Loss

Magnitude of Sector 7 Fit Beam Loss (V)

Avera

ge G

VA

1 d

uri

ng s

pill gate

(co

unts

/ s

ec)

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One point = the mean values of the beam loss and particle rate for a run

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0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

1,600,000

1,800,000

BPM1 vs Sector 7 Fit Beam Loss

Magnitude of Sector 7 Fit Beam Loss (V)

Ave

rage

BPM

1 du

ring

spi

ll ga

te (c

ount

s /

sec)

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0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

200,000

400,000

600,000

800,000

1,000,000

1,200,000

BPM2 vs Sector 7 Fit Beam Loss

Magnitude of Sector 7 Fit Beam Loss (V)

Ave

rage

BPM

2 du

ring

spi

ll ga

te (c

ount

s /

sec)

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Future Plans

18/12/2009A Dobbs

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

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Preliminary ToF Data for Run 1231

18/12/2009A Dobbs

Produced using G4MICE/TofMonitor

e µ π

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Analysis Procedure Step I.I – Beam Loss

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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

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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

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DATE DAQ data

Particle Rate data

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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

18/12/2009A Dobbs

Reduced Beam Loss data Particle Rate data

Combined data (ROOT files)

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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

18/12/2009A Dobbs

Combined data (ROOT

files)

Final plots of beam loss vs particle rate

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Histogramme of GVA1 rate per target dip, for run 1231

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One of the better fits!