Standard Candle, Flasher, Standard Candle, Flasher, and Cascade Simulations in and Cascade Simulations in

IceCubeIceCube

Michelangelo D’Agostino

UC Berkeley

PSU Analysis Meeting

June 21-24, 2006

OutlineOutline

motivationsmotivations mechanics of the mechanics of the

simulation chainsimulation chain detailed comparisons detailed comparisons

of standard candle of standard candle simulations and datasimulations and data

future workfuture work

MotivationsMotivations

for a cascade analysis, the detector response for a cascade analysis, the detector response to point sources of light needs to be studied to point sources of light needs to be studied with in-situ light sourceswith in-situ light sources

for cascades, these light sources are the for cascades, these light sources are the analogue of atmospheric muons: they ensure analogue of atmospheric muons: they ensure the simulation is behaving reasonablythe simulation is behaving reasonably

the flashers and the standard candle are a the flashers and the standard candle are a good way to check the low-level mechanics good way to check the low-level mechanics of the simulationof the simulation

for the standard candle, we’ve calibrated for the standard candle, we’ve calibrated how many photons are entering the ice, so how many photons are entering the ice, so it’s an absolute check on the simulationit’s an absolute check on the simulation

Standard Candle Standard Candle BasicsBasics

337 nm pulsed 337 nm pulsed nitrogen laser nitrogen laser (compared to (compared to 405 nm for the 405 nm for the flashers)flashers)

Cherenkov Cherenkov sculpting from sculpting from the reflective the reflective conecone

deployed on deployed on string 40 string 40 between between DOM’s 22 and DOM’s 22 and 2323

The Simulation ChainThe 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!!

PhotonicsPhotonics

takes into account the fully layered ice takes into account the fully layered ice properties and the wavelength properties and the wavelength dependence of the scattering and dependence of the scattering and absorptionabsorption

propagates the photons and stores the propagates the photons and stores the results in tablesresults in tables

to add a new point light source like a to add a new point light source like a flasher or a standard candle, one simply flasher or a standard candle, one simply specifies the theta and phi light specifies the theta and phi light distributiondistribution

trick the simulation into calling up the trick the simulation into calling up the right tableright table

Comparisons to DataComparisons to Data

all comparisons were made to a standard candle run all comparisons were made to a standard candle run taken on February 2nd (string 49 was not quite frozen taken on February 2nd (string 49 was not quite frozen in and was excluded from this analysis)in and was excluded from this analysis)

V01-09-00 of the simulation projectV01-09-00 of the simulation project 100% brightness (~40 PeV equivalent cascade 100% brightness (~40 PeV equivalent cascade

energy)energy) quite a few DOM’s were not yet turned onquite a few DOM’s were not yet turned on TestDAQ data; implications for local coincidenceTestDAQ data; implications for local coincidence number of photons per flash is the only tunable number of photons per flash is the only tunable

parameter—match multiplicities and see how the parameter—match multiplicities and see how the occupancies and charges and other quantities lookoccupancies and charges and other quantities look

search for consistency, but we can also compare the search for consistency, but we can also compare the absolute photon numbersabsolute photon numbers

Importance of Local Importance of Local CoincidenceCoincidence

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

Occupancies by StringOccupancies by String

0 to 800 ns local coincidence

-350 to 400 ns local coincidence

no local coincidence

Best AgreementBest Agreement

3.0e12 photons per flash, without string 49

4.0e12 photons per flash, without string 49actual number: 5.75e12 photons with

an uncertainty that’s still being determined

Occupancies for Occupancies for 3.0e123.0e12

Charges

Charges

Distance

vs.

Leading Edge Time

by String

Distance

vs.

Leading Edge Time

by String

Sim

Sim

Data

Data

Average Waveforms

Sim

Sim

Data

Data

Average Waveforms

ATWD saturation PMT saturation

Conclusions and Issues Conclusions and Issues for the Futurefor the Future the agreement between the agreement between

simulation is very encouragingsimulation is very encouraging need to nail down TestDAQ local need to nail down TestDAQ local

coincidencecoincidence timing offsetstiming offsets PMT saturation—needs to be PMT saturation—needs to be

properly taken into accountproperly taken into account DOM efficiencies?DOM efficiencies?