Fabrication of a 3X3 Neutron Pinhole Array

Abstract

Neutron imaging diagnostics are needed for understanding the principles of fusion ignition. Current experiments on the University of Rochester OMEGA laser facility and future experiments at the NIF require a new level of complexity in neutron diagnostics that has not yet been achieved. Previous shots have fielded a one dimensional pinhole array to gather an image of a sphere’s neutron emission during the implosion. This one dimensional pinhole array that consisted of two pinholes on a plane was a challenging manufacturing task and was a substantial accomplishment for its time. Future neutron imaging diagnostics will require a two dimensional pinhole array to gather a more comprehensive set of data. This two dimensional pinhole array, consisting of 3 pinholes one three planes to form a 3x3 array of pinholes, added a new level of complexity to the manufacturability. A method for fabricating this pinhole array was developed and the finished instrument was fielded in July and October 2006. This paper describes the fabrication process to producing this pinhole array and shows some of the early data taken with it at the Omega facility.