Status of the SHMS Aerogel Detector

S. Ali, M. Carmignotto, T. Horn, A. Mkrtchyan, H. Mkrtchyan, V. Tadevosyan, R. Trotta, R. Uniyal, A. Vargas

Hall C Winter Meeting, Jefferson Lab, Newport News, VA 20-21 January 2017

❑ SHMS Aerogel Cherenkov detector: 1 diffusion box, 4 exchangeable aerogel trays of indices 1.03, 1.02, 1.015, 1.011

SHMS Aerogel Detector Overview

❑ Built with support of NSF MRI PHY-1039446 by a consortium led by CUA

➢ Consortium: CUA, University of South Carolina, Florida International University, Yerevan, JLab

Construction is complete and detector has been installed in the SHMS

The four aerogel refractive indices cover the momentum range required by the experiments

➢ Installed between Heavy Gas Cherenkov and 2nd scintillator plane

➢ Covers momentum range from 2-6.5 GeV/c

Pedestal and Single Electron Peak distributions (Fit values were used to calculate number of PE)

SHMS Hodoscope Trigger Signal: (S1).AND.(S2X)

Signals time distribution in fADC: Channel 14-32 for reals, Channel 52-70 for accidentals

S1 = (S!X).AND.(S1Y) S1X = (S!XL).AND.(S!XR)S2X = (S2XL).AND.(S2XR)

SHMS Aerogel detector readinessDetector has been tested with cosmics using the SHMS hodoscope arrays as trigger

All PMT channels are counting – hardware is ready

Summed number of photoelectrons

n=1.030 n=1.015

SHMS Aerogel detector performance

Aerogel trays perform as expected – detector is ready for beam

Summed number of photoelectrons

Detector has been tested with cosmics using the SHMS hodoscope arrays as trigger

➢ Reflector material is different for the two indices shown (higher reflectivity for n=1.015)

SHMS Hodoscope Trigger Signal: (S1).AND.(S2X)

S1 = (S!X).AND.(S1Y) S1X = (S!XL).AND.(S!XR)S2X = (S2XL).AND.(S2XR)

Inserts show accidentals

Matsushita aerogel previously used in BLAST experiment

JFCC new aerogel

Millipore reflectorGORE reflector

SHMS Aerogel Detector Performance – prior to beam operations

❑ Details available in: Nucl. Instrum. Meth.A842 (2017) 28-47

Lines denote expected light output

Signal position dependence also as expected

Insight from performance tests: optimizations

Reflector has a substantial impact on light collection – in particular for lowest refractive aerogel indicesWork was done with the help of graduate, undergraduate and high school students at CUA and Jlab: Alex Dittmann (UIUC), Nathaniel Hlavin (CUA), Laura Rothgeb (CUA), Salim Roustom (Marshall HS), Jonathan Castellanos (FIU)

SHMS Aerogel Detector – Commissioning plan (for beam tests in February-April 2017)

❑ Analysis software: test with full analysis framework - collaboration

❑ Readout: plug into full SHMS system when ready – support from Hall C required➢ Currently using smaller scale system similar to full SHMS readout

➢ Analysis code has been adapted to SHMS❑ Final preparation for operation with beam: install SP-30 aerogel tray – support from Hall C required

➢ initial refractive index needed by early experiment run group

Phase 1. For early stage of SHMS commissioning, when only all magnets and hodoscope planes would be operational, but without rolled-in tracking system and PID detectors; and

Phase 2. With tracking system (Drift chambers, spectrometer optics and tracking reconstruction algorithm) and Particle Identification detectors (gas Cherenkov and Calorimeter) passed at least first preliminary stage of commissioning.

SHMS Aerogel Detector Operations

❑ Operations Manual has been written to specify detector operations. Includes for example,

➢ Tray Exchange

➢ Servicing PMTs

❑ Responsible Personnel: CUA and Yerevan will be responsible for maintenance and control

➢ CUA: S. Ali, M. Carmignotto, A. Mkrtchyan, T. Horn

➢ Yerevan: A. Asaturyan, H. Mkrtchyan, V. Tadevosyan

Configuration changes require coordination with Hall C work coordinator

➢ Precaution - tiles are in tray and its positioned at 18 one bump can damage all