A comparison of the losses induced in step-index multimode, graded-index multimode, and single-mode fibers by pulsed radiation exposure has been made among 12 laboratories over a period of five years. The recoveries of the incremental attenuations from to 10' s are reported. Although a standard set of measurement parameters was attempted, differences between the laboratories are evident; possible origins for these are discussed.

A comparison of the losses induced in step index multimode, graded index multimode and single mode fibers by pulsed radiation exposure has been made among 12 laboratories over a period of 5 years. The recoveries of the incremental attenuations from 10 to 10 s are reported. Although a standard set of measurement parameters was attempted, differences between the laboratories are evident; possible origins for these are discussed.

Differentially filtered, photoconductive, neutron-irradiated diamond detectors have been employed to investigate the temporal and energy distribution of an intense pulsed proton beam. Results were compared against measurements obtained using differentially filtered radiachromic film, electromagnetic (EM) techniques, timeof-flight techniques, and calorimetric instruments.

Sic transistors can operate at very high temperatures and survive very high radiation doses. These characteristics make Sic potentially the ideal technology for nuclear power applications. In this paper we report, for the first time, on the active in-core irradiation of 6H-Sic depletion-mode junction field-effect transistors (JFETs) at 25" and 300°C in a nuclear reactor operated at 200 kW. No significant degradation in the device characteristics was observed until the total neutron fluence exceeded 1015 n/cm2 for irradiation at 25OC, and no significant changes were observed even at 5 x 1015 n/cm2 at 300°C. The results of this experiment may also indicate exciting evidence for the anneal of neutron displacement damage for dcvices irradiated at 300°C.

Modal noise, which can cause severe distortion in signals transmitted by fiber optics, is an interference effect that is made more severe by the narrow spectral width of single-mode lasers. The linearity of these devices may be totally obscured after the optical signal has passed through the connectors and fiber lengths of a practical signal system. Dithering the laser's operating point by means of a high-frequency current (>2 GHz) has been found greatly to reduce modal noise.