STATEMENT OF WORK.pdf

ATTACHMENT A, STATEMENT OF WORK (SOW):

Integrated Detector Cooler Assembly with 2x8 Pixel HgCdTe APD Photodiode Array

Statement of Work (SOW) Integrated Detector Cooler Assembly (IDCA) with 2x8 Pixel Mercury Cadmium Telluride (HgCdTe) Linear Mode Photon Counting Avalanche Photodiode (APD) Array

Rev. 1, 1/5/2022

I. Background NASA Goddard Space Flight Center (GSFC) is developing a swath mapping lidar for Earth and planetary science investigations under an Instrument Incubator Program (IIP) from the Earth Science Technology Office. One of the major subsystems of the lidar is an integrated detector cooler assembly (IDCA) with a 2x8 pixel mercury cadmium telluride (HgCdTe) avalanche photodiode (APD) array and the support electronics in a mini Stirling cryo-cooler (also known as integrated detector- -cooler assembly, or IDCA). The HgCdTe APD array must be able to detect single photon high efficiency at 1030 and 1550 nm laser wavelengths with linear mode photon counting (LMPC) outputs. The devices must be space radiation tolerant for a multi-year planetary mission. Leonardo DRS Electro-Optical Infrared Systems in Dallas Texas (DRS from here on) is making such a device under a NASA Maturation of Instruments for Solar System Exploration (MatISSE) program (80GSFC20C0027). The IIP program plans to leverage on the investment by the MatISSE program and procure a second unit of the IDCA with minor modifications. This contract is to procure a second IDCA unit based on the same design and using residual components from the MatISSE program.

II. Objective The objective of this procurement is for DRS to fabricate, test, and deliver a second unit of the IDCA, which is identical to that under NASA contract 80GSFC20C0027 but with a larger size cold shield.

III. Period of Performance The total period of the performance for this acquisition is 9 months after receipt of order.

IV. Technical Requirements

Specifications of the IDCA:

Verified by the unit design and component selections:

Focal plane array: 2x8 pixel HgCdTe APD array with guard ring.

Pixel dimension: 64x64 m2/pixel at 64 m pitch.

Fill factor without microlens array: 40%.

Microlens array: 60 micron above the APD array to increase the fill factor to 100%.

Read-out integrated circuit (ROIC): built-in transimpedance preamplifies.

ROIC output: total 16 output channels, one for each pixel.

Cryo-cooler: mini-cryo coolers designed and verified for multi-year space application.

IDCA: integrated assembly with the above detector and cooler with the control electronics, detector control electronics, and analog signal buffer and line drivers.

IDCA operation environment: capable of operation in space environment (vacuum, weightless, any orientation)

ATTACHMENT A, STATEMENT OF WORK (SOW):

Integrated Detector Cooler Assembly with 2x8 Pixel HgCdTe APD Photodiode Array

Cold shield numerical aperture: f/4.8 minimum requirement and f/3.2 goal

Verified by test results of earlier devices from the same fabrication process:

HgCdTe APD quantum efficiency: 90% from 1.0 to 4.3 m wavelength.

HgCdTe APD gain normalized dark current: <50,000 electrons/s.

APD gain excess noise factor: <1.3.

FPA radiation damage tolerance, transient event: no damage and recovery within <1s.

FPA radiation damage tolerance, accumulated fluence: 7e10/cm2 (10 krad(Si)) 55 MeV proton irradiation.

Verified by tests and datasheet of the optical windows and the cold filters from the suppliers:

APD gain: 1 to >500 (goal 1000), adjustable via the bias voltage from 0 to 12 volts.

FPA operating temperature: from 77 K to 110 K.

Median photon detection efficiency: >30% (50% goal) at <7 MHz false event rate.

Single photon detection output pulse width: <8 ns full width at half maximum (FWHM).

Signal to noise ratio of the pulses from single photon detections: >10.

Pixel operability: >90% (100% goal).

Timing jitter: < 2 ns root-mean-squares (rms), leading edge single photon detection.

Cryo-cooler cold finger temperature: 100 K.

Cryo-cooler heat sink (rejection) temperature range: -30C to +50C.

Cryo-cooler optical window transmission: >95%, at 1 and 1.55 m wavelength.

Cold filter transmission: >90% over 1.02-1.09 m, and 1.47-1.65 m transmission bands.

Cold filter out-of-band blocking: optical density (OD) of 6.

Cryo-cooler optical window transmission: >95% over the above wavelength ranges.

IDCA vibration test: 14 G rms for 1 minute, all three axes.

IDCA net mass: <1.0 kg (not including the mounting bracket and plate).

IDCA dimension: 4.0x4.6x3.3 inches or smaller.

IDCA electrical power: <8.0 W with the FPA at 110 K and heat sink at 25C, in ambient atmosphere.

Deliverables:

1.0. One IDCA with a 2x8 pixel LMPC HgCdTe APD array in a mini-Stirling cryo-cooler, fully tested.

2.0. Test data at DRS and relative datasheets from the suppliers