Development of Nuclear Event Detection and Circumvention Controller Technology

SBIR N04-152

In this Phase II program, AET developed a nuclear event detector and circumvention controller (NEDCC) system that was initially intended to be used onboard the US Navy Fleet Ballistic Missile upgrade program. To optimize the performance and reliability of the NEDCC, two options were pursued during the Phase II program. The lowest risk option includes a silicon chip with CMOS analog and digital circuitry along with a separate P-I-N detector diode. In addition, AET developed the technology for a monolithic silicon chip containing the P-I-N diode. A US patent has been awarded to AET for this monolithic NEDCC. The Honeywell Solid State Electronics Center has been selected as the industrial partner of AET for wafer fabrication and related services.

The NEDCC has been commercialized in conjunction with Aeroflex of Colorado Springs. The Aeroflex NEDCC radiation-hardened, monolithic Nuclear Event Detector (NED) processes signals received from one or more photodiode sensor(s), and provides digital outputs that indicated whether an ionizing dose rate has been exceeded. The dose rate threshold(s) are user settable between 1×105 rad(Si)/s to 1×107 rad(Si)/s using an external resistor.

The NEDCC operates from a single 5V (+/- 10%) supply voltage. The active low digital output signal (NED_HS_Z) is normally high (logic 1), and transitions to a logic 0 state (output less than or equal to VOL) within 10 nanoseconds after an event has been detected (photodiode signal @ 50% of its maximum value). After an event, the digital output returns to its logic 1 state after a time that is user settable by an external capacitor and resistor network (EXTRC). The delay of this time can be adjusted between 20?s to 1 ms. The UTNEDCC also incorporates a power-onreset circuit which ensures that the device powers up with its outputs initially in a LOW state, followed by a switch to a HIGH state after the programmed delay time.