Proton Calorimetry/Meetings/2017/11/29: Difference between revisions

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=== Present ===
=== Present ===


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


'''ABF''':
'''ABF''':
* Spoke to '''Ruben Saakyan''' about Nuvia sheets:
* Fitting finally seems to work for single module spectrum:
** '''Ruben''' visiting Prague in the next few weeks.
** Landau-Gaussian convolution with second degree polynomial.
** Waiting for Nuvia to determine whether they can do 2 mm sheets.
** ROOT requires specific order: fits Landau-Gaussian first.
* Spoke to Hamamatsu about flat panel detectors:
** 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.
** Contact person might be called Simon...
** Fit worse for MedAustron data but likely to be a result of pile-up.
** Preferred detector 50x50 mm version: will check the differences.
** FWHM from fit overestimates resolution slightly.
* Working on fitting to single module spectrum:
* Hamamatsu provided quote for flat panel detectors:
** Issues with fitting in ROOT: version dependent...
** Contact person Simon Whitehead.
** Now fitting to tail as well as peak, but transition still needs work.
** Recommended C9730DK-10 with faster readout rate but larger noise.
** Will add in exponential term to 'join' two parts of fit.
** 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.


'''JS''':
'''MH''':
* Spoke to '''Glen Cowan''' at RHUL on ROOT curve fitting:
* Working on staged simulation to improve speed:
** Suggested to add in another convolution;
** Large speed difference between good and bad nodes: trying to script finding fastest nodes...
** If that doesn't work, try doing piecewise fit.  
** Time limit of 12 hours for medium queue: some jobs overrun due to slow nodes and get ejected.
* Will prototype in Python before moving over to ROOT.
* 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''':
'''DW''':
* Very close to finishing off producing spectra from Lecroy binary files.
* ROOT scripts for reading Lecroy binary files is now working.
* Will then move on to curve fitting...
** Defines classes for acquiring and manipulating data.
** Just got histogram spectrum working.
'''MH''':
** Will reject bad pulses and pulses with high variation in baseline.
* Running Clatterbridge simulations with changes in nozzle cap angle:
** Can output data to suitable file format.
** Very little difference in spectra.
 
** OMA Monte Carlo school indicated overlap in geometry boundaries may be a problem...
'''JS''':
* Changed how particles recorded from stepping action to sensitive detector.
* Working on alternate fit for single module spectrum:
* Given up on installing Geant4 on MacBook Pro: will switch over to piss poor Lenovo CDT laptop:
** Fit uses Landau-Gaussian convolution with extra exponential part.
** '''SJ''' will ask '''Tim Scanlon''' about swapping for a machine with more horsepower.
** &Chi;<sup>2</sup> per NDF above 5.
* Not entirely dissimilar from Anastasia's fitting function...
* Will review in a week.


'''LK''':
'''LK''':
* Discussing build-up paper with '''Adam Gibson''':
* All of last few weeks spent writing paper on '''Build-Up Effects in Proton Therapy''':
** Simplified definition of build-up to be based on Bragg curve.
** Struggling to define protonic build-up in robust way.
** Understanding more about the physics!
** Using 30% of Bragg peak good at high energy but poor at low energy.
** Reran simulations at higher energies: absorber too small.
** Bortfeld formula works in opposite direction: would rather not use fit (need to check with '''Adam Gibson''').
** Will contact various OMA colleagues to understand origin of high entrance dose for protons above 200&nbsp;MeV.
** Have contacted '''Tracey Underwood''' to review paper.

Latest revision as of 15:30, 29 November 2017

Minutes for UCL Proton Calorimetry Meeting, 22nd November 2017 (D17, Physics & Astronomy, UCL)

Present

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

ABF:

  • Fitting finally seems to work for single module spectrum:
    • Landau-Gaussian convolution with second degree polynomial.
    • ROOT requires specific order: fits Landau-Gaussian first.
    • 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.
    • Fit worse for MedAustron data but likely to be a result of pile-up.
    • FWHM from fit overestimates resolution slightly.
  • 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:

  • Working on staged simulation to improve speed:
    • Large speed difference between good and bad nodes: trying to script finding fastest nodes...
    • Time limit of 12 hours for medium queue: some jobs overrun due to slow nodes and get ejected.
  • 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.
    • Χ2 per NDF above 5.
  • Not entirely dissimilar from Anastasia's fitting function...
  • Will review in a week.

LK:

  • All of last few weeks spent writing paper on Build-Up Effects in Proton Therapy:
    • 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.