By John McHale

SAN DIEGO ? Engineers at Space Electronics, Inc. (SEI), a subsidiary of Maxwell Technologies, recently added a Nuclear Event Detector (NED) to enhance their radiation products.

The device is currently used on the Eurofighter and the U.S. Air Force B-2 Bomber, says Larry Longden, product manager at SEI.

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NEDs are radiation hardened devices that rapidly detect the onset of ionizing radiation in space and military applications, and provide a signal to initiate protection of critical electronics against ionizing-dose-rate-induced upset and burnout. As a result, NEDs protect an electronic system's memory, stop data processing, and drive power supply crowbars and signal clamps, SEI officials claim.

Although the NED product line was originally available in small quantities through another Maxwell Technologies subsidiary, they are now available in large quantities from SEI.

"It detects very fast pulse ionizing radiation from a nuclear weapon?such as gamma rays and x-rays," Longden says.

For example, Longden continues, if a missile or aircraft flies in an area contaminated by a nuclear weapon, the NED will detect ionizing radiation, then shut down the critical electronics, wait a few milliseconds then signal the system to reboot, Longden explains. It also bypasses the built-in test functions when it reboots during a nuclear event, reducing the start-up time to mere milliseconds, he adds.

The SEI NED takes into account all important voltage and temperature variants and comes with a guaranteed radiation-hardness for each level of nuclear event, says Lee Hoffman, an engineering fellow at Honeywell's Aerospace Electronic Systems in Clearwater, Fla, where the NED is used in various aerospace applications. Before the NED Honeywell engineers would have to design similar devices from discrete parts themselves, which could be time-consuming and expensive, he adds.

Hoffman declined to comment on specific applications.

SEI's first NED available is the HSN 3000, which the company builds to requirements of MIL-PRF-38534. A compliant Class H device, it senses nuclear ionizing radiation pulses.

Once it detects a nuclear event, the NED rapidly switches its outputs from their normal high state to a low state with a propagation delay time of less than 20 nanoseconds, SEI officials claim.

A low signal initiates circumvention functions to prevent the upset and burnout of electronic components. The output also initiates hardware and software recovery, and a Nuclear Event Flag signal remembers the event occurred and distinguishes between an actual event and power-up.

For more information on the HSN 3000 NED contact Space Electronics by phone at 858-452-4167, by mail at Space Electronics, Inc., 4301 Sorrento Valley Blvd., San Diego, Calif. 94121, or on the World Wide Web at http://www.spacelectronics.com.