July 08 Issue - Employee Monthly Magazine

GEANIE: Fulfilling wishes

Photo by LeRoy N. Sanchez

Ron Nelson of Neutron and Nuclear Science at the Los Alamos Neutron Science Center (LANSCE) stands near the center of the Germanium Array for Neutron-Induced Excitations (GEANIE). The GEANIE instrument consists of 26 germanium crystals, an automated liquid nitrogen filling system, and an array of electronics. Its state-of-the-art electronics and detectors are used to address issues of nuclear structure, spectroscopy, and cross-section measurements for both stockpile stewardship and basic science. The GEANIE detector views gamma rays from an encapsulated plutonium-239 sample as it is bombarded with neutrons from the weapons neutron research source.

LANSCE has two spallation neutron sources: the Manuel Lujan Jr. Neutron Scattering Center and the Weapons Neutron Research facility in which GEANIE resides. Together they provide neutrons over an unprecedented range of energies—extending from sub-millielectronvolts to hundreds of megaelectronvolts—that are used for both neutron scattering and nuclear physics research.