Papers

Feasibility of Reactor Pulse Operation at the IJS TRIGA Reactor for Nuclear Instrumentation Detector Testing at Very High Neutron Flux Levels

Abstract: A vital phase in the development of nuclear instrumentation detectors and associated electronic data acquisition systems is experimental testing and qualification in a well-characterized and representative radiation field in a reference irradiation facility. The neutron flux levels in modern material testing reactors (MTRs) are in the range of 1014 – 1015 n cm-1 s-1. However, the number of dedicated test facilities in Europe is currently decreasing, with numerous research reactors recently and soon to be shut down. The 250 kW JSI TRIGA reactor is a very well characterized reactor in terms of the knowledge of the neutron and gamma fields, a product of the work performed at the JSI over the last decade, mostly in collaboration with the Instrumentation, Sensors and Dosimetry Laboratory at CEA, Cadarache. Therefore it fulfills very well the first criterion for a reference facility. However, in steady state operation, it is able to generate a maximum neutron flux level of around 2×1013 n cm-1 s-1, i.e. several orders of magnitude lower than the MTR-relevant range. In steady-state mode, the requirement of representativeness is therefore not fulfilled well. On the other hand, the JSI TRIGA reactor can operate in pulse mode, due to its prompt negative temperature coefficient of reactivity. Depending on the inserted reactivity, the peak power can reach up to 1 GW, and the pulse duration is of the order of a few seconds (low and long pulses), to 5-10 milliseconds (high and short pulses). The neutron flux level is proportional to the reactor power level, therefore the highest attainable flux is nearly 1017 n cm-1 s-1, albeit for a short amount of time. In 2019, a bilateral collaboration project between the CEA and JSI was initiated, to investigate the possibility of neutron flux measurements performed at very high neutron flux levels in reactor pulse operation, made possible by a modern, validated, wide dynamic range neutron acquisition system. The project aims at demonstrating the feasibility of nuclear instrumentation and associated electronic data acquisition system tests at the JSI TRIGA reactor at neutron flux levels relevant to MTRs. This paper presents the first measurements in reactor pulse operation, performed during an experimental testing campaign in collaboration with researchers from the CEA, as well as with colleagues from Instrumentation Technologies using a Keithley electrometer-based acquisition system and an I-Tech-developed current meter. A more exhaustive experimental campaign is scheduled to be carried out at the JSI TRIGA reactor jointly by CEA and JSI researchers in the autumn of 2020.

Filling pattern measurement using a 500 MHz digitizer at Soleil and APS storage rings

Libera Medical Brochure

Libera Book 2020

Fast Orbit Stabilization for Proton and Heavy Ion Synchrotrons & Digital LLRF System for Medical Accelerators

Design consulting for Xylon

BPM Processor Upgrades At SPEAR3

In this paper we show measurements and discuss our experience with the Libera SPARK series of BPM processors and comment on the software integration.

Beam Measurements Results Of A BPM System Implementing The Pilot-tone Stabilization Concept

The next generation light sources will require Beam Position Monitoring systems capable of performing high resolution measurements as well as assuring long-term measurement stability. One possible solution to stabilize the position measurements long-term drifts is using a pilot-tone signal which is transferred together with the BPM signal and measured by the BPM electronics.