Earth and Planetary Science
EPS Planetary Science

Berkeley Scientist Uses a Next-Generation, High-flux D-D Neutron Generator

Monday, February 13, 2017

Paul Renne is co-author of “Beam-induced Back-streaming Electron Suppression Analysis for Accelerator Type Neutron Generators.” The article was released on 2 January 2017 in the journal Accelerator Physics.

A facility based on a next-generation, high-flux D-D neutron generator has been commissioned and it is now operational at the University of California, Berkeley. The current generator design produces near monoenergetic 2.45 MeV neutrons at outputs of 10^8 n/s. Calculations provided show that future conditioning at higher currents and voltages will allow for a production rate over 10^10 n/s. A significant problem encountered was beam-induced electron backstreaming, that needed to be resolved to achieve meaningful beam currents. Two methods of suppressing secondary electrons resulting from the deuterium beam striking the target were tested: the application of static electric and magnetic fields. Computational simulations of both techniques were done using a finite element analysis in COMSOL Multiphysics. Experimental tests verified these simulation results. The most reliable suppression was achieved via the implementation of an electrostatic shroud with a voltage offset of -800 V relative to the target.

Paul Renne is professor in residence at the Berkeley Earth & Planetary Science Department and director of the Berkeley Geochronology Center. He is broadly interested in application of geochronology and paleomagnetism to various problems in the evolution of the lithosphere, hydrosphere, atmosphere and biosphere.

For the full-length article please click here.