MiniHAWC Jordan Goodman Beijing – June 2006 Jordan Goodman University of Maryland mini- High...

Jordan GoodmanBeijing – June 2006

miniHAWC

Jordan GoodmanUniversity of Maryland

mini-High Altitude Water Cherenkov experiment

miniHAWC


miniHAWC

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.


miniHAWC

Detector Layout

Milagro:450 PMT (25x18) shallow (1.4m) layer273 PMT (19x13) deep (5.5m) layer175 PMT outriggers

Instrumented Area: ~40,000m2

PMT spacing: 2.8mShallow Area: 3500m2

Deep Area: 2200m2

HAWC:5625 or 11250 PMTs (75x75x(1 or 2))Single layer at 4m depth or 2 layers atMilagro depths

Instrumented Area: 90,000m2

PMT spacing: 4.0mShallow Area: 90,000m2

Deep Area: 90,000m2

miniHAWC:841 PMTs (29x29)5.0m spacingSingle layer with 4m depth

Instrumented Area: 22,500m2

PMT spacing: 5.0mShallow Area: 22,500m2

Deep Area: 22,500m2


miniHAWC

4300m

2600m

Difference between 2600m (Milagro) and 4300m (Tibet):~ 6x number of particles~ 2x lower energy threshold

Altitude


miniHAWC

Detector Layout

Milagro: 2 layers at depths1.5m – “Air Shower” Layer5.5m – “Muon” Layer

miniHAWC: Single intermediate layeropaque curtains between cells

4m

5.5

m

5 m

2.8 m

1.5

m


miniHAWC

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


miniHAWC

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


miniHAWC

Gamma/Hadron Separation

Lateral distribution of EM energy and muons.


miniHAWC

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 /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)


miniHAWC

Triggering with Curtains

• Multiplicity trigger at ~70 PMTs gives same trigger rate as Milagro at 50 PMTs• Much higher Gamma area.

protonsgammas


miniHAWC

Energy (Crab Spectrum, nTop/cxPE>5.0., <30O)Significance fromCrab Transit (~5 hr) 4

Crab signif/year 80

5 point source sensitivity reach ~60mCrabof 1 year survey

Energy Resolution ~30% above median

Angular Resolution 0.25O-0.40O

S/B (hard cuts) ~ 1:1 for CrabTypical day 20 excess on 25 bkg

miniHAWC Sensitivity

Q (sig/√bg) ( miniHAWC/Milagro) = 15Single layer doesn't limit sensitivity

nTrig>50

Ethr~700 GeV

nTrig>200

Ethr~2TeV


miniHAWC

= ~0.4o = ~0.25o

Angular Resolution

n Trigger = 50 n Trigger = 200


miniHAWC

/ hadron Separation

Cut: nTop/cxPE>5.0Eff = 34%Eff CR= 3%

Cut: nTop/cxPE>5.0Eff = 56%Eff CR= 1.5%

= 56% -> 28%

CR= 3% -> 0.4%

(shape only)

Hess Q Factor (sig/√bg)

Cuts soft hard

miniHawc 2 4.5

Hess 3.2 4.4


miniHAWC

Gamma/Hadron Separation

Gammas

Protons

30 GeV 70 GeV 230 GeV

20 GeV 70 GeV 270 GeVSize of miniHAWC

Size of Milagro deep

layer


miniHAWC

Effective AreaGamma Area: <30o nTop/cxPE>5.0 <1.0O

200 PMT Trigger80 PMT Trigger20 PMT Trigger Pond Area


miniHAWC

Comparison of Effective Areas

50 Tube Trigger


miniHAWC

Sensitivity Increase from Milagro to MiniHawc

• 15x Sensitivity increase over Milagro~3x from Altitude, Area~3x from /hadron separation~1.5x from Angular resolution

• ~60mCrab sensitivity (5 in 1year)


miniHAWC

GRB Sensitivity

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)

MilagrominiHAWC


miniHAWC

The Diffuse Galactic Plane in miniHAWC and HAWC

Use Neutral H map to trace out VHE Gamma-Ray flux. Normalize to Milagroobserved TeV diffuse emission from the Galactic plane.


miniHAWC

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

150m

4.5-5.0 m 6m


miniHAWC

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


miniHAWC

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.


miniHAWC

Sierra Negra, Mexico

Elevation = 4030mLatitude = 19O 00’NLongitude = 97O 17’ W


miniHAWC

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


miniHAWC

El Alto viewed from Mt. Chacaltaya


miniHAWC

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’

Mt. ChacaltayaCosmic Ray Laboratory

La Paz

El Alto

Grid on Mapis 1 km x 1km

Potential Sites

Water is plentiful, maybe too much so.

Latitude: 16O 30’ SLongitude: 68O 11’ W


miniHAWC

YBJ Laboratory – Tibet, China

Elevation: 4300mLatitude: 30O 13’ NLongitude: 90O 28’ E

Lots of space.Available power.Available water.

Tibet Air Shower Array


miniHAWC

YBJ Laboratory – Tibet, China

Also home of ARGO observatory.

ARGO utilizes RPC’s for EM particle detection.

No Calorimetry.


miniHAWC

Geomagnetic Cutoff

Milagro:3.5 GV

Tibet- 13.1 GVLa Paz: 12.0 GV

Sierra Negra: 7.7 GV

Singles rates at sites under consideration are reduced by ~20-30% due to improved geomagnetic cutoff.


miniHAWC

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.


miniHAWC

DAQ Upgrade• Move to VME TDC bases DAQ.

• CAEN 1190• Capable of >40MB/s • 10-20kHz Readout.• Cost ~100k$


miniHAWC

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)


miniHAWC

Summary

• 15x Sensitivity increase over Milagro

• ~60mCrab sensitivity (5 in 1year)

• Mostly proven technology– Leverage $1.5M investment in Milagro equipment– Could construct rapidly if site available.

• Next Logical Step toward HAWC


miniHAWC

Conclusion

DC2 Catalog (from J McEnery)


miniHAWC

HAWC: Simulated Sky Map

C&G AGN

Hartmann IR model

known TeV sources

Milagro extended sources

1-year observation


miniHAWC

Survey Sensitivity

4 m

in/fo

v

7 m

in/fo

v1500 hrs/fov1500 hrs/fov


miniHAWC

Detector Sensitivity (Single Location)

miniHAWCHAWC

GLAST

EGRET

Crab Nebula

WhippleVERITAS/HESS

Current synoptic instruments

MiniHAWC Jordan Goodman Beijing – June 2006 Jordan Goodman University of Maryland mini- High...

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