Requirement final.pdf

Statement of Requirements

TITLE: Radiation Imaging Spectrometer

I. BACKGROUND INFORMATION

The Materials Measurement Science Division of the Material Measurement Laboratory at the National Institute of Standards and Technology (NIST) supports materials science needs providing measurements for the determination of composition and properties, enabling the realization of new technologies, with state-of-the-art instrumentation, methods, models and software to accurately and precisely measure materials, and to perform basic measurement science research to support core capabilities and foster innovation. The MMSD has a critical need for a wide-area Radiation Imaging Spectrometer, which is a single-track-sensitive, high spatial resolution and time resolving imaging alpha/beta spectrometer used as an in-contact 2π-geometry ambient background and low-level environmental radioactivity measurement. The detector is needed for energy determination from individual alpha and beta tracks, and localization of the track point of origin at a 0.02 second or longer frame rate. The current problem at NIST is to develop and perform methods for extremely sensitive and resolving low-level ambient and environmental radiation to produce imaging spectrometry quantitation, imaging, and radiation type and energy identification. The issue being faced is that a preexisting radiation imaging spectrometer (ADVACAM MiniPIX) meets all criteria except that it has too small of a sensor area (14 mm x 14 mm) to accommodate direct-contact samples up to the size of 2.8 cm x 7.0 cm, nor can it measure full radiation field areas in one imaging live-time session that is larger than 14 mm x 14 mm, without the resulting measurements suffering live-time sample occlusion, vignetting, or detection efficiency loss.

II. SPECIFICATIONS

The Contractor shall provide one (1) wide-area radiation imaging spectrometer that meets or exceeds the following technical requirements:

System:

• The radiation imaging spectrometer shall be operable at ordinary room temperatures and standard atmospheric pressure in a relative humidity range of 30 % to 65 % while meeting all specifications.

• The radiation imaging spectrometer system shall produce measurements of radiation fields up to 0.2 alpha

·sec-1 · µm-2.

• The radiation imaging spectrometer shall be able to image individual alpha-particles and beta-particles as discrete tracks.

• The radiation imaging spectrometer system shall be able to distinguish the difference between individual alpha and individual beta tracks present in the same imaging session.

• The radiation imaging spectrometer system shall be able to determine the energy per discrete particle track, track by track. The radiation imaging spectrometer system shall be able to image of field of many tracks simultaneously while meeting the other specifications in this document.

• The radiation imaging spectrometer system shall be able to count the number of incident alpha-particles over a specified period of time, no matter where they occur on the sensor face, while also operating the detector in a mode that will produce track images.

• The radiation imaging spectrometer system shall be able to distinguish individual tracks whose time of incidence is separated by 0.1 second or longer, even if the position of incidence of multiple tracks overlaps.

• The nearby or overlapping incidence of one track shall not cause data (energy, size, location) of a previous track in that same location to be altered.

• Individual track positions shall be locatable within about 10 micrometers, which can be done at less than the pixel dimension by centroiding if each tracks is composed of a large number of pixels.

• Each incident alpha-particle detected shall produce a track feature in an image with a spatial resolution of no worse than 80 micrometers. For alpha-particle energies 3 MeV and above, an alpha-track image shall consist of at least 4 contiguous pixels in diameter along the minor axis of the track, preferably more to allow for subpixel centroiding.

• The radiation imaging spectrometer system shall be able to deconvolve individual tracks having spatial overlap with each other by the means of time resolution without incurring an image shift between time steps. This shall be possible for tracks that arrive at the same location, involving the same pixels, separated in time by 0.1 seconds. This requirement includes the case of alpha tracks overlapping with other alpha tracks. This requirement also includes the case of alpha tracks overlapping with beta tracks.

• The alpha-particle energy of each track shall be measurable at an energy resolution no worse than 300 keV for any one particular angle of incidence. The detector is not required to determine the angle of incidence, but the user may be inferring the angle of incidence from the total track length for a known energy of incidence. The energy accuracy for the determination of incident energy shall be no worse than 300 keV between calibrations.

