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Title: Neutron source design for the Los Alamos APT system

Conference · · Transactions of the American Nuclear Society; (United States)
OSTI ID:6840471
 [1]
  1. Los Alamos National Lab., NM (United States)

The Los Alamos National Laboratory accelerator production of tritium (APT) design incorporates a high-energy (1-GeV), high-current (200-mA) proton accelerator, a tungsten neutron source, and a moderating blanket that contains [sup 3]He for the production of tritium. To reduce the power density in the neutron source to acceptable levels, the incident proton beam is expanded to a 0.5- x 1.0-m [open quotes]beam spot.[close quotes] The beam passes through a double-wall vacuum interface window that is constructed of Inconel and is cooled with D[sub 2]O. The protons then enter a 1.3-m-diam x 3.5-m-long vessel also made of Inconel that contains [sup 3]He at moderate pressure (0.66 MPa) and 104 tungsten rod bundles that are distributed along the length of the vessel. The protons impinge on the tungsten and produce high-energy neutrons through the process of spallation. Behind the Inconel vessel is a proton backstop made of zirconium and lead that provides an additional source of neutrons and fully stops the proton beam. The Inconel vessel is surrounded by an annulus of aluminum-clad lead that is cooled with D[sub 2]O. Neutron multiplication occurs in the lead through additional spallation and (n,xn) reactions. Surrounding the lead is a thin annulus of [sup 3]He contained in aluminum tubing, a D[sub 2]O moderator, another annulus of [sup 3]He, and a D[sub 2]O reflector. Neutrons are moderated to near thermal energies in the D[sub 2]O. Tritium is produced through neutron capture in [sup 3]He that is circulated and processed continually. Thermal neutrons that are scattered back into the neutron source are preferentially captured in the [sup 3]He, thereby reducing the parasitic capture in the tungsten. The entire assembly of the neutron source vessel and surrounding blanket of lead, [sup 3]He, and D[sub 2]O are contained in a steel vessel.

OSTI ID:
6840471
Report Number(s):
CONF-931160-; CODEN: TANSAO
Journal Information:
Transactions of the American Nuclear Society; (United States), Vol. 69; Conference: American Nuclear Society (ANS) winter meeting, San Francisco, CA (United States), 14-18 Nov 1993; ISSN 0003-018X
Country of Publication:
United States
Language:
English