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66 -- HELIUM 3 NEUTRON DETECTORS AND CHARGE AMPLIFIERS SOL 40SBNB860073 DUE 052298 POC Linda Shariati, Contract Specialist, (301) 975-5053 WEB: NIST Contracts Homepage, http://www.nist.gov/admin/od/contract.htm. E-MAIL: NIST Contracts Office, Contract@nist.gov. This procurement is being conducted in accordance with Federal Acquisition Regulation (FAR) 13.5 entitled, "Test Program for Certain Commercial Items". This subpart of the FAR authorizes the use of simplified procedures for the acquisition of supplies and services in amounts greater than the simplified acquisition threshold. The Government intends to acquire 100 helium 3 filled neutron detectors and 100 charge amplifiers on a sole source basis from Eurisys Mesures, ZA de l'Observatoire, 4 avenue de Frenes, F-78067 St. Quentin Yvelines, France. The detectors and amplifiers are components of the Disk Chopper Spectrometer owned by NIST. This spectrometer has been tailored to meet the Governments requirements. The Government currently owns 840 detectors and 880 amplifiers. The new detectors and amplifiers must be mechanically and neutronically identical to the previously purchased components since they will all be installed on the Disk Chopper Spectrometer at the NIST Center for Neutron Research. Information regarding this spectrometer can be located on the Internet at http://rrdjazz.nist.gov/dcs.html. The detector and amplifiers must meet the requirements identified below. The detector specifications include: overall length 522 mm; overall end diameter 25 mm; overall section 12.5 x 31.5 mm; electrical output right-angle HN; wall thickness 0.5 mm; wall material of stainless steel; active length of 400 mm; active cross section 11.5 x 30.5 mm; and Helium 3 pressure of 6 bar. The detector operating characteristics include: mean operating voltage 1050 V; gas amplification spread of plus or minus 5 percent; plateau length of 300 V; plateau slope of 0.7 percent per 100 V; FWHM resolution of 10 percent; jitter time of 0.3 microseconds; pulse rise time of 0.6 microseconds; background count rate of 8 counts per hour; Yield of detection -- over active thickness (11.5 mm) 60 percent for 1.8 angstrom neutrons; 87 percent for 4 angstrom neutrons. The manufacturing process was developed to enable the use of standard circular tube end piece parts. Eurisys Mesures holds a patent on this process. Cylindrical detectors will not meet the Government's need. The Charge Amplifiers' specifications include: dimensions(connectors not included) 100 x 50 x 25 mm; weight of 212 g. The amplifiers will be utilized for Time-of-Flight measurements. The amplifier electrical properties include: integrating time constant of 1 microsecond; differentiating time constant of 0.8 microseconds; sensitivity of 10 volts per picoCoulomb; equivalent capacitance of 0.1 picoFarad; FWHM noise charge (at the input) of 10 to the power of minus 15 Coulomb; resolving time of 5 microseconds; threshold value of 150 mV; TTL compatible logic pulses; cable length capability of 15m; mean spread of time delay between analog and logic pulses of 0.6 microseconds; and, drift of sensitivity versus temperature of 0.1 percent per degree Celsius. The items shall be under warranty for a period of one year. These items shall be delivered six months after receipt of the order. The items shall be delivered to the National Institute of Standards and Technology (NIST), Gaithersburg, Maryland. FOB Destination. As a part of this requirement, the Government intends returning 20 to 25 geometrically identical detectors and anticipates a credit for this return to be applied to the purchase identified herein. The Government will request a written quotation from Eurisys Mesures, Inc. The anticipated award date is June 5, 1998. NOTES: 1. This document must be created in WordPerfect for Windows for use in CBDNet. 2. A complete list of Classification Codes is on the Internet, reachable at the address: http://cbdnet.access.gpo.gov/class.html 3. The office address in CBDNet is automatic, therefore, any special addresses (other than our standard office address) must be contained in the description. Reviewer's Initials:__ __ __ __ (0135)

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