International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna

Signal and Noise Analysis in TRION Detector

D. Vartsky¹, G. Feldman¹, I. Mor¹, M. B. Goldberg¹, D. Bar¹, I. Mardor¹, and V. Dangendorf²

¹Electro-Optics Division, Soreq Nuclear Research Cente Yavne, Israel
²Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany

Corresponding Author: david@soreq.gov.il

TRION is a sub-mm spatial resolution fast neutron imaging detector, which employs an integrative optical time-of-flight technique. The detector was developed for fast neutron resonance radiography (FNRR), a method capable of detecting a broad range of conventional and improvised explosives. A more detailed description of the system can be found in another contribution to this conference by our group. (see Mor et al).

In this paper we have analyzed in detail, using Monte-Carlo calculations and experimentally determined parameters, all the processes that influence the signal and noise in the TRION detector. In contrast to event-counting detectors where the signal-to-noise ratio is dependent only on the number of detected events (quantum noise), in an energy-integrating detector additional factors, such as the fluctuations in imparted energy, number of photoelectrons, system gain and other factors will contribute to the noise. It is shown that, even under ideal light collection conditions, a fast neutron detection system operating in an integrative mode cannot be quantum-noise-limited due to the relatively large variance in the imparted proton energy and the resulting scintillation light distributions.