1. Summary of yet another Photonics Workshop AMANDA/IceCube Collaboration Meeting Berkeley, March 19, 2005

2. Ice Model Basics
Need to describe Fphoton(A,t) around light sources (muon tracks, cascades, flashers, standard candles) for simulations of AMANDA events
Tables of Fphoton(A,t) are calculated using Monte Carlo propagation of photons through scattering and absorbing medium (ice)
Dependence on distance, OM orientation, ice properties, etc
Prefer to have simplifications (symmetries, averages, approximations) but must pay price for these

3. Light Scattering in South Pole ice
flat for bubbles
bubbles
power-law for dust
scattering by dust

4. Light Absorption in South Pole ice
flat (weak temp. dependence)
absorption
by ice
absorption follows dust profile

5. PTD vs. photonics: layering
Bulk PTD
Layered PTD
photonics 2 3 2 1 2 3 2 1 2 3 2
average ice
type type type 3
“real” ice

6. Photonics Workshop Agenda
Introduction Kurt Woschnagg ’
Photonics upgrades Thomas Burgess 10’
Status of photonics development Johan Lundberg ’
New features Michelangelo D’Agostino 15’
Photonics with simuperl Markus Ackermann 10’
Wuppertal photonics production Christopher Wiebusch 10’
Discussion All ’
Merging with Simulation Workshop

7. level2 photonics upgrades (Thomas Burgess)
“Oldschool” version of photonics
- one static global set of tables available
- cannot unload tables
New version
- allow several tables loaded at once
- enable table unloading
- good for:
finite muons
multiple muons

8. Making photonics work (Johan Lundberg)
Upgoing infinite muon
Bug fixes
Functionality rework:
- finite muons
Animations: muons in ice (bulk, layered)
dN(t)/dt Light distribution
dP(t)/dt Independent arriving photon pdf

9. New features (Michelangelo D’Agostino)
Realistic flasher source (option #8)
beamed flasher LED
regular cosθ LED
6 tilted LEDs +
6 horizontal LEDS

10. New features (Michelangelo D’Agostino)
2. Hole ice (around flasher source)

11. High statistics table production
Two sites:
AliceNext (Wuppertal)
SweGrid
Some discrepancies between tables
Make test tables
Compare (Johan)
If OK, high statistics tables

12. Using photonics in simulations (Rafael Lang)
Buggy tables used for this, but still…

13. Photonics and IceCube Using ROMEO with Photonics
Romeo simulates the waveform produced by light detection in ice
needs to know photon arrival theta and wavelength for each photon
estimates arrival direction, source distance and wavelength spectrum
first option:
produce photonics tables binned in arrival theta and wavelength (not available)
too big tables and requires work on photonics (not practical)
ROMEO has the needed information
second option:
use present tables
ROMEO needs to guess arrival direction, position on photocathode and wavelengths of photons
need to check estimation algorithm using photonics simulation itself
estimate systematic uncertainty on waveform determination by ROMEO

14. Message: photonics is good to go
Conclusion
We have entered the post-Ped era:
plenty of expertise at all levels
Photonics debugged and understood
we can do showers and muons
tables contain what we expect them to
It’s time to use it for physics simulations
Message: photonics is good to go