Technical Specifications.pdf

Electron-Ion Collider, Brookhaven National Laboratory

Doc No. EIC-DET-SPC-019 Author: Oleg Eyser Effective Date: April 29, 2024 Review Frequency: N/A

Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01

TECHNICAL SPECIFICATION

for the

Forward Hadronic Calorimetry SiPMs

Quality Classification: A-3

Prepared By:

_________________________________ Date: __________________

Oleg Eyser, Senior Physicist

Reviewed By:

Edward Cheswick, Quality Representative

Maggie Haviland, Procurement Liaison Engineer

Chuck Schaefer, ESH Manager

Approved By:

Elke Aschenauer, Level 2 Manager

DocuSign Envelope ID: 036D3D8B-46A7-4FD2-8960-12B2030D8B02

4/29/2024

4/29/2024

5/1/2024

4/29/2024

5/1/2024

Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01

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Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01

REVISION HISTORY

Revision # Effective Date Summary of Change

00 1/31/2024 Initial Release

01 4/29/2024 Total count of SiPMs removed, 3 mm x

3 mm SiPMs added, pre-production tests removed

Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01

TABLE OF CONTENTS

1 SCOPE

1.1 Background

2 APPLICABLE DOCUMENTS

3 REQUIREMENTS

3.1 Technical/Performance Characteristics

3.2 Environment, Safety and Health

3.3 Marking and Serialization

3.4 Packaging/Shipping

3.5 Storage

4 VERIFICATION

4.1 Classification of Inspections

4.1.1 Acceptance Tests

Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01

LIST OF ACRONYMS

ATP Acceptance Test Procedure

BNL Brookhaven National Laboratory

BSA Brookhaven Science Associates

EIC Electron-Ion Collider

QA Quality Assurance

SiPM Silicon Photomultiplier

SOW Statement of Work

Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01

Technical Specification for the Forward Hadronic Calorimetry SiPMs

1 SCOPE

This specification defines the technical requirements for the Silicon Photomultipliers (SiPMs) for the longitudinally segmented Forward Hadronic Calorimeter (LFHCal) of the Electron-Ion

Collider (EIC) at Brookhaven National Laboratory (BNL) managed by Brookhaven Science

Associates (BSA).

1.1 Background

The EIC Project will design, build, and install the accelerator hardware for a new electron storage ring, an electron injector, and modifications to the hadron ring required to produce an electron-ion collider and infrastructure. It will include one interaction region and one detector. The facility is designed to meet requirements to ensure high reliability and availability for the user program.

The EIC physics detector will provide an almost 4 coverage in tracking, particle identification, electromagnetic and hadronic calorimetry. The hadronic calorimeter in the forward (hadron-going) endcap is of a particular importance, to measure highly energetic particle jets with a sufficient energy resolution, isolate jet neutral components (neutrons and KL particles), complement tracking and electromagnetic calorimetry in particle flow algorithms, and be an integral part of the detector solenoid flux return path.

LFHCal makes use of a SiPM-on-tile technology, where every one of the sixty-five scintillating tiles composing a calorimeter tower has a dimple for its own Silicon Photomultiplier (SiPM) sensor.

2 APPLICABLE DOCUMENTS

None

3 REQUIREMENTS

3.1 Technical/Performance Characteristics

The table below specifies the requirements of the SiPMs for the EIC Forward Hadronic

Calorimeter. The table summarizes the results of the bench test evaluation of several types of

SiPMs available on the market, irradiation studies, as well as the GEANT Monte-Carlo simulations. An active area of 1.3 mm x 1.3 mm (type a) is sufficient to collect the light produced

Doc No. EIC-DET-SPC-019 Author: Oleg Eyser Effective Date: Review Frequency: N/A

Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01 in a small scintillator tile. In a high radiation environment, an active area of 3 mm x 3 mm (type

b) is desirable to improve the signal over noise ratio. A small pixel size is important to increase the dynamic range. Peak sensitivity matches the emission spectrum of the scintillating tiles. High quantum efficiency is critical to increase the photo statistics. Small operating voltage spread within a batch allows one to simplify a bias voltage setup in the experiment.

Parameter Specification

Active area

(a) 1.3 mm x 1.3 mm min.

(b) 3 mm x 3 mm min.

Pixel size 15 micron max.

Package type Surface mount

Peak sensitivity 450 – 470 nm

Photon Detection Efficiency (PDE) Greater than 25% at the peak value

Gain Greater than 3*105

Dark Count Rate (DCR) Less than 500 kHz

Temperature coefficient of operating voltage (Vop =

VBR + 5V, where VBR is the breakdown voltage) Less than 40 mV/°C

Direct crosstalk probability Less than 1%

Vop variation within a tray Less than 0.1 V between min and max values

Fill factor Greater than 40%

Protective layer Epoxy resin with a refractive index [1.50 – 1.60]

3.2 Environment, Safety and Health

Identification of hazards and their mitigation are required during all stages of the life of the

Equipment including; installation, commissioning, operation, maintenance, and repair.

Identification of means to eliminate or manage each hazard shall be provided based on the following hierarchy:

• Eliminate the hazard, or manage the hazards in the following hierarchy;

• Substitute with something less hazardous, or

• Engineer – mitigate the severity of the hazard, or

• User Personal Protective Equipment (least desirable).

3.3 Marking and Serialization

Each SiPM sensor shall have a serial number on its tray package. This serial number shall be traceable to the Vop measurement data provided for every SiPM in a tray.

Doc No. EIC-DET-SPC-019 Author: Oleg Eyser Effective Date: Review Frequency: N/A

Specification Title: Technical Specification for the Forward Hadronic Calorimetry SiPMs Revision: 01

3.4 Packaging/Shipping

SiPMs shall be packaged in trays to allow usage of a pick and place machine during calorimeter tower assemblies. The number of SiPMs per tray is to be defined in a communication with the

Contractor. Trays shall be shipped in a vacuum sealed container to avoid possible adverse effect(s) of high humidity on the protective resin transparency.

3.5 Storage

Storage at the manufacturing facility shall be done in vacuum sealed containers, directly following

SiPM production, to avoid any adverse effects mentioned in section 3.4.

4 VERIFICATION

Appropriate inspections/tests shall be performed to ensure SiPMs conform to all requirements in section 3 of this specification.

4.1 Classification of Inspections

Items covered by this specification shall be subjected to the following tests to determine compliance with all applicable requirements:4.1.1 Acceptance Tests

4.1.1.1 Acceptance Tests Performed at Contractor - The Contractor shall submit ATPs for BSA written approval that are in accordance with this specification and all reference documents noted herein. The SiPMs shall be tested at the Contractor’s facility, Contractor’s subcontractor facility, or pre-approved BSA collaborator to demonstrate compliance with this specification. All data shall be documented and delivered to BNL for review prior to acceptance. In addition, the following tests shall be conducted on SiPMs by the Contractor in accordance with the ATP, prior to delivery to BNL:

• Dimensional Measurement – Dimensions of the SiPMs shall be measured for conformance to the technical requirements. The list of required dimensions that shall be measured will be indicated in the BSA approved ATP.

• Voltage – Each tray shall be accompanied by a list of measured breakdown voltages for each SiPM as measured by the Contractor.

4.1.1.2 Acceptance Tests Performed at BNL – To be performed at BNL or a potential third-party testing facility. Five (5) percent of the received articles will be tested at random regarding their size and breakdown voltage. These test samples will be compared against the measurements provided by the Contractor. The acceptance of the shipment will depend upon these results and their compliance with the specifications listed in 3.1.