From: Tim Stevenson [tstevens@pppl.gov]
Sent: Friday, September 06, 2002 2:36 PM
To: Wayne Reiersen
Cc: hkugel@pppl.gov; hneilson@pppl.gov
Subject: Re: Review of GRD
Wayne,

In the GRD NBI section quoted below, the pulse length of 1.2 seconds is mentioned as an upgrade. First, the existing NBI system will pulse to 0.5 seconds, with more reliable results at 0.3 seconds. No mention of this pulse length is included, but it is a very fixed limit of this system.

Second, the upgrade to 1.2 seconds is a very big leap in time, technology, and cost that includes upgrades to other auxiliary subsystems also, like the water system. The facility should not be initially designed to accommodate the 1.2 second system as stated because the costs will be prohibitive for the initial beam phase and the upgrade to 4 beam phase. Rather, the existing system should be installed so as not to prevent a future upgrade to 1.2 seconds. This 1.2 second upgrade will require extensive changes.

Henry and I had this conversation earlier today so I write with his concurrence.

Regards,

Tim


3.2.1.4.6.1 Neutral Beam Heating
3.2.1.4.6.1.1 Initial NB Heating Complement
Two of the four beamlines previously used on the PBX-M project will be installed as part of the NCSX Fabrication Project. One will be configured in the co-direction (the nominal direction of the plasma current) and one in the counter-direction. The tangency radius shall be inside the magnetic axis for the nominal 1.7T high beta equilibrium and located such that the beam does not intercept the inboard first wall.
3.2.1.4.6.1.2 Ultimate NB Heating Complement
a) The facility shall be designed to accommodate neutral beam heating using the four (4) beamlines previously used on PBX-M (as a future upgrade) in two possible configurations: [1] 2 co- and 2 counter-directed beamlines and [2] 3 co- and 1 counter-directed beamlines.
b) The facility shall be designed to accommodate an extended heating pulse duration of 1.2s.