1. Standard Candle, Flasher, and Cascade Simulations in IceCube Michelangelo D’Agostino UC Berkeley PSU Analysis Meeting June 21-24, 2006

2. Outline motivations motivations mechanics of the simulation chain mechanics of the simulation chain detailed comparisons of standard candle simulations and data detailed comparisons of standard candle simulations and data future work future work

3. Motivations for a cascade analysis, the detector response to point sources of light needs to be studied with in- situ light sources for a cascade analysis, the detector response to point sources of light needs to be studied with in- situ light sources for cascades, these light sources are the analogue of atmospheric muons: they ensure the simulation is behaving reasonably for cascades, these light sources are the analogue of atmospheric muons: they ensure the simulation is behaving reasonably the flashers and the standard candle are a good way to check the low-level mechanics of the simulation the flashers and the standard candle are a good way to check the low-level mechanics of the simulation for the standard candle, we’ve calibrated how many photons are entering the ice, so it’s an absolute check on the simulation for the standard candle, we’ve calibrated how many photons are entering the ice, so it’s an absolute check on the simulation

4. Standard Candle Basics 337 nm pulsed nitrogen laser (compared to 405 nm for the flashers) 337 nm pulsed nitrogen laser (compared to 405 nm for the flashers) Cherenkov sculpting from the reflective cone Cherenkov sculpting from the reflective cone deployed on string 40 between DOM’s 22 and 23 deployed on string 40 between DOM’s 22 and 23

5. The Simulation Chain source module that puts a cascade in the ice at a certain position in the ice flash-generator SC-generator or simple-generator or PSInterface Photonics Tables hit-constructor romeo-interface DOMsimulator PMT simulation Output: whether a given DOM has been hit, whether the local coincidence conditions have been satisfied, and the waveform for that DOM EVERYTHING ABOUT THE INDIVIDUAL LIGHT SOURCE IS CONTAINED HERE!!

6. Photonics takes into account the fully layered ice properties and the wavelength dependence of the scattering and absorption takes into account the fully layered ice properties and the wavelength dependence of the scattering and absorption propagates the photons and stores the results in tables propagates the photons and stores the results in tables to add a new point light source like a flasher or a standard candle, one simply specifies the theta and phi light distribution to add a new point light source like a flasher or a standard candle, one simply specifies the theta and phi light distribution trick the simulation into calling up the right table trick the simulation into calling up the right table

7. Comparisons to Data all comparisons were made to a standard candle run taken on February 2nd (string 49 was not quite frozen in and was excluded from this analysis) all comparisons were made to a standard candle run taken on February 2nd (string 49 was not quite frozen in and was excluded from this analysis) V01-09-00 of the simulation project V01-09-00 of the simulation project 100% brightness (~40 PeV equivalent cascade energy) 100% brightness (~40 PeV equivalent cascade energy) quite a few DOM’s were not yet turned on quite a few DOM’s were not yet turned on TestDAQ data; implications for local coincidence TestDAQ data; implications for local coincidence number of photons per flash is the only tunable parameter— match multiplicities and see how the occupancies and charges and other quantities look number of photons per flash is the only tunable parameter— match multiplicities and see how the occupancies and charges and other quantities look search for consistency, but we can also compare the absolute photon numbers search for consistency, but we can also compare the absolute photon numbers

8. Importance of Local Coincidence no local coincidence 0 to 800 ns local coincidence -350 to 400 ns local coincidence this is what’s set in the run configuration estimate of TestDAQ equivalent with cable delays

9. Occupancies by String 0 to 800 ns local coincidence -350 to 400 ns local coincidence no local coincidence

10. Best Agreement 3.0e12 photons per flash, without string 49 4.0e12 photons per flash, without string 49 actual number: 5.75e12 photons with an uncertainty that’s still being determined

11. Occupancies for 3.0e12

12. Charges

14. Distance vs. Leading Edge Time by String

15. Distance vs. Leading Edge Time by String

16. Sim Data Average Waveforms

17. Sim Data Average Waveforms ATWD saturation PMT saturation

18. Conclusions and Issues for the Future the agreement between simulation is very encouraging the agreement between simulation is very encouraging need to nail down TestDAQ local coincidence need to nail down TestDAQ local coincidence timing offsets timing offsets PMT saturation—needs to be properly taken into account PMT saturation—needs to be properly taken into account DOM efficiencies? DOM efficiencies?