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 t h 3 5 I n t e r n a t i o n a l C o s m i c R a y C o n f e r e n c e 2 0 1 7 V i k a s J o 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 o r t h e H A W C C o l l a b o r a t i o n

The High-Altitude Water Cherenkov Observatory (HAWC) Pico de Orizaba Location : Puebla , Mexico Altitude : 4100 m above sea level Area : 22000 m 2 Completed in March 2015 with 300 Water-Cherenkov Detectors. Vikas Joshi, HAWC Outriggers, ICRC 2017 2

The High-Altitude Water Cherenkov Observatory (HAWC) γ/ p Operates day and night. Large field of view : ~ 2 steradians Energy range : 0.1 - 100 TeV Particle shower + Vikas Joshi, HAWC Outriggers, ICRC 2017 3

>10 TeV Showers at HAWC Footprint of a ~10 TeV shower is comparable to the main HAWC array. Vikas Joshi, HAWC Outriggers, ICRC 2017 4

>10 TeV Showers at HAWC Edge dominant Vikas Joshi, HAWC Outriggers, ICRC 2017 5

Motivation for Outriggers ● When shower core falls True shower outside of the main array, it Mis-reconstructed shower can be mis-reconstructed as a lower energy shower closer to the array. Main HAWC Array So we have an uncertainty on the location of the shower. ● Which eventually affects : ➢ Direction reconstruction. ➢ Energy reconstruction. ➢ Gamma hadron separation. Vikas Joshi, HAWC Outriggers, ICRC 2017 6

So how can we deal with this? 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

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 10

FADC Electronics for Outrigger Nodes tank from the main array outrigger 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 outrigger. F lash A dc e L ectronics for the C herenkov O utrigger N ode. Vikas Joshi, HAWC Outriggers, ICRC 2017 11

Calibration of Outrigger PMTs ● Full calibration of the PMT using ➢ A laser λ = 398 nm. ➢ HV = 1500 V. ➢ A 6db attenuator. Amplitude resolution Time resolution Vikas Joshi, HAWC Outriggers, ICRC 2017 12

Typical Example Event Sample Size = 4 ns Vikas Joshi, HAWC Outriggers, ICRC 2017 13

Typical Event Reconstruction Vikas Joshi, HAWC Outriggers, ICRC 2017 14

Fiducial Cuts for Outriggers HAWC300 = 70 m HAWC+OR = 170 m Vikas Joshi, HAWC Outriggers, ICRC 2017 15

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 16

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 17

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 18

Thank You for Your Attention Vikas Joshi, HAWC Outriggers, ICRC 2017 19

Back Up Slides Back Up Slides Vikas Joshi, HAWC Outriggers, ICRC 2017 20

On Site Measurements Vikas Joshi, HAWC Outriggers, ICRC 2017 21

On Site Measurements Measurement of the rate for a multiplicity 2 and 4, amongst 4 similar tanks. Vikas Joshi, HAWC Outriggers, ICRC 2017 22

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 23

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 24

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. Vikas Joshi, HAWC Outriggers, ICRC 2017 25