Proton Calorimetry/Meetings/2020/04/29

Minutes for UCL Proton Calorimetry Meetings, 29th April (Everyone is working from home)

Present

Simon Jolly, Laurent Kelleter, Saad Shaikh, Raffaella radogna

Raffaella Radogna

• Readed literature papers for ion beam treatment plan, in particular "M Krämer et al 2000 Phys. Med. Biol. 45 3299", "Krämer et al Med. Phys. 43 (4), April 2016", "Zhang Phys. Med. Biol. 56 (2011) 7725–7735"
• will start practicing with the QB fitting code
  • will change the fitting formula adding an exp tail to describe the fragmentation tail
  • will investigate the existence of tabulated functions for ion PDD. If PDD curves are tabulated, e.s. for the TRiP98 software, will investigate how to estimate the PDL using the Birks' law

Saad Shaikh

• Implemented Libdedx functions to retrieve CSDA ranges and dE/dx for protons, helium ions and carbon ions in either water or polystyrene. Used to provide initial range estimates in fitting process.
• Set up GEANT4 detector simulation to compile and run within Eclipse.
  • Will set up parallel basic example GEANT4 project to serve as template to rebuild Laurent's simulation.
• Implemented routine to construct reference SOBP curves from HIT FLUKA tables, given XML file of beam settings used. Will be used to compare reconstructed SOBP from QUARC.
  • Will analyse QUARC SOBP data this week.
• Raffy suggested a (temporary) option to fit exponential for fragment tail in ion fits.
  • Laurent suggested two straight lines might be better, as shown in Ying 2017. Will read this paper, but better to try implementing fragmentation properly.
• Laurent suggested to contact Lennart Volz about cross-section data for nuclear fragmentation.
  • Will get in touch with him later this week/early next week after reading Horst 2017.
• Laurent highlighted importance of direct particle hits in CMOS sensor, which might replace issue of detector alignment.
  • Already pulled and implemented code to estimate direct hits when implementing new cross-talk uncertainty calculation. How to do this with photodiodes?
• Laurent suggested that Birks' law should be modified to better handle high dE/dx in ion fits.
  • Will investigate second-order polynomial correction posed by Chou 1952.
• Simon suggested to start working on FPGA soon to communicate with new prototype detector front-end.
  • Try to get Zybo board to output a clock signal (e.g. 10MHz square-wave).
• Need to do 6-month research log entry.