Jordan Goodman HAWC Review - December 2007 HAWC A Wide-Field Gamma-Ray Telescope Jordan A. Goodman University of Maryland

Jordan GoodmanHAWC Review - December 2007

HAWCHAWC A Wide-Field Gamma-Ray TelescopeA Wide-Field Gamma-Ray Telescope

Jordan A. GoodmanJordan A. Goodman

University of MarylandUniversity of Maryland


Outline of Our PresentationOutline of Our Presentation

• Overview plus Milagro history (Jordan Goodman) (15min)Overview plus Milagro history (Jordan Goodman) (15min)• Milagro Observations (Gus Sinnis) (30 min)Milagro Observations (Gus Sinnis) (30 min)• HAWC Science (Brenda Dingus ,Julie McEnery) (45 min)HAWC Science (Brenda Dingus ,Julie McEnery) (45 min)• HAWC Design & Performance (Andy Smith, Vlasios Vasileiou) HAWC Design & Performance (Andy Smith, Vlasios Vasileiou)

(1hr)(1hr)• HAWC Technical Engineering Design (Michael Schneider, Jim HAWC Technical Engineering Design (Michael Schneider, Jim

Linnemann, Andy Smith, John Matthews) (1hr)Linnemann, Andy Smith, John Matthews) (1hr)• Site & Mexican Collaboration (Alberto Carraminana) (30min)Site & Mexican Collaboration (Alberto Carraminana) (30min)• Construction Plan, Management & Budget (Jordan Goodman) Construction Plan, Management & Budget (Jordan Goodman)

(45 min)(45 min)• Education/Outreach & Wrap Up- (Jordan Goodman) (15 min)Education/Outreach & Wrap Up- (Jordan Goodman) (15 min)


Why are we here?Why are we here?

• HAWC is an intermediate scale experiment (<$10M)HAWC is an intermediate scale experiment (<$10M)• With the passing of SAGENAP there is no standing With the passing of SAGENAP there is no standing

committee with the expertise to review proposals of committee with the expertise to review proposals of this scalethis scale

• It is too big (and complex) to be handled by standard It is too big (and complex) to be handled by standard mail-in reviewsmail-in reviews

• If experiments like this are to funded they need to If experiments like this are to funded they need to come to the January NSF PA panel with a strong come to the January NSF PA panel with a strong recommendation from experts who can say:recommendation from experts who can say:– That there is a compelling science case– That it is technically feasible – That the cost estimate is reasonable


University Grant Program Report University Grant Program Report (approved by HEPAP)(approved by HEPAP)

• The Scientific Advisory GroupsThe Scientific Advisory Groups (SAGs) should regularize their role in reviewing (SAGs) should regularize their role in reviewing projectsprojects– Each SAG should actively monitor and prioritize the experiments and R&D

in its area. It should evaluate both physics goals and technical design. – The SAGs should report to P5, timing their reports so that they are available

to P5 when needed. – The SAGs should review all experiments with expected construction costs

above $5M, along with smaller ones seeking review. This includes both experiments that are affiliated with a U.S. laboratory and those that are not. Additional SAGs should be created as needed to cover all areas (taking care to avoid proliferation).

– HEPAP should establish mechanisms for prioritizing experiments whose cost is above $5M but below the P5 threshold. The prioritization process should take advantage of input from the SAGs and should reflect the

breadth of the field.


MilagroMilagro

• We proposed Milagro in We proposed Milagro in 19901990– ~$3M in an existing pond– With outriggers


MilagroMilagro


• It was before EGRET & It was before EGRET & BATSE BATSE – The Crab was the only

confirmed source

1990


MilagroMilagro



confirmed source• We expected to get 0.5We expected to get 0.5oo

angular resolution and 5angular resolution and 5/yr /yr on the Crabon the Crab

From Proposal


MilagroMilagro



confirmed source• We expected to get 0.5We expected to get 0.5oo

angular resolution and 5angular resolution and 5/yr /yr on the Crabon the Crab

• We built Milagro on budget We built Milagro on budget even though the funding was even though the funding was stretched out over 10 yearsstretched out over 10 years

Current Performance on the Crab

~9/yr with /h separation and weighting

~4/yr without /h separation and weighting

Pre-outriggerAng res = 0.70°

Post-outriggerAng res = 0.41°


MilagroMilagro

• Milagro was the first water-Cherenkov EAS detectorMilagro was the first water-Cherenkov EAS detector• We developed the technique for reconstruction and We developed the technique for reconstruction and

background rejectionbackground rejection• Using this first generation detector we: Using this first generation detector we:

– surveyed the Northern Sky at TeV energies– made the first detection of diffuse emission from

the galactic plane– found 4 new galactic TeV sources– observed the highest energy gamma rays every

seen (in excess of 100 TeV) – mapped diffuse emission of the Cygnus Region

TeV gamma rayHESS

Milagro


TeV TeV Rays: New Window on the Sky Rays: New Window on the Sky

TeV gamma rayHESS

Milagro


TeV TeV Rays: New Window for the Sky Rays: New Window for the Sky

TeV gamma ray

HESS


What we learned from MilagroWhat we learned from Milagro

• The pond had the sensitivity we expectedThe pond had the sensitivity we expected• We could reconstruct shower directions to within ~0.4We could reconstruct shower directions to within ~0.4o o

with a single layer detector.with a single layer detector.• That you could use the deep layer to reject That you could use the deep layer to reject

background proton showers with high efficiency background proton showers with high efficiency • That gamma showers that hit the pond could be well That gamma showers that hit the pond could be well

reconstructed, but were often rejected as protons, so reconstructed, but were often rejected as protons, so we needed outriggers to reconstruct gammas that we needed outriggers to reconstruct gammas that were off the pondwere off the pond

• That you could operate a detector remotely with 95% That you could operate a detector remotely with 95% on timeon time


What would make Milagro better?What would make Milagro better?