• The minimum detection efficiencies (MDE) for incident radiation of incidence angles of 5° to 90° with respect to the plane of the detector surface shall be:

o 0.1MeV to ≤ 1 MeV alpha-particles: MDE > 0 % o 1 MeV to ≤ 2 MeV alpha-particles: MDE 80 % o 2 MeV to 8 MeV alpha-particles: MDE 90 % o 0.1 MeV to ≤ 0.2 MeV beta-particles: MDE > 0 % o 0.2 MeV to ≤ 0.6 MeV beta-particles: MDE 30 % o 0.6 MeV to 1.5 MeV beta-particles: MDE 25 %

Hardware:

• The system shall be available as a turn-key commercial system.

• The system shall be compatible with bench-top operation in an area not to exceed 300 cm x 750 cm of bench space and not be taller than 450 cm.

• Imaging shall be performed by a pixel-based detector.

• Each pixel shall be supplied with individual energy calibration which shall be applicable to including the

0.1 to 8 MeV range.

• The size of individual pixels shall be no larger than 55 micrometers.

• The detecting surface of the detector shall not be smaller than 2.8 cm x 7 cm.

• If an array of detector is used to achieve the total area required, it must be possible to operate them as if they were spatially seamless so that there is no detection dead area between individual elements.

• The detecting surface upon which radiation impinges shall be a flat, smooth solid.

• The detection and imaging that meets the criteria in this document shall be performed in real time while a user views the live results unless otherwise specified as an off-line/ post-collection process.

• The live operation shall have a possible total counting period (a.k.a. exposure time) of at least 1 week in length, whereas the minimum counting time possible shall be 1 second. (i.e. counts of precisely 1 second shall be possible. Counting durations of over 1 week shall also be possible). The radiation imaging spectrometer system shall provide a means to readily select the counting time before a count starts. Counting times selectable shall include the range of 0.01 seconds to an indefinite counting time to be terminated at the will of the user from a live-counting state.

• The radiation imaging spectrometer shall allow a count to be started and stopped, and shall allow the resulting data to be saved and erased, , and then the radiation imaging spectrometer shall allow a new count to be restarted, all without moving the sample off the spectrometer.

• A microscope or any other equipment larger than 30 cm x 40 cm or shall not be required to view the results. The system shall be portable.

• The detector shall not require the use of special gases or the manipulation of liquids other than a coolant, to meet the above criteria.

• The detecting surface of the detector shall be such that if an electrically insulated microscopic dust grain that is emitting alpha-particles were to land on the surface of the detector, the detector would remain operable. Likewise, it shall be possible for a user to puff air by the user’s own means* across the detector to remove loose dust from the surface. For example, the user may want to use a can of compressed air of the type normally used to clean dust off delicate surfaces. Likewise, it shall be possible for a user to intentionally direct air across the detector surface by the user’s own means* for the purpose of detecting alpha-particles emitted within the air stream. (* An air-current supply is not being required as part of the device.

• There shall be no permanent physical barrier such as a cover-glass, over the surface of the detector since it is imperative that the user be able to pass an air stream or dust particles by the surface and expect to reach full detection capabilities of that air and/or dust while the detector is live. Operation without a cover must be possible for times that can eventually accumulate to months of exposure without degradation of the detector performance as long as the user doesn’t mar or similarly damage the surface by physical forces. The detecting surface of the detector shall be directly viewable by eye, and it shall not be recessed to the degree that it would not be possible for a user to touch the surface with a non-damaging physical object 2.5 cm x 2.5 cm in size.

• The detector shall be reusable. The detection of an individual alpha-track shall not degrade the detector such that it cannot continue to meet the detection criteria above for additional alpha tracks in the same location in the future.

