PINS3-CF Chemicals and Explosives Identification System 2

ORTEC PINS3-CF is a portable isotope neutron spectroscopy (PINS) non-destructive evaluation system that analyzes and provides on-site identification information on the composition of unidentified or suspicious chemicals inside unopened thick steel containers. Designed to identify chemicals within a container without the need to disassemble, touch, physically sample or open the container, the system is widely deployed as part of national equipment and provides a secure method of identifying "suspicious" packaging contents.

PINS3-CF is easy to use with the ORTEC trans-SPEC-N mechanically cooled high-purity germanium spectrometer. trans-SPEC-N has been specifically designed and tested to replace liquid nitrogen-cooled detectors currently used in neutron chemical analysis systems and provide the necessary in-situ spectral data for non-invasive chemical identification.

PINS3-CF provides significant advantages over previous liquid nitrogen systems by eliminating the logistical and safety issues associated with liquid nitrogen storage and transportation, equipment handling, maintenance and training.

PINS application

• - Artillery, Rockets, Mines.
• Containers - cylinders, tanks, bags, briefcases, parcels.
• Chemicals - chemical warheads, gases, fumes.

PINS overview
The Portable Isotope Spectroscopy (PINS) Chemical Identification System non-destructively identifies hazardous compounds and mixtures. There is no need to open or touch the test object, greatly increasing safety. As shown in the figure, PINS tests objects with neutrons, which excite the interior of atomic nuclei, causing the excited nuclei to produce gamma rays. Each chemical element's gamma rays have a specific energy intensity pattern, or spectrum, so by analyzing the gamma ray spectrum, PINS software can identify chemical elements within a test object and determine whether the object contains chemical warfare agents, fillers (such as sand), or smoke-producing chemicals.

Working principle
PINS3-CF uses neutrons produced by the fission of the radioactive isotope californium-252 (Cf-252). The standard PINS3-CF 5 microgram Cf-252 source produces 10 million neutrons per second. The source emits neutrons in all directions, with approximately 1,000 neutrons striking each square centimeter of the test object's surface per second. Because neutrons are a penetrating form of radiation, most neutrons will pass through the test object's outer shell and interact with the chemicals inside.

Neutrons from a source excite the nuclei they encounter through inelastic scattering or neutron capture. In either case, excited nuclei decay to their ground state by emitting gamma rays, which are characteristic of emitting nuclei. That is, gamma ray energy and intensity often vary greatly from one type of nucleus to another. For example, hydrogen nuclei emit 2.2-MeV gamma rays when bombarded by neutrons, while phosphorus nuclei emit 1.3-MeV gamma rays.

Neutron-induced gamma rays are measured by a high-purity germanium (HPGe) spectrometer and classified into spectra by the spectrometer electronics. By analyzing the spectrum, the chemical elements excited by the neutrons can be determined and the chemicals within the test object can be identified.

Run PINS
Developed specifically for field deployment, PINS3-CF is portable and rugged. Its components include a mechanically cooled spectrometer with an integrated multi-channel analyzer, a small radioactive californium neutron source, a detector stand and shield, and a laptop computer to provide the user interface. Custom software displays data in real time as it is collected and provides comprehensive monitoring and analysis options.

Laptop used as PINS3-CF control panel. The computer allows the user to initialize the instrument, start and stop data acquisition by the gamma-ray spectrometer, display and analyze the resulting gamma-ray spectrum. The connecting cable, 82 feet (25 meters) long, keeps the computer at a safe distance from the radiation isolation zone and provides communication between the computer and the gamma-ray spectrometer.

trans-SPEC-N mechanically cooled high-purity germanium spectrometer
Unlike the liquid nitrogen-cooled HPGe spectrometer used in previous PINS systems, PINS3-CF uses trans-SPEC-N to mechanically cool the HPGe spectrometer, which does not require liquid nitrogen. The electrical energy required to cool the spectrometer detector is approximately 30 watts. The trans-SPEC-N lithium-ion battery keeps the detector cool for 10 to 12 hours, and the external battery supports "hot swapping" for extended use of the instrument in the field. trans-SPEC-N provides a flexible, modular solution to support on-site detection of chemicals and explosive threats with the following features:

• LN2-Free - Miniature, high-reliability, "runable" Stirling cycle refrigerator requires no liquid nitrogen; detector element is encapsulated in a high-reliability, low-loss, all-metal sealed cryostat.
• High sensitivity - large (>50% relative efficiency) HPGe detector.
• High Stability - Digital electronics provide solutions for difficult analyzes under harsh conditions.
• Bright and clear - VGA resolution display and touch-sensitive operation screen.
• All-in-one integrated design - rugged and compact, no interconnections required - easy to install and use.
• Smart - nuclide identification and activity calculation for nine regions of interest (ROI).
• Reliable connectivity - USB 2.0 and wireless.
• 802.11 communications, built-in GPS and secure digital input/output (SDIO) storage of collected spectra.
• Flexible - Works with a variety of power sources, including internal battery, auxiliary external battery, car battery (any 12 V DC), and line power; switches automatically.

Automated analysis of chemicals
The PINS data acquisition program records and displays spectral measurements from trans-SPEC-N. It also analyzes spectra recorded every 10 seconds, fits peaks of interest, recalibrates the energy scale and performs chemical analysis. The new chemical analysis method is based on the decision tree logic shown and identifies chemicals within the object being measured. The new probabilistic method traces each path in the decision tree and assigns a score to each chemical it may contain. Chemicals with a score are selected as included chemicals.

New chemical analysis methods are faster, more accurate, and more easily expand the list of chemicals that PINS can automatically identify. Currently, PINS automatic analysis software can identify the following chemicals.