• Being higher up in the atmosphereBeing higher up in the atmosphere– Much lower threshold– Better energy resolution

• Having a much bigger deep layerHaving a much bigger deep layer– Much better background rejection– Allow us to keep many more gammas that hit the

detector without rejecting them• Optical Isolation of the PMTsOptical Isolation of the PMTs

– Better timing which gives better angular reconstruction

– Better background rejection– Better Energy Resolution


HAWC Detector DesignHAWC Detector Design

From Milagro to HAWC:From Milagro to HAWC:• Increase Altitude to 4100 m from 2650 m Increase Altitude to 4100 m from 2650 m • Increase Area to 22,000 mIncrease Area to 22,000 m2 2 from 4,000 mfrom 4,000 m2 2

(top layer) or 2,200m(top layer) or 2,200m2 2 (bottom layer)(bottom layer)• Reuse 900 Milagro PMTs and front end Reuse 900 Milagro PMTs and front end

electronics electronics • Equipment Cost $7.4MEquipment Cost $7.4M• HAWC 15 x Sensitivity of Milagro:HAWC 15 x Sensitivity of Milagro:

• Improved /h Sep., better angle recon, better energy res., lower threshold

– HAWC: Detect Crab in ~ 1 day (5)– Milagro: Detect Crab in 3 months


HAWC Scientific GoalsHAWC Scientific Goals

• Constrain the Constrain the origin of cosmic raysorigin of cosmic rays via via HAWC’s HAWC’s observations of observations of -rays up to 100 TeV-rays up to 100 TeV from discrete from discrete sources and the Galactic plane.sources and the Galactic plane.

• Probe Probe particle accelerationparticle acceleration in extreme magnetic and in extreme magnetic and gravitational fields via gravitational fields via HAWC’s observations of HAWC’s observations of transient TeV sourcestransient TeV sources, such as gamma ray bursts , such as gamma ray bursts and supermassive black holes.and supermassive black holes.

• Explore Explore new TeV physicsnew TeV physics via via HAWC’s unbiased sky HAWC’s unbiased sky surveysurvey with a detection threshold of ~30 mCrab in with a detection threshold of ~30 mCrab in two years.two years.


HAWC Sensitivity is 15x HAWC Sensitivity is 15x Better than Milagro’sBetter than Milagro’s

e

(a)(a) Larger Effective Area at Lowest Larger Effective Area at Lowest EnergiesEnergies

(b)(b) Better Angular ResolutionBetter Angular Resolution

(c)(c) Improved Background RejectionImproved Background Rejection

=> 15 x improvement in flux => 15 x improvement in flux sensitivitysensitivity

=> 15=> 1522 x faster to observe same x faster to observe same flux flux

(a)

(b)

(c)

100 GeV 1 TeV 10TeV 100 TeV



Had

ron

Eff

icie

ncy

Ang

. R

es.

(deg

)

E

ff.

Are

a (m

2 )


HAWC Sensitivity to a Crab-like SpectrumHAWC Sensitivity to a Crab-like Spectrum

1 Crab

0.01 Crab

•HESS/VERITAS,HESS/VERITAS, MAGICMAGIC, , Whipple, Whipple, sensitivity in 50 sensitivity in 50 hours, (~0.2 sr/year)hours, (~0.2 sr/year)•GLASTGLAST sensitivity in sensitivity in 1 year (41 year (4 sr) sr)•HAWC, HAWC, MilagroMilagro, , sensitivity in sensitivity in 1 (dashed) and 5 1 (dashed) and 5 (solid) years (2(solid) years (2 sr) sr)•HAWC will do better HAWC will do better for hard & diffuse for hard & diffuse sourcessources


HAWC’s Field of ViewHAWC’s Field of View

= 2.6sr

= 1.8 sr


HAWC Detector DesignHAWC Detector Design

• 900 water tanks

• Tanks are 5 meter diameter and 4.3 meter deep

• Tanks cost $4.1k each (inc. shipping)

• One 8” PMT/tank

• Tank array covers area of 150m x 150m with 78% coverage

DAQ trailer

Road

HAWC Tank Array in GEANT 4


Tanks vs PondTanks vs Pond• Less expensiveLess expensive• Build incrementallyBuild incrementally

– Develop & debug as we are building

– Within 2 yrs HAWC will have 4x Milagro sensitivity

• Expandable, Reconfigurable & Expandable, Reconfigurable & upgradeableupgradeable

GEANT4 Simulation

Muon (thinned 1/50) produces up to 100s of pes depending on impact parameter

100 MeV ray (thinned 1/200) produces 1pe/60 MeV independent of impact parameter


Site Location is Sierra Negra, MexicoSite Location is Sierra Negra, Mexico



Documents

Jordan Goodman HAWC Review - December 2007 HAWC A Wide-Field Gamma-Ray Telescope Jordan A. Goodman University of Maryland