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g. miniHAWC. mini- H igh A ltitude W ater C herenkov experiment. Jordan Goodman University of Maryland. Lexicon. Milagro – Existing water Cherenkov wide-field all-sky gamma-ray observatory near Los Alamos, NM.
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g miniHAWC mini- High Altitude Water Cherenkov experiment Jordan Goodman University of Maryland Jordan Goodman Beijing – June 2006
Lexicon • Milagro – Existing water Cherenkov wide-field all-sky gamma-ray observatory near Los Alamos, NM. • HAWC – A ambitious effort to construct an wide-field all-sky observatory with point source sensitivity of the Whipple 10m. • miniHAWC – Demonstrate HAWC technology at low cost with Milagro PMTs and instrumentation, with potentially large scientific payoff. Jordan Goodman Beijing – June 2006
Detector Layout HAWC: 5625 or 11250 PMTs (75x75x(1 or 2)) Single layer at 4m depth or 2 layers at Milagro depths Instrumented Area: 90,000m2 PMT spacing: 4.0m Shallow Area: 90,000m2 Deep Area: 90,000m2 miniHAWC: 841 PMTs (29x29) 5.0m spacing Single layer with 4m depth Instrumented Area: 22,500m2 PMT spacing: 5.0m Shallow Area: 22,500m2 Deep Area: 22,500m2 Milagro: 450 PMT (25x18) shallow (1.4m) layer 273 PMT (19x13) deep (5.5m) layer 175 PMT outriggers Instrumented Area: ~40,000m2 PMT spacing: 2.8m Shallow Area: 3500m2 Deep Area: 2200m2 Jordan Goodman Beijing – June 2006
Altitude 4300m 2600m Difference between 2600m (Milagro) and 4300m (Tibet): ~ 6x number of particles ~ 2x lower energy threshold Jordan Goodman Beijing – June 2006
Detector Layout Milagro 1.5 m Milagro: 2 layers at depths 1.5m – “Air Shower” Layer 5.5m – “Muon” Layer 5.5 m 2.8 m miniHAWC: Single intermediate layer opaque curtains between cells miniHAWC 5 m 4m Jordan Goodman Beijing – June 2006
Curtains • A high altitude version of Milagro would trigger at >10kHz. Need to control spurious triggers due to single muons. • Install curtains to optically isolate the PMTs. • Intrinsic Gamma hadron separation Jordan Goodman Beijing – June 2006
Milagro Instrumentation • 899 8” Hamamatsu PMTs • Bases, encapsulation • Single rg59 cable for data and HV. • Custom front end boards • Signal shaping and threshold detection • Trigger primitive generation • Pulse height through TOT method. • FastBus TDC’s • Capable of ~2000Hz or 6MB/s readout • VME-FastBus interface for readout Jordan Goodman Beijing – June 2006
Gamma/Hadron Separation Lateral distribution of EM energy and muons. Jordan Goodman Beijing – June 2006
Simulation Strategy • Use Milagro Simulation/Reconstruction software (without weighting). • Use observed Milagro crab signal to anchor simulations to reality. Shared systematics with Milagro. • Use new g/hadron discrimination variable for HAWC/miniHAWC that excludes the core location. CMilagro = (nPMTs > 2 PE)/(Max “muon layer” hit) CminiHAWC =(nPMTs > 2 PE)/(Max “muon layer” hit >20m from core) Jordan Goodman Beijing – June 2006
Triggering with Curtains • Multiplicity trigger at ~70 PMTs gives same • trigger rate as Milagro at 50 PMTs • Much higher Gamma area. protons gammas Jordan Goodman Beijing – June 2006
Q (sig/√bg) ( miniHAWC/Milagro) = 15 Single layer doesn't limit sensitivity miniHAWC Sensitivity Significance from Crab Transit (~5 hr) 4s Crab signif/year 80s 5s point source sensitivity reach ~60mCrab of 1 year survey Energy Resolution ~30% above median Angular Resolution 0.25O-0.40O Energy (Crab Spectrum, nTop/cxPE>5.0., q<30O) nTrig>50 Ethr~700 GeV nTrig>200 Ethr~2TeV S/B (hard cuts) ~ 1:1 for Crab Typical day 20 excess on 25 bkg Jordan Goodman Beijing – June 2006
Angular Resolution s = ~0.4o s = ~0.25o n Trigger = 50 n Trigger = 200 Jordan Goodman Beijing – June 2006
/ hadron Separation Q Factor (sig/√bg) Cuts soft hard miniHawc 2 4.5 Hess 3.2 4.4 Hess eg = 56% -> 28% eCR=3% -> 0.4% (shape only) Cut: nTop/cxPE>5.0 Eff g = 34% Eff CR= 3% Cut: nTop/cxPE>5.0 Eff g = 56% Eff CR= 1.5% Jordan Goodman Beijing – June 2006
30 GeV 70 GeV 230 GeV Gammas 270 GeV 20 GeV 70 GeV Protons Gamma/Hadron Separation Size of miniHAWC Size of Milagro deep layer Jordan Goodman Beijing – June 2006
Effective Area Gamma Area: q<30o nTop/cxPE>5.0 Dq<1.0O 200 PMT Trigger 80 PMT Trigger 20 PMT Trigger Pond Area Jordan Goodman Beijing – June 2006
Comparison of Effective Areas 50 Tube Trigger Jordan Goodman Beijing – June 2006
