The mirror fusion test facility (MFTF) vacuum vessel will be about 60 m long and 10 m in diameter at the widest point. The allowable operating densities range from 2×109 to 5×1010 particles per cm3. The maximum leak rate of 10−6 Torrπl/s is dominated during operation by the deliberately injected cold gas of 250 Torrπl/s. This gas is pumped by over 1000 m2 of cryopanels, external sorbtion pumps, and getters. The design and requirements have changed radically over the past several years, and they are still not in final form. The vacuum system design has also changed, but more slowly and less radically. This paper discusses the engineering effort necessary to meet these stringent and changing requirements. Much of the analysis of the internal systems has been carried out using a three-dimensional Monte Carlo computer code, which can estimate time-dependent operational pressures. This code and its use will also be described.

Final design of the neutral beam lines for TFTR has been completed. A prototype has been assembled at Lawrence Berkeley Laboratory and is undergoing testing as part of the Neutral Beam System Test Facility (NBSTF). The final neutral beam line (NBL) configuration differs in several details from that previously reported upon; certain components have been added; and testing of the cryopump system has led to some design simplification. It is these developments which are reported herein.

The Tokamak Fusion Test Reactor will be installed at the Princeton Plasma Physics Laboratory facility. This is a major step to reach the goal of fusion power using toroidal magnetic fields for plasma confinement. A major part of this test reactor will be four neutral beam injection systems. These systems will inject 20 MW of 120 kV neutral deuterium atoms into the plasma for 0.5 seconds. In order to achieve the required power input to the plasma, several systems are required within the neutral beam line. These are the source, neutralizer, ion deflection magnet, calorimeter and retraction system, ion dump, cryopumps and vacuum enclosure. All of these systems have constraints imposed which increase the complexity of their designs. Since all systems must operate in a tritium environment, remote handling capabilities must be incorporated into the design. An overview is presented of the Lawrence Livermore Laboratory/Lawrence Berkeley Laboratory Neutral Beam Injection System design. Specifications for the machine and a general description of the total system are presented.

I I UC- 35 Presented at the American Nuclear Society Annual Meeting, New York, NY, June 12-17, 1977 LBL-5943 c;,/ RECE~VED tf~ vV~~~·\:CE BERK~ (:-{ ~NY)k,n, TORY OCT 1. 7 1977 LlBR!\RY J.\ND DOCUMENTS SECTION For Reference Not to be taken from this room Cryopump, Neutral-Beam