May 26, 1999
|All major components and materials for the vacuum vessel have arrived at VTA-DynaVac. On Friday, May 21, 1999, Darren Garnier and Isaac Benowitz (a Columbia summer student) visited to do a visual inspection of the materials.|
|First look at the vacuum-vessel-to-be. Darren (left) and Isaac (right) give the components scale. The vessel is comprised of 6 large pieces, each approximately 16x9x3' in size. There are two half cylinders and two tori-spherical heads that are split in half for shipping. The completed vessel will be 16 1/2' in diameter and 10' tall. See last month's update for a isometric drawing of the vessel.|
|Here are a couple of views of the inner surface of the heads. It is covered with a plastic film to protect it from scratches and dirt during shipment and assembly. There is also a carbon steel structure that supports the heads from warping while they are split (to be removed after reassembly in the LDX cell). The inner surface has a very good quality #4 finish for good vacuum performance.|
|Various other parts and components of the LDX vacuum vessel ready for the assembly: the 6 stand legs (upper left), ConFlat flanges and copper seals (above) and nipples for diagnostic ports (left).|
|The professionals: Rick Gainey and Jose Alameda of DynaVac will be part of the team that will come to the LDX cell to assemble the vessel beginning in early June. (left)
Certification tag of head by metal former Enerfab Inc. (below)
Floating Coil Conductor
|The LDX strand has been cabled without incident at LBNL and is back at the conductor manufacturer, IGC. The cable is in a single piece, 1600m long. This is slightly longer than the minimum length expected from the shortest piece of wire. LBNL did a very efficient cabling job by welding a copper lead wire to the shortest piece length to yield the longest overall cable possible.
IGC will begin to respool this cable on a reaction spool this week, allowing the conductor to be sent to BNL on June 1, 1999 for heat treatment. Reaction heat treatment should last about 30 days.
|The final manufacturing design review for the floating coil helium vessel was held on May 4. Mike Morgan (Ability Engineering) presented the manufacturing plan for the helium pressure vessel, coil form, and winding mandrel.
The first item on the schedule to be completed is the manufacture of the coil form and winding mandrel which will be used by Everson in July. Presently, Ability has completed about 80% of the aluminum mandrel and all of stainless steel parts for the coil form.
The aluminum winding mandrel which is nearly complete (right). Parts of the stainless steel coil form (below).
|The cell is currently being cleared out in preparation for arrival of the vacuum vessel in June (right). Large rough vacuum pumps are being installed and tested in preparation for leak testing of the vacuum vessel in July (below).|
Simplified Launcher/Catcher Design Activity
|Bob Ellis at PPPL has been working on the design of the simplified Launcher/Catcher. Several concepts, including a rack and pinion lift arrangement, a leadscrew and bearing, an inside-vessel cable lift, and an external cable lift operating through a (long) bellows-type linear motion feedthrough have been examined, with the latter concept emerging as the favorite. Preliminary force, stress and bellows stroke calculations have been initiated. A brainstorming meeting at MIT on 4/27/99 provided valuable inputs to the design concept.|
|The charging coil design was revised to accommodate the final floating coil specifications and the reduction of the outside radius of the cryostat by 1.5 cm. A 10 % safety margin was added to allow for losses. The present charging coil design has 40 layers, and this design meets stress, field, and current density limits provided by Oxford. Relative to previous charging coil designs, stored energy has been reduced to 11.2 MJ and the peak field to 5.64 T. Oxford has been informed of the changes, and a new potential vendor, Magnex, has been identified. After initial contacts, a description of the charging coil has been sent to them, and they are considering the project.
Drawing by R.J. Camile, Jr.