HAWC High Energy Upgrade with a Sparse Outrigger Array t h 3 5 - - PowerPoint PPT Presentation

HAWC High Energy Upgrade with a Sparse Outrigger Array

3 5

t h

I n t e r n a t i

• n

a l C

• s

m i c R a y C

• n

f e r e n c e 2 1 7 V i k a s J

• s

h i a n d A r m e l l e J a r d i n

• B

l i c q f

• r

t h e H A W C C

• l

l a b

• r

a t i

• n

Vikas Joshi, HAWC Outriggers, ICRC 2017 2

Location : Puebla , Mexico Altitude : 4100 m above sea level Area : 22000 m2 Completed in March 2015 with 300 Water-Cherenkov Detectors.

Pico de Orizaba

The High-Altitude Water Cherenkov Observatory (HAWC)

Vikas Joshi, HAWC Outriggers, ICRC 2017 3

Operates day and night. Large field of view : ~ 2 steradians Energy range : 0.1 - 100 TeV

γ/ p

Particle shower

The High-Altitude Water Cherenkov Observatory (HAWC)

+

Vikas Joshi, HAWC Outriggers, ICRC 2017 4

>10 TeV Showers at HAWC

Footprint of a ~10 TeV shower is comparable to the main HAWC array.

Vikas Joshi, HAWC Outriggers, ICRC 2017 5

Edge dominant

>10 TeV Showers at HAWC

Vikas Joshi, HAWC Outriggers, ICRC 2017 6

Motivation for Outriggers

• When

shower core falls

• utside of the main array, it

can be mis-reconstructed as a lower energy shower closer to the array.

• Which eventually affects :

➢ Direction reconstruction. ➢ Energy reconstruction. ➢ Gamma hadron separation.

So we have an uncertainty on the location of the shower. Main HAWC Array

True shower Mis-reconstructed shower

Vikas Joshi, HAWC Outriggers, ICRC 2017 7

So how can we deal with this?

Vikas Joshi, HAWC Outriggers, ICRC 2017 8

So how can we deal with this?

Vikas Joshi, HAWC Outriggers, ICRC 2017 9

So how can we deal with this?

Vikas Joshi, HAWC Outriggers, ICRC 2017 10

HAWC Outrigger Array Description

• A sparse outrigger array around the main HAWC array.
• It is mainly optimized for energies > 10 TeV.
• Increase in instrumented area by a factor of 4-5.
• Consist of 350 outrigger tanks, with one Hamamatsu R5912 8" PMT in each of them.

Vikas Joshi, HAWC Outriggers, ICRC 2017 11

FADC Electronics for Outrigger Nodes

tank from the main array

• utrigger tank

zone delimitation node

5 sections of 70 outriggers. For each Node:

• 3 FlashADC cards:

➢ 12 bit FADC sampled at 250 MHz. ➢ Flexible digital multiplicity trigger.

• 24 channels per card, 1 channel per
• utrigger.

Flash Adc eLectronics for the Cherenkov Outrigger Node.

Vikas Joshi, HAWC Outriggers, ICRC 2017 12

Calibration of Outrigger PMTs

• Full calibration of the PMT using

➢ A laser λ = 398 nm. ➢ HV = 1500 V. ➢ A 6db attenuator.

Time resolution Amplitude resolution

Vikas Joshi, HAWC Outriggers, ICRC 2017 13

Sample Size = 4 ns

Typical Example Event

Vikas Joshi, HAWC Outriggers, ICRC 2017 14

Typical Event Reconstruction

Vikas Joshi, HAWC Outriggers, ICRC 2017 15

Fiducial Cuts for Outriggers

HAWC300 = 70 m HAWC+OR = 170 m

Vikas Joshi, HAWC Outriggers, ICRC 2017 16

Core Resolution Comparison with and without Outriggers

• The data points are at the 68% containment area value of (fit core – true core) histogram.
• Fiducial cuts:

1> Energy Range : 0.3 TeV to 300 TeV. 2> Maximum zenith angle : 45 degree. 3> Minimum Number of Main Array Tanks Hit = 20.

Vikas Joshi, HAWC Outriggers, ICRC 2017 17

Trigger Effective Area Vs. Simulated Energy

• MA Trigger

40 Channels. →

• OR Trigger

At least 2 OR in any sub-section. →

• MA+OR Trigger

MA trigger and OR trigger both, as well as only MA trigger. →

• Area

Area of the simulated showers. →

• Zenith angle < 13 degree.

Vikas Joshi, HAWC Outriggers, ICRC 2017 18

Conclusions

• What we will achieve with outriggers?

➢ More accurate determination of the core position (above 7TeV ~75% improvement). ➢ Increased trigger effective area above a few TeV by a factor of ~5.

• Current status:

➢ The installation of outriggers is currently taking place. ➢ Software for combined analysis of outrigger + main array is being developed. ➢ Testing of FALCON with outrigger tanks is being performed on site.

• Future plan:

➢ Merging of the outrigger system with the central readout system (late summer). ➢ Deployment of full outrigger array by the end of 2017. ➢ Start taking data from the beginning of 2018, enhanced sensitivity above 10 TeV.

Vikas Joshi, HAWC Outriggers, ICRC 2017 19

Thank You for Your Attention

Vikas Joshi, HAWC Outriggers, ICRC 2017 20

Back Up Slides Back Up Slides

Vikas Joshi, HAWC Outriggers, ICRC 2017 21

On Site Measurements

Vikas Joshi, HAWC Outriggers, ICRC 2017 22

On Site Measurements

Measurement of the rate for a multiplicity 2 and 4, amongst 4 similar tanks.

Vikas Joshi, HAWC Outriggers, ICRC 2017 23

Trigger and Not Trigger Comparison for Outriggers

• Total OR Hit

The total number of Outrigger got hit. →

• Triggered OR Hit

The number of Outrigger got readout. →

• Left panel is showing the profiles of Total OR hit and Triggered OR Hit with simulated

energy.

• Right panel is showing the subtraction of these two profiles.

Vikas Joshi, HAWC Outriggers, ICRC 2017 24

Outrigger Trigger Ratio with Energy

• N_total

Total number of outrigger got hit. →

• N_triggered

Total number of outrigger readout. →

Vikas Joshi, HAWC Outriggers, ICRC 2017 25

Core Resolution Comparison with and without Outirggers

• The data points are at the 68% containment area value of (fit core – true core) histogram .
• Fiducial cuts:

1> Energy Range : 0.3 TeV to 300 TeV. 2> Maximum zenith angle : 45 degree.