Proton Calorimetry/Meetings/2016/11/02

Minutes for UCL Proton Calorimetry Meeting, 5th November 2016 (D17, Physics & Astronomy, UCL)

Present

Simon Jolly, Ruben Saakyan, Laurent Kelleter, Andreas Christou, Matthieu Hentz, Adam Knoetze

RS:

• Dates for next Clatterbridge run set: 24th/25th November.
• Planning for next run:
  • Same measurements as last run but with our divider rather than Hamamatsu active divider:
    • Our divider contains no active components (transistors etc.) to linearise response of PMT: may be reason for high rate distortion.
    • Additional capacitive resistance in active divider means higher resistance for high rates.
  • Measure high rate and linearity: retake wheel measurement.
  • Record Caen ADC, Caen waveform and scope waveform.
  • Take both scintillator blocks: start with new block, try old block if we have time.
• Check with Anastasia about potential questions for next run.

AK:

• Converted all data from LeCroy scope format on plus1.
• Can’t easily find peaks as all waveforms concatenated together with continuous timebase.
• Looking at ROOT, Geant4 tutorials and detector emulator manual.
• Will start looking at producing periodic pulses from detector emulator.
• Aim is to produce replica of PMT output signal for proton light pulse with realistic noise variation.

MH:

• Looking at energy deposition with proton pencil beam tutorials on PBT Wiki.
• Comparing energy deposition in scintillator and water: seeing nice Bragg Peaks!
• Will redo simulations using 60MeV pencil beam and check match to Clatterbridge data. Also replot with finer energy and position resolution.
• Next step is to start integrating Clatterbridge beamline simulation and characterise the effect of adding in each component.

AC:

• Looking at improving fitting of Caen ADC spectrum.
• Improved quality of fit by increasing convolution number: reduces Chi2 by about half, but doubles time to produce fit.
• Newer fit works over larger range, improving errors on fit, but results in slightly larger energy resolution.
• Will look at other spectra before moving onto waveform data.

LK:

• Running simulations in Geant4 of segmented calorimeter.
• Reading out photon production for individual scintillator slices in response to single protons.
• Seeing both Bragg Peak and effects of quenching!
• Possible bug in Geant4: total energy deposition in scintillator + wrapping more than initial energy.
• Will fix scintillator and wrapping thickness and add more layers for higher energy.

SJ:

• Date of next visit to Clatterbridge fixed for 24th/25th November.
• Have heard back from Liviu Penescu at MedAustron: still waiting on possible dates to visit for experimental runs. Liviu to confirm availability of collimators and mounting.
• Also need to arrange PSI visit: Ros Perrin/Tony Lomax lung phantom with UCL scintillator.
• Requested that future talks uploaded to wikiData presentations directory contain some description of the data they show and include useful info in filename.