2nd edition Amasim and Photonics Stephan Hundertmark Bartol 22 March 2004

History behind this implementation First implementation was slow, due to treatment of muons as many point sources Workshop in Laguna Beach (2003) showed great intrest to solve this problem Ped 'integrated' the photonics tables to get infinite muon tables the so called level2 photonics In the implementation the photonics coordinate system was changed Traditionally we talk about photonics a lot (it makes good workshops), but we never got it going We hope that the photonics treatment of the photon propagation will solve our ice related problems

Current Situation There are two interfaces to photonics availible: 1.) PSI in development by Thomas Burgess 2.) Scatserver developed by SH This is about the scatserver implementation Scatserver wraps the photonics call functions into TCP/IP calls

General Idea Implement the geometry conversion (amasim->photonics) Do low level checks, simple test cases for geometry Compare PTD bulk tables to photonics bulk tables => same input should produce same output The basic test is to compare the mean amplitude per OM for showers There is nothing like the same tables for PTD and photonics We check the mean of the mean amplitude per OM for many showers from a test stand, PTD and photonics runs on the same inputfile Main Goal: Solve our Ice related problems

The test stand: Isotropical distributed epairs of 10 GeV in a 100 m sphere The single downlooking OM is moved from the center of the sphere to +/- 100 m and +/- 200 m dist

What does the result look like -- 1st attempt Used the bulk ice s=24m f=0.96 for ptd and.. a bulk ice table from photonics that I had laying around on my hard drive ptd photonics What does this mean ? Photonics interface wrong ? Table wrong ? Both ? PTD interface wrong ?

Wow ! Let's try a new table... This is a photonics table I got from Paolo... (No blame here !) ptd photonics Wow ! => need to figure out what tables are used, ie. how they are produced Remark: I wanted to program the amasim interface not work with photonics

Produced my own set of bulk tables: ptd photonics - increased the dimensions of the generation volume - ptd like absorption => this looks already much better

Changing the variable we look at: amplitude vs. distance ptd photonics ...more intresting is the ratio ptd/photonics =>

The ratio is nearly constant as a function of distance Why is the ratio not 1 ? There are some efficencies Glass, Gel, QE ... What are the ptd settings for these efficencies... The statistics here was 1e7 photons OM @ z=0 OM @ z=100 OM @ z=-100 OM @ z=200 OM @ z=-200

List of efficencies from photonics README.eff Glass index of refraction Glass type (Benthos, Billings) Gel index of refraction Gel type Sensitivity, angular Quantum efficency model OM curvature correction Dynode efficency What are the ptd settings for these efficencies ? Made an educated guess ...

The ratio using my best guess for ptd settings in photonics Striking result: => By just changing the efficencies the mean amplitude changes by ~30% Question: Which efficency has the largest impact ? Is there one dominating ?

Went through the efficencies one by one always changing from the 'ptd-settings' only this one while retaining the rest Largest change in glass: Benthos describtion from dada_attn to Peter S. measurments then next largest is the description of the QE large uncertainties from input parameters we don't fully know

Conclusions for amasim/photonics interface there had been extensive debugging and comunication with Ped about the coordinates all test make sense by now the amasim/photonics interface works shown for the (shower) amplitudes but as coordinates are the same for muons and time access, the risks for surprises are low the next step is to check the timing distributions -> need for new tables after this muons and ice-layers ... there is a need for a more convenient comparison method between ptd/photonics tables this should not need to be done via amasim ultimatively we want to use Thomas PSI