HAWC Simulation and Analysis Buckley Hopper University of Maryland
Outline • HAWC geometry • Simulation versions and locations of important files • Usage instructions • Time required to simulate • Sensitivity to a Crab-like source • Areas of further study
30 PMTs 30 PMTs 3mm 3mm 160.08m 2m 2m 2cm 5m 4m 3.5m 145m HAWC Geometry • 30x30 PMTs • 5-meter spacing • 4-meter depth • Full-height curtains • Building • 3-mm-thick steel walls and roof • 2-meter-high walls 3mm 3mm
Simulation Versions and Locations of Important Files • Corsika version 6.5021 • g4sim version 2.1 • Corsika library /data/montecarlo/CorsikaHE • Geometry file g4sim/config/hawc900geom.dat • Survey file milinda/config_minihawc/hawc900survey.txt • g4sim output /data/montecarlo/sim/GEANT4/miniHAWC/sets/30x30/4300m /5mSpacing/4mDepth • Root file /data/montecarlo/sim/GEANT4/miniHAWC/root/ HAWC_4300m_5mSpacing_4mDepth_30x30_nonoise.root
Usage Instructions: g4sim • Get and build g4sim • Get milinda (for survey file) • Point CONFIG_MINIHAWC environment variable at the milinda/config_minihawc directory • Set variables in config.pl to proper values for Corsika library, repository location • Set $GGeom in config.pl to hawc900geom.dat
Usage Instructions: Making a Root File • Get milinda • Run makelibs in the lib directory • Use example UserTasks_MC.cc and accompanying makefile to build a milinda executable • Point CONFIG_MINIHAWC environment variable at the milinda/config_minihawc directory
Usage Instructions: Using MMCAnalysis on a Root File • Get milinda • Run makelibs in the lib directory • In a root script, use the command gSystem->Load(“<milinda_dir>/lib/ MMCAnalysis.so"); • Then use Milagro_MC *mc = new Milagro_MC(“<root_file>"); • Look at tools/MMCAnalysis.cc and include/MMCAnalysis.h for further information
Time Required to Simulate • 1 million gamma showers takes about 15 days of cpu time (average job of 20,000 showers requires ~7.24 hours). • 1 million proton showers takes about 20 days of cpu time (average job of 38,000 showers requires ~18.79 hours). • Limiting factor is the proton showers. • Example: nhit>200 and cxpe=8, only 1 in 116852 protons passes the cuts. • Currently have 1,508,971 gammas and 2,453,891 protons simulated, and growing.
Sensitivity to a Crab-Like Source Relative to Milagro • Using standard cuts, the Milagro Monte-Carlo predicts 9 gammas per day from the Crab, with a background of 2.5 protons per day. This assumes a 1.2-degree bin size. • In the Milagro experiment, we observe 10 gammas per day from the Crab, with a background of 1500 protons per day. • I use Sensi with a Crab spectrum and different nhit/nfit and cxpe cuts and an optimum bin size for each set of cuts to generate a rate of gammas and protons per day for HAWC. • To get an estimate of the signal and background for HAWC: • HSig = MilSig*(HGRate/MilGRate) • HBkg = MilBkg*(HPRate/MilPRate)*(HBin/MilBin)^2 • To find the sensitivity of HAWC relative to Milagro for different cuts, I use the following: • Q = (MilBin/HBin)*(HGRate/MilGRate)/sqrt(HPRate/MilPRate)
Further Study • Need more protons to explore the highest energies. Want to produce a plot of HAWC sensitivity versus other detectors for a Crab-like source. • Need to examine sensitivity to other types of sources, GRBs, etc. • Modify geometry in various ways – make building more realistic, look at other tube and curtain layouts.