1. Vacuum System for IFE Chambers
C. Priniski, C. Gentile, W. Blanchard, L. Ciebiera, F. Dahlgren,
G. Gettelfinger, C. Jun, S. Langish; Princeton University PPPL
J. Sethian; Naval Research Laboratory
HAPL Meeting, November 8th-9th, 2005 Rochester, NY
5m R Chamber with 40 Beam Configuration
Operational Pressure Curves
Abstract/Requirements
In support of The High Average Power Laser (HAPL) Program, the Princeton Plasma Physics Laboratory has designed a vacuum pumping system (VPS) for an Inertial Fusion Energy (IFE) target chamber. The VPS is designed to maintain a base operating pressure of < ~ 1 m torr during a cyclic gas load (for full operation at 5 Hz) of 141 torr-liters / sec. Previous work has focused on a target chamber is fitted with a mid-plane toroidial duct (for magnetic intervention option), which incorporated 60 pumping vents, with 2 TMPs per vent 120 TMP's total. Recent design work focuses on pumping through traditional ducts with the same TMPs attached to plenum spaces on the ends. 30 TMPs would be clustered in each plenum chamber. Each TMP is capable of pumping approximately 6,000 l/sec providing sufficient capacity to support continuous 5 Hz operations. System in leakage is assumed to be 1 x torr which is consistent with vacuum chambers of similar size and complexity.
The pumping duct/plenums are of a modular design that allows for easy scaling for use in various volume and target yield IFE designs. As in the previous design, the vacuum pumping system employs, to the largest extent possible, commercial off the shelf components (COTS) with a proven record of high operational availability in similar (MFE) applications. The system has been designed to transition from D-D to D-T operation with minimal configuration change. A full scale system has been estimated to cost < $ 20M .
6.5 m Toroidal Duct
11 m Laser Ducts
11 m Plenum Ducts
2m Diameter
5 m Plenum Ducts
5m Length
Heat Load to the TMP’s
Sample configuration for 5m chamber case, two symmetric duct assemblies are used in this size. All TMPs are line of site shielded from radiated energy in this configuration.
Vacuum System Sketch
Configurations Explored
6.5m
Toriodal Duct
11m
Laser
Ports 7m 5m
Plenum
Ducts
1.29*106 liters
5.72*106 liters
1.58*106 liters
6.11*105
liters
Pult =
0.21 mtorr
1.7 mtorr
1.6 mtorr
0.35 mtorr
Even for high assumed delta T values the heat load to the TMPs from molecular flow is suitably low.
Vacuum System Est. Component Cost