Proton Calorimetry/Meetings/2017/12/06: Difference between revisions

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* Working on [http://www.hep.ucl.ac.uk/pbt/wikiData/presentations/2017/DW_LeCroyRoutines_06-12-17.pptx ROOT fitting for LeCroy binary data]:
* Working on [http://www.hep.ucl.ac.uk/pbt/wikiData/presentations/2017/DW_LeCroyRoutines_06-12-17.pptx ROOT fitting for LeCroy binary data]:
** Two classes for loading (LeCroyData) and analysing data
** Two classes for loading (LeCroyData) and analysing (LeCroySpectrum) data.
** Methods that get time/voltage arrays for individual triggers reset time to zero.
** Current integration in LeCroySpectrum chooses region based on voltage levels: '''SJ''' and '''LK''' suggested more robust to use time window.  '''ABF''' said Caen integration window 100–200 ns.
* Will contact '''Tony Price''' at Birmingham regarding taking some data with trackers!
 
'''JS''':
* Investigating alternative methods for [http://www.hep.ucl.ac.uk/pbt/wikiData/presentations/2017/JS_Different_Curve_fitting_method_6-12-17.pptx fitting to Matthieu's simulated energy spectrum for Clatterbridge data].


'''ABF''':
'''ABF''':
* Fitting finally seems to work for single module spectrum:
* Investigating [http://www.hep.ucl.ac.uk/pbt/wikiData/presentations/2017/ABF_groupMeeting_06.12.17_fitStudies.pdf difference between MC truth and energy resolution returned by fit]:
** Landau-Gaussian convolution with second degree polynomial.
** Adjusting energy resolution of scintillator (nominally 8.5%): gives Monte Carlo truth resolution of 1.36% at 60MeV.
** ROOT requires specific order: fits Landau-Gaussian first.
** Fit resolution doesn't change with increasing energy resolution.
** Small features on the left of peak show extra 'wrinkle' which is not quite fitted; not present in July'15 data with UCL negative base.
** Spectra look very similar for different scintillator resolutions: overlap within error?
** Fit worse for MedAustron data but likely to be a result of pile-up.
** Will run simulations with very small resolutions and dig further into fit.
** FWHM from fit overestimates resolution slightly.
* Will chase up Hamamatsu regarding flat panels.
* Hamamatsu provided quote for flat panel detectors:
** Contact person Simon Whitehead.
** Recommended C9730DK-10 with faster readout rate but larger noise.
** Will ask for quote for C9728SK-10 and check which has larger dynamic range.
** Will also check whether we can get demo model to test: full cost £16k + £2k for software.


'''MH''':
'''MH''':
* Working on staged simulation to improve speed:
* Run Clatterbridge simulations with angled stopper:
** Large speed difference between good and bad nodes: trying to script finding fastest nodes...
** Largest angular offset of 15 degrees means 0.75mm difference in depth.
** Time limit of 12 hours for medium queue: some jobs overrun due to slow nodes and get ejected.
** Angle offset causes spectrum to flatten.
* Also trying to visualise beam profile every 25mm:
** Can't define overlapping geometries: need to include parallel world with sensitive detectors.
** No response from Ben Morgan: will email Geant4 mailing list.
** Sensitive detectors provide speed up over writing data in the stepping action.
* Will look into getting Oyster cards for ENLIGHT meeting delegates.
 
'''RS''':
* Visit to Nuvia Monday/Tuesday:
** Requested 100x100mm sheets, 2mm or 3mm thick depending on reliability of production.
** Total thickness of 60mm
** Nuvia produce a thick piece of scintillator, then squeeze under heat to correct thickness, then cut out sheet.
** Previous issues result from lack of attention to pressing...
** Samples will arrive before Christmas (perhaps not all...).
** Hana about to go away on maternity leave...
* Should be possible to cut and polish samples before they arrive:
** Derek can cut some pieces from existing spares.
** '''Georgio Savini''' and '''David Brooks''' should have expertise on polishing.
** Nuvia may be able to polish themselves.
 
'''DW''':
* ROOT scripts for reading Lecroy binary files is now working.
** Defines classes for acquiring and manipulating data.
** Just got histogram spectrum working.
** Will reject bad pulses and pulses with high variation in baseline.
** Can output data to suitable file format.
 
'''JS''':
* Working on alternate fit for single module spectrum:
** Fit uses Landau-Gaussian convolution with extra exponential part.
** &Chi;<sup>2</sup> per NDF above 5.
* Not entirely dissimilar from Anastasia's fitting function...
* Will review in a week.


'''LK''':
'''LK''':
* All of last few weeks spent writing paper on '''Build-Up Effects in Proton Therapy''':
* Has written a talk for PPRIG...
** Struggling to define protonic build-up in robust way.
** Using 30% of Bragg peak good at high energy but poor at low energy.
** Bortfeld formula works in opposite direction: would rather not use fit (need to check with '''Adam Gibson''').
** Have contacted '''Tracey Underwood''' to review paper.

Latest revision as of 16:03, 6 December 2017

Minutes for UCL Proton Calorimetry Meeting, 6th December 2017 (D17, Physics & Astronomy, UCL)

Present

Simon Jolly, Laurent Kelleter, Anastasia Basharina-Freshville, Jordan Silverman, Dan Walker, Matthieu Hentz

DW:

  • Working on ROOT fitting for LeCroy binary data:
    • Two classes for loading (LeCroyData) and analysing (LeCroySpectrum) data.
    • Methods that get time/voltage arrays for individual triggers reset time to zero.
    • Current integration in LeCroySpectrum chooses region based on voltage levels: SJ and LK suggested more robust to use time window. ABF said Caen integration window 100–200 ns.
  • Will contact Tony Price at Birmingham regarding taking some data with trackers!

JS:

ABF:

  • Investigating difference between MC truth and energy resolution returned by fit:
    • Adjusting energy resolution of scintillator (nominally 8.5%): gives Monte Carlo truth resolution of 1.36% at 60MeV.
    • Fit resolution doesn't change with increasing energy resolution.
    • Spectra look very similar for different scintillator resolutions: overlap within error?
    • Will run simulations with very small resolutions and dig further into fit.
  • Will chase up Hamamatsu regarding flat panels.

MH:

  • Run Clatterbridge simulations with angled stopper:
    • Largest angular offset of 15 degrees means 0.75mm difference in depth.
    • Angle offset causes spectrum to flatten.

LK:

  • Has written a talk for PPRIG...