Sensitivity Increase from Milagro to MiniHawc • 15x Sensitivity increase over Milagro ~3x from Altitude, Area ~3x from g/hadron separation ~1.5x from Angular resolution • ~60mCrab sensitivity (5s in 1year) Jordan Goodman Beijing – June 2006
GRB Sensitivity Milagro miniHAWC Fluence Sensitivity to 100s GRB. Both Milagro and miniHAWC can “self trigger” and generate alerts in real time. GRB rate in FOV ~100 GRB/year (BATSE rate) Jordan Goodman Beijing – June 2006
The Diffuse Galactic Plane in miniHAWC and HAWC Use Neutral H map to trace out VHE Gamma-Ray flux. Normalize to Milagro observed TeV diffuse emission from the Galactic plane. Jordan Goodman Beijing – June 2006
Pond Design • Fiducial volume: 150m x 150m x 4m • Actual size: 170m x 170m x 5m • 1:1 slope at perimeter • Min 4½m depth to allow for 4m over PMTs. • Total volume: 115 Ml 170m 6m 4.5-5.0 m 150m Jordan Goodman Beijing – June 2006
Building Construction • Prefabricated steel building • Components manufactured at factory. • Shipped to site (~9 trucks) • Beams bolted not welded. • Cost ~1M$ (not installed) • Building installation ~400 k$ • Pond excavation ~300 k$ • Liner cost ~600 k$ Total facility cost ~2.5-3.0M$ 170m 170m Jordan Goodman Beijing – June 2006
Sierra Negra, Mexico ~1 ½ hr drive from Puebla ~4hr drive from Mexico City Saddle between Sierra Negra (z=4500m) and Orizaba (z=5600m) Site under development as a multiuse scientific facility. Jordan Goodman Beijing – June 2006
Sierra Negra, Mexico Elevation = 4030m Latitude = 19O 00’N Longitude = 97O 17’ W Jordan Goodman Beijing – June 2006
La Paz, Bolivia • Population: 1 Million • Elevation: 3900-2900 meters • Airport in El Alto • < 30 min from downtown • Elevation 4100 m • El Alto pop. 0.5 Million Jordan Goodman Beijing – June 2006
El Alto viewed from Mt. Chacaltaya Jordan Goodman Beijing – June 2006
Potential Sites Mt. Chacaltaya Cosmic Ray Laboratory 4806 meters +- 13 meters • South 16 deg 22.381’ • West 68 deg 08.758’ 4443 meters +- 10 meter • South 16 deg 24.837’ • West 68 deg 08.979’ Grid on Map is 1 km x 1km Water is plentiful, maybe too much so. Latitude: 16O 30’ S Longitude: 68O 11’ W La Paz El Alto Jordan Goodman Beijing – June 2006
YBJ Laboratory – Tibet, China Elevation: 4300m Latitude: 30O 13’ N Longitude: 90O 28’ E Lots of space. Available power. Available water. Tibet Air Shower Array Jordan Goodman Beijing – June 2006
YBJ Laboratory – Tibet, China Also home of ARGO observatory. ARGO utilizes RPC’s for EM particle detection. No Calorimetry. Jordan Goodman Beijing – June 2006
Milagro:3.5 GV Sierra Negra: 7.7 GV Tibet- 13.1 GV La Paz: 12.0 GV Geomagnetic Cutoff Singles rates at sites under consideration are reduced by ~20-30% due to improved geomagnetic cutoff. Jordan Goodman Beijing – June 2006
Triggering and DAQ • Milagro DAQ in its current form should be capable of triggering to multiplicities as low as ~80 PMTs. (~1800 Hz) • Simulation indicates that we can reconstruct gamma-ray events as small as ~20 PMTs. • Potentially huge sensitivity increase to GRBs if DAQ can be easily upgraded. Jordan Goodman Beijing – June 2006
DAQ Upgrade • Move to VME TDC bases DAQ. • CAEN 1190 • Capable of >40MB/s • 10-20kHz Readout. • Cost ~100k$ Jordan Goodman Beijing – June 2006
Costs • Facility ~$3M • Excavation, Liner, Building, Roads etc. • Water Recirculation System ~$50k • Cabling DAQ Upgrade ~$200k • Other costs: ~$600k? • Computing, Archiving, Monitoring, Cooling, Shipping… • Getting the Water (site dependent) • Electrical (site dependent) • Communications (site dependent) Jordan Goodman Beijing – June 2006
Summary • 15x Sensitivity increase over Milagro • ~60mCrab sensitivity (5s in 1year) • Mostly proven technology • Leverage $1.5M investment in Milagro equipment • Could construct rapidly if site available. • Next Logical Step toward HAWC Jordan Goodman Beijing – June 2006
DC2 Catalog (from J McEnery) Conclusion Jordan Goodman Beijing – June 2006
HAWC: Simulated Sky Map • C&G AGN • Hartmann IR model • known TeV sources • Milagro extended sources • 1-year observation Jordan Goodman Beijing – June 2006
1500 hrs/fov 7 min/fov 4 min/fov 1500 hrs/fov Survey Sensitivity Jordan Goodman Beijing – June 2006
EGRET Crab Nebula GLAST Current synoptic instruments Whipple VERITAS/HESS miniHAWC HAWC Detector Sensitivity (Single Location) Jordan Goodman Beijing – June 2006