• The radiation imaging spectrometer system shall be water-cooled by a small compressor-based chiller such as a Huber Minichiller, that is integral to the system and operable by PC without requiring a 2nd computer. The chiller shall be no larger than 25 cm x 40 cm and be suitable for a benchtop. The chiller shall be capable of continuous operation for at least 4 weeks and provide a temperature indicator, fill level indicator, and status outputs, and be easy to fill and empty by the customer. The chiller shall be compatible with 110 V 60 Hz and not require any engineering or development by the customer. Any cables, supports, or tubing shall be provided by the Contractor.

• The presence of water-cooling or a chiller device shall not increase the relative humidity (RH) of the surface of the sensor above 65 % RH.

• The presence of a water-cooling or chiller device shall not vibrate the surface of the sensor. The detector assembly and system shall not vibrate or produce its own air currents across the sensor surface that the user can’t reasonably dampen or block without degrading the performance criteria. For example, if the system has a cooling fan, the air movement caused by the fan must be blocked from the surface of the detector sensor (or be capable of being blocked) so that the user can control their own air and dust exposure of the sensor at will without imposing a condition of overheating of the system. Likewise, vibrations could also interfere with the user’s need to control the environment at the surface of the sensor face and shall be minimal. This includes a requirement for there to be quiet operation so that the surface of the sensor does not “trampoline” like a speaker or in resonance, causing material on the surface of the sensor to be displaced.

• Variations in ambient laboratory temperature of up to 2 °C shall not cause the calibration to drift more than 10 %, or the system shall have a means to track the temperature and allow for corrections to be made. The performance in detection efficiency, spatial resolution, energy resolution, spatial accuracy, and energy accuracy, shall be consistent over time and not deviate by more than 10 % per month under normal operation.

• If recalibration requires the use of proprietary software not provided to the user, meaning that a site visit or shipping of the detector back to an authorized service location is required, then the performance shall not deviate by more than 10% per 2 years so as to minimize interruption in the use of the device.

Data Format:

• The radiation imaging spectrometer system shall be able to save the images produced, and the pixel intensities of all pixels comprising the images on a computer in a format that retains the original dynamic range of the image data. This collection of image shall be part of the system and not require the user to produce and use an independent camera.

• The image files shall be in either tiff or raw format, or if not those formats, then a lossless format that can be read by generic image processing software such as ImageJ or MatLab.

• The software used to meet the criteria above shall be compatible with Windows 10 Enterprise operating system.

Installation:

The NIST Technical Point of Contact (TPOC) shall be responsible for installation of the equipment and software. Installation will occur by the NIST Technical Point of Contact (TPOC) within 3 weeks of shipment reception by the TPOC.

At minimum, the Contractor shall provide an email or phone support for installation of hardware and software on preexisting Windows 10 computer. Replies to emails or phone calls shall not exceed 3 days.

Warranty:

The Contractor shall provide, at a minimum, a one-year warranty for the equipment. The warranty shall cover all parts, labor and travel. The warranty shall commence upon successful completion of delivery, installation, training.

Training:

The Contractor shall provide training via system documentation, email, or phone for the NIST Technical Point of Contact (TPOC). Training shall cover normal operation, troubleshooting, and routine maintenance. Training shall occur within 10 days of installation.

III. DELIVERABLES

Description

Quant ity Due Date

WidePIX 2x10 radiation imaging spectrometer One 90days after award of requirement.

Water cooler chiller One 90 days after award of requirement

Training of NIST TPOC One 10 days after installation.

IV. ACCEPTANCE CRITERIA

After installation by the NIST Technical Point of Contact (TPOC), the TPOC shall coordinate with the

Contractor to test and demonstrate that all minimum required specifications have been met. The demonstration of specifications may occur during training. Final acceptance by the Government will be given after successful delivery, installation, training and demonstration of instrumentation specifications.

V. GENERAL INFORMATION

Security: NIST is a restricted campus. An identification badge is required for access for entry into buildings and also is shown to the Security when entering the campus.