Proton Calorimetry/Meetings/2020/05/06

Minutes for UCL Proton Calorimetry Meetings, 6th May (Everyone is working from home)

Simon Jolly,Laurent Kelleter, Saad Shaikh, Raffaella radogna

As an exercise, both for practicing with the new version of the analysis code and for testing new possibilities, implemented a fitting method to fit a proton PDL distribution abusing of the Birks law as follows: dLdx = S/((dose)^-1 +kB)
- fitted G4 simulated data and real HIT data
- the fitting of the PDL curve is not terrible, the range is slightly underestimated. The kB parameters looses its meaning apparently and is strongly dependent on other fit parameters initial value. The PDD reconstructed using the Bortfeld formula and PDL fit parameters with the Birks(Bortfeld) attempt shows a shift of the peak trough the small dose region
- the excercise is not correct. The usage of the dose (particle_fluence*dEdx) in the Birks formula is not correct. The correct implementation is particle_fluence*Birks(dEdx).
- slides and code
Will merge the code with the latest version from Saad
Will finalise the market research draft

Set up parallel GEANT4 project from a basic example to rebuild Laurent's simulation from scratch.
Analysed SOBP data from HIT 12th April 2019, was able to successfully fit data but realised that data acquisition missed some of the beam delivery. Shown in this this presentation.
- Moved away from current binned fitting implementation, in favour of ROOT's fitting option "I" and using smooth QB function to fit data. Fit speed roughly the same. Note: SOBP fit fails with this option, but fit results are fine without it. SOBP fit takes ~10mins with original binned fit implementation, takes 10s with smooth QB fit.
Started research into FPGA programming:
- Some basic theory of logic gates, LUTs, Flip-flops etc.
- Ran hardware-version of 'Hello World' on Zybo: program board to blink an LED.
Laurent will get in touch with Stephan Brons about HIT FLUKA curves for He, C and O beams.
Laurent suggested that analysis of x-axis profile of beam is possible with CMOS sensor – could be worth investigating.