Proton Calorimetry/Meetings/2017/03/08

Minutes for UCL Proton Calorimetry Meeting, 8th March 2017 (D17, Physics & Astronomy, UCL)

Present

Simon Jolly, Ruben Saakyan, Anastasia Basharina-Freshville, Laurent Kelleter, Adam Knoetze, Matthieu Hentz, Andreas Christou, Jordan Silverman

AC:

• Working on waveform fitting in ROOT:
  • Gaussian part of the fit works.
  • Trying to fit falling edge of pulse using single exponential.
  • Will try implementing double exponential.
• Can already filter out pulses with more than one peak:
  • Will reconstruct ADC spectrum from filtered waveforms.
  • Will vary integration window for pulse (50, 100, 150ns used in experiment).

MH:

• Looking at emittance and beam profile evolution along Clatterbridge beamline.
• Ignoring protons that fall outside the measurement region in simulations.
• Need to check initial parameters and beam density distributions: will plot intensity distributions to make it clearer.
• Updated geometry based on information from Andrzej's.

AK:

• Looking at Hamamatsu PMT response to LED.

ABF:

• Testing LED pulser to check whether variation in gain comes from LED or PMT.
• After MedAustron will retest with super-stable SuperNEMO LEDs.
• Taking signal from last dynode rather than anode to avoid final gain stage (~3.5) and saturation.
• Long scintillator bars arrived from Nuvia:
  • Wrapped in mylar only to reduce amount of internal reflections.
  • Energy resolution worse: ~11% at 1MeV.
• Preparing for MedAustron: MH and LK will prepare cables...
• Housing needs modifying to fit long scintillator bar: need to make sure its light tight in case room lights cannot be switched off. LK suggests using a cardboard box...

LK:

• Fitting curve to photon yield to check Bragg curve.
• Fit not yet perfect: still using an approximation.