1. Photonics Workshop AMANDA/IceCube Collaboration Meeting Berkeley, March 19, Going the last mile…

2. Photonics Workshop Objectives
Review where we stand
- Debugging/testing complete?
- Do we have all the tools we need?
Coordinate how we proceed
- Final go for mass production
Photonics in IceCube
- Do we have a plan? If not, make one
Photonics Workshop, Berkeley, March 19, 2005

3. Photonics Workshop Agenda
Introduction Kurt Woschnagg ’
Status of photonics development Johan Lundberg ’
Update on PSI Thomas Burgess 10’
New features Michelangelo D’Agostino 15’
Photonics with simuperl Markus Ackermann 10’
Wuppertal photonics production Christopher Wiebusch 10’
Discussion All ’
Merging with Simulation Workshop
Photonics Workshop, Berkeley, March 19, 2005

4. Photonics Workshop, Berkeley, March 19, 2005
Ice Model Basics
Need to describe Fphoton(A,t) around light sources (muon tracks, cascades) 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
Photonics Workshop, Berkeley, March 19, 2005

5. Light Scattering in South Pole ice
flat for bubbles
bubbles
power-law for dust
scattering by dust
Photonics Workshop, Berkeley, March 19, 2005

6. Light Absorption in South Pole ice
flat (weak temp. dependence)
absorption
by ice
absorption follows dust profile
Photonics Workshop, Berkeley, March 19, 2005

7. Light propagation codes: two approaches
PTD
Photons propagated through ice with homogeneous prop.
Uses average scattering
No intrinsic layering: each OM sees homogeneous ice, different OMs may see different ice
Fewer tables
Faster
Approximations
Photonics
Photons propagated through ice with varying properties
All wavelength dependencies included
Layering of ice itself: each OM sees real ice layers
More tables
Slower
Detailed
Photonics Workshop, Berkeley, March 19, 2005

8. Photonics Workshop, Berkeley, March 19, 2005
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
Photonics Workshop, Berkeley, March 19, 2005

9. Photonics Workshop, Berkeley, March 19, 2005
PTD-based ice models
MAM, mamint
asens
16-layer
“Kurt”, stdkurt, sudkurt
bulk
kgm
f125
See talk on ice models at Madison AMANDA meeting in 2003 for details
Photonics Workshop, Berkeley, March 19, 2005

10. Photonics Workshop, Berkeley, March 19, 2005
We’re getting there…
Photonics Workshop, Berkeley, March 19, 2005

11. airborne radar imaging
South Pole station
and AMANDA
airborne radar imaging
(Blankenship et al.)
For IceCube:
Are the dust layers horizontal
on km-scale?
The flat radar profile in lower left indicates a subglacial lake ~8 km from South Pole at depth 2.8 km.
It was once liquid and may still contain microbial life in a permafrost layer. It is hydraulically isolated.
It is a mix of sediment and ice.
IceCube
frozen subglacial lake
Photonics Workshop, Berkeley, March 19, 2005

12. Photonics Workshop, Berkeley, March 19, 2005
Discussion Topics
Table production: what, where, when
Systematics (special tables)
Special sources
Table fitting
Do we still have a size/memory problem?
NN fits
IceCube
L4?
Special needs:
Extended ice table
DOM description
Future complications
Non-horizontal dust layers (breaking the last symmetry)
Photonics Workshop, Berkeley, March 19, 2005