Gamma-rays (log scale)
Gamma-ray energy (linear scale)
Naval operations and implementation by Coast Guard personnel.
NRL Implementation: NRL added custom soft- ware that works in concert with the Canberra software to take the scientist out of the decision-making loop in the field. This algorithm takes into account the com- plexities of past data collected at sea by NRL, as well as the spectral characteristics of nuclear weapons mate- rials and the implications of emerging threats such as clandestine radiation dispersal devices (RDD). Techni- cal issues addressed include the nature of the target to be located and identified, the treatment of natural and anthropogenic backgrounds, shielding considerations, measurement ranges, and dwell times. The final output of the software is a simplified report of what threats, if any, were found. In its final form, HELGA II will be completely autonomous in performing the functions necessary to identify nuclear weapons materials and alert the appropriate personnel.
Possibilities: The HELGA II prototype will demonstrate deployment on a small boat, while paving the way for a large range of alternate deployment options: small and large boats, remotely controlled jet ski platforms, helicopters, and man-portable systems. Such flexible deployment scenarios allow a large range of surveillance options: small HELGA II craft such as boats and jet skis allow a wide zone of control around fleet assets; HELGA II craft of any size allow for covert surveillance of boats and ships; HELGA II buoys at choke points allow continuous surveillance of passing watercraft; man-portable systems allow detailed search and identification in ship boarding scenarios.
[Sponsored by ONR]
2005 NRL Review
FIGURE 7 Nal and Ge comparative measurement of same multisource target.
1 References http://www.anl.gov/Science_and_Technology/History/ Anniversary_Frontiers/aetofdr.html, accessed 18 November 2004. 2 L.A. Beach and G.W. Phillips, “Development of a Rugged HPGe Detector,” Nuc. Instr. Meth. Phys. Res. A242 520-524 (1986). 3 http://www.history.navy.mil/faqs/faq90-5c.htm, accessed 18 November 2004.