OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Space Technology The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: The primary objective is to develop commercial products that specifically permit infrared detector characterization lab users to recover, purify and reliquefy neon gas, at the small scale (<10 liters per day of liquid neon), back into a cryogenic liquid intended for use in pour fill cryogenic dewars, and, thereby, reducing the burden of acquiring additional liquid neon. DESCRIPTION: Characterizing infrared focal plane arrays is ideally done with the test part in a pour fill dewar that uses liquid cryogens, rather than a closed-cycle system which potentially contributes noise to the test system and limits ones ability to perform focal plane array characterization at a remote facility such as a radiation source. Liquid neon is a near ideal liquid cryogen for this role. It boils at 27.5 K, which is well below liquid nitrogen and, more specifically, below where typical high performance infrared sensors operate, including long wave infrared detectors. Liquid neon also has over 40 times the refrigerant capacity per unit volume than liquid helium.[1] During a detector characterization, these two properties translate into fewer liquid cryogen transfers into the dewar using liquid neon, leaving more time for characterization. This is an absolutely indispensable advantage in the highly unique circumstance of a remote focal plane array radiation tolerance experiment, where access to the radiation source is strictly limited, rarely available and expensive, and the part must be kept cold for over a week at a time. Unfortunately, due to some unusual circumstances, liquid neon is very expensive and difficult to come by. This is because 70% of the neon produced in the world is used in the growing semiconductor chip manufacturing industry, where argon-flourine-neon excimer pulsed lasers are the workhorse source for deep ultraviolet lithography and the ultra-high purity neon (~99.9999%) used in them must be replenished every two weeks. Additionally, neon production occurs mainly as a byproduct of nitrogen generation via cryogenic distillation of air, a technique that happened to be perfected in the Ukraine where grain production requires large amounts of nitrogen for fertilizer. Given the current difficulties in the Ukraine and its diminished production capacity and the growing use of neon in semiconductor manufacturing, the price of liquid neon has risen to roughly $3000/liter, a 600% increase since 2014. Furthermore, there is currently a single domestic distributor of liquid neon, Linde Corp. However, there is a straightforward path to alleviating some of the hardship associated with the use of liquid neon for characterizing focal plane arrays. The technology to recover and liquefy certain gases, such as helium, at the small scale (~25 liters per day) has been commercially available for nearly a decade and has had a major impact on research and medical institutions ability to experiment, or run their instruments, at cryogenic temperatures. For example, Quantum Design North America, located in San Diego, CA, already offers a complete line of helium liquifiers and helium recovery, storage and purification systems, which allows users to recover and liquefy the exhausted helium gas currently being lost from the normal boil off and helium transfers to cryogenic instruments.[2] This technology alleviates the user's dependence on cryogen suppliers and lessens the impact of rising costs and undependable supply, as well as helps preserve a precious natural resource which is vital to scientific research and medical treatment. With some modification, a similar approach can now likely be adopted for the small scale (<10 liters per day) recovery and reliquefication of neon used in scientific research. In fact, reliquefication of exhausted neon gas was already demonstrated at the laboratory scale (~3 liters per day) in the early 1990s, but the technique was never adopted, likely due to cost and availability of liquid neon.[3] PHASE I: Awardee(s) will perform initial technical feasibility study and develop plans for a system to recover, purify and reliquefy neon gas at the small scale for use in a detector characterization lab, or semiconductor device fa. System should be similar to existing helium reliquefiers that are currently commercially available (e.g. Quantum Design ATL160L, etc.) but with a smaller capacity of no more than 50 liquid liters and with the capability to be transportable to remote experiments. Feasibility study should also consider recovery and purification of neon from contaminated lasing gas discharged by excimer lasers used for semiconductor processing. PHASE II: Awardee(s) will build, characterize and deliver a prototype system to recover, purify and reliquefy neon gas at the small scale for use in a detector characterization lab. System should be similar to existing helium reliquefiers that are currently commercially available (e.g. Quantum Design ATL160L, etc.) but with a smaller capacity of no more than 50 liquid liters and with some capability to be transportable to remote experiments. System characterization should show any applicability to recovery and purification of neon from contaminated lasing gas discharged by excimer lasers. PHASE III DUAL USE APPLICATIONS: If a successful prototype is developed, then prototype will be commercialized to improve availability of liquid neon in DOD focal plane characterization laboratory and similar domestic laboratories across the US. REFERENCES: Hammond, C. R. "The Elements, in Handbook of Chemistry and Physics, 81st edition.", CRC press, p. 19, ISBN 0849304814.; Quantum Design Inc. "Helium Liquefiers, Purifiers and Recovery Systems." Mar 2023, https://qdusa.com/products/helium_liquefiers.html; Francavilla et al., Simple apparatus for the liquefaction of neon directly into a research Dewar, Rev. Sci. Instrum. 64, 2023, 1993.; KEYWORDS: neon, cryogenics, recovery, purification, reliquefication, infrared detectors, excimer lasers
