LLNL Tandem Mirror Experiment (TMX) upgrade vacuum system

Conference · Tue Sep 15 04:00:00 EDT 1981

OSTI ID:5983153

Pickles, W L; Chargin, A K; Drake, R P

TMX Upgrade is a large, tandem, magnetic-mirror fusion experiment with stringent requirements on base pressure (10/sup -8/ torr), low H reflux from the first walls, and peak gas pressure (5 x 10/sup -7/ torr) due to neutral beam gas during plasma operation. The 225 m/sup 3/ vacuum vessel is initially evacuated by turbopumps. Cryopumps provide a continuous sink for gases other than helium, deuterium, and hydrogen. The neutral beam system introduces up to 480 l/s of H or D. The hydrogen isotopes are pumped at very high speed by titanium sublimed onto two cylindrical radially separated stainless steel quilted liners with a total surface area of 540 m/sup 2/. These surfaces (when cooled to about 80/sup 0/K) provide a pumping speed of 6 x 10/sup 7/ l/s for hydrogen. The titanium getter system is programmable and is used for heating as well as gettering. The inner plasma liner can be operated at elevated temperatures to enhance migration of gases away from the surfaces close to the plasma. Glow discharge cleaning is part of the pumpdown procedure. The design features are discussed in conjunction with the operating procedures developed to manage the dynamic vacuum conditions.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5983153
• Report Number(s): UCRL-86270; CONF-811113-6; ON: DE81030314
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700200* -- Fusion Energy-- Fusion Power Plant Technology
BEAM INJECTION
CRYOPUMPS
DESIGN
EQUIPMENT
GETTERS
LABORATORY EQUIPMENT
LINERS
MAGNETIC MIRRORS
NEUTRAL ATOM BEAM INJECTION
OPEN PLASMA DEVICES
PUMPS
SPECIFICATIONS
THERMONUCLEAR DEVICES
TMX DEVICES
VACUUM PUMPS
VACUUM SYSTEMS