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Title: Comparing the Calibration and Simulation Data of the Cryogenic Dark Matter Search

Abstract

The Cryogenic Dark Matter Search, or CDMS, collaboration is preparing a new experiment called SuperCDMS. CDMS uses Germanium detectors to attempt the direct detection of dark matter. To do this, they measure the ionization and heat produced during an event where a WIMP scatters off of germanium crystal lattice. To prepare for the experiment the detectors are calibrated with various radioactive sources. The response of the detectors is also modeled by a Monte Carlo simulation. These simulations include modeling everything from the radiation production to the raw data collected by the detector. The experimental data will be used to validate the results of the detector simulation. This research will look only at the phonons produced during events that occur very close to the detector surface. From the raw data and simulation output three parameters will be determined: the rise time, the decay time, and time to position independence. It was found that the simulation's risetime and time to position independence was generally smaller than that of the data, while the decay time was found to be larger in the simulation than in the data. These differences show that the simulation is not complete. The difference in risetime implies that themore » phonons are not spread out enough when they reach the detector walls, which would be improved by a look at the Luke phonon and charge transport. The long decay time in the simulation implies that the rate phonons are being absorbed is underestimated. Finally, the small time to position independence in the simulation could be due to a low phonon scattering rate. A simple solution may be to alter the parameters that control the simulation, while still remaining physically sensible, to help match simulation and data.« less

Authors:
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1017225
Report Number(s):
SLAC-TN-11-004
TRN: US1103335
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CALIBRATION; CHARGE TRANSPORT; CRYOGENICS; CRYSTAL LATTICES; DECAY; DETECTION; GE SEMICONDUCTOR DETECTORS; GERMANIUM; IONIZATION; NONLUMINOUS MATTER; PHONONS; PRODUCTION; PULSE RISE TIME; RADIATIONS; SCATTERING; SIMULATION; Astrophysics,Other

Citation Formats

DiFranzo, Anthony, and /Rensselaer Poly. /SLAC. Comparing the Calibration and Simulation Data of the Cryogenic Dark Matter Search. United States: N. p., 2011. Web. doi:10.2172/1017225.
DiFranzo, Anthony, & /Rensselaer Poly. /SLAC. Comparing the Calibration and Simulation Data of the Cryogenic Dark Matter Search. United States. https://doi.org/10.2172/1017225
DiFranzo, Anthony, and /Rensselaer Poly. /SLAC. 2011. "Comparing the Calibration and Simulation Data of the Cryogenic Dark Matter Search". United States. https://doi.org/10.2172/1017225. https://www.osti.gov/servlets/purl/1017225.
@article{osti_1017225,
title = {Comparing the Calibration and Simulation Data of the Cryogenic Dark Matter Search},
author = {DiFranzo, Anthony and /Rensselaer Poly. /SLAC},
abstractNote = {The Cryogenic Dark Matter Search, or CDMS, collaboration is preparing a new experiment called SuperCDMS. CDMS uses Germanium detectors to attempt the direct detection of dark matter. To do this, they measure the ionization and heat produced during an event where a WIMP scatters off of germanium crystal lattice. To prepare for the experiment the detectors are calibrated with various radioactive sources. The response of the detectors is also modeled by a Monte Carlo simulation. These simulations include modeling everything from the radiation production to the raw data collected by the detector. The experimental data will be used to validate the results of the detector simulation. This research will look only at the phonons produced during events that occur very close to the detector surface. From the raw data and simulation output three parameters will be determined: the rise time, the decay time, and time to position independence. It was found that the simulation's risetime and time to position independence was generally smaller than that of the data, while the decay time was found to be larger in the simulation than in the data. These differences show that the simulation is not complete. The difference in risetime implies that the phonons are not spread out enough when they reach the detector walls, which would be improved by a look at the Luke phonon and charge transport. The long decay time in the simulation implies that the rate phonons are being absorbed is underestimated. Finally, the small time to position independence in the simulation could be due to a low phonon scattering rate. A simple solution may be to alter the parameters that control the simulation, while still remaining physically sensible, to help match simulation and data.},
doi = {10.2172/1017225},
url = {https://www.osti.gov/biblio/1017225}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jun 22 00:00:00 EDT 2011},
month = {Wed Jun 22 00:00:00 EDT 2011}
}