1. Midwest θ13 Meeting August 11, 2004 Matthew Worcester
Monte Carlo Work
Midwest θ13 Meeting
August 11, 2004
Matthew Worcester

2. Outline Additions to ReactorFsim CVS Documentation Future plans
Sources
PMT radioactivity
Muons
CVS
Documentation
Future plans

3. Sources 252Cf neutrons 208,210Tl γ’s 212,214Bi γ’s Watt spectrum
Prompt photons
Needs multiplicity
208,210Tl γ’s
Correct multiplicity and energies
212,214Bi γ’s

4. 252Cf source at R=0

5. Rate = NPMT × PMTradioactivity × Nγ
NPMT = 816 with R2 = 325 cm
PMTradioactivity ~ 10 decays/PMT/sec (for R5912s from Hamamatsu)
Nγ = number of γ in scintillating region from ReactorFsim with:

6. PMT radioactivity 10k decays generated at each oil buffer thickness
Isotropic γ production at each PMT
Each decay occurs at R2 = 325 cm
Compton scattering through the oil buffer
Equal #s of decays from 208Tl,210Tl,212Bi,214Bi

7. PMT radioactivity

8. Muons Starting points: Propagate muons through ReactorFsim
Muon flux with energy and zenith angle spectra underground with GEANT4 by Martina and Jim
Spallation cross-sections for 9Li, 8He from Hagner, et al. paper
Propagate muons through ReactorFsim
Just getting started

9. CVS CVS server running on cp4.uchicago.edu
First time users me to get a CVS account and password:
Instructions at:
Primitive versioning
No controls on CVS checkin: users must police themselves

10. Documentation
Online code browser:
Cross-linked listing of all ReactorFsim files
Available for each version of code
Generated with Doxygen
Requires additional documentation in the code (much more needs to be written)
TeX reference manual
Also from Doxygen

11. Future plans Finish muons Radioactivity from steel/acrylic parts
More studies (see Josh’s talk)
Decide how far to push this simulation:
Should we reconstruct entire events?
How to arrange the timing?

12. Scintillator teststand
Everyone at Chicago involved
Small (V ~ 360 mL) scintillating volume observed by two PMTs
Readout by ADCs and TDCs or oscilloscope
Muon veto counters
Initial goals: learn what we can, try pulse shape discrimination

13. Electronics

14. Pulse shape discrimination
Read out PMT pulses with ‘scope and sum both PMT
Find the pulse peak (t = 0)
Integrate for 300 ns:
Total charge from t = -10 ns (entire pulse)
Delayed charge from t = +25 ns (tail of pulse)

15. Pulse shape discrimination

16. Future teststand work Use other scintillators Larger system:
Gd-doped
Better PS discrimination
Larger system:
Cylinder (R ~ 20 inch, L ~ 1.5 m)
Observed by R5912 (low-rad glass) PMTs (some parts ordered)
Current DAQ easily upgradeable
Lots to do!