Speaker
Description
Abstract:
With the advancement of science and technology, the field of Inertial Confinement Fusion (ICF) has entered a new era where fusion yields are sufficiently high to enable nuclear measurements to provide multidimensional information encompassing spatial, temporal, and spectral dimensions. Nevertheless, neutron yield remains one of the most critical parameters of concern in the diagnostics of ICF facilities. Currently, neutron yields must be measured across several orders of magnitude, with the upper limit reaching approximately 2×1016 neutrons per shot.
To address high-intensity ICF neutron yield measurement, a neutron detector based on fission reactions has been developed. Drawing inspiration from the design of Vacuum Compton Diode detectors, this detector comprises a vacuum chamber, front window, collector, anode, and rear window. Its operational principle is as follows: Fusion neutrons pass through the detector's front window and impinge on the collector, which consists of a fission foil with a beryllium substrate (primarily composed of natural uranium). Neutrons interact with uranium to produce fission fragments. As these fragments escape, they ionize the collector material, generating secondary electrons. On average, each fragment produces approximately 300 secondary electrons. The anode, constructed as a stainless-steel grid, is positively biased. The secondary electrons are accelerated by the anode voltage and ejected from the collector, generating a positive signal and recorded by a digital oscilloscope.
This detector exhibits fast temporal response, compact structure, and user-friendly operation, making it suitable for measuring ICF fusion neutron yields. Its measurable range spans from 1×1014 to 1×1018 neutrons per shot.
Key words:
Inertial Confinement Fusion, Fusion Neutron, Neutron Yield, Fission Fragment, Secondary Electron
