Discussion of our possibilities with UMN shop (Jon Kilgore)

We'd like to discuss some details of the design. Later, we will also want labor-cost estimate for certain parts that will be produced by the shop if the design be finalized.

1. Main shield
   1. Cost estimate of the roller-coaster system? Small top-part has ~ 8“x8”x32“ of Pb (~381 kg) plus 2”x8“x32” of Cu (~75 kg)
      A: Available off-the-shelf. The big question is how to prevent the stack of bricks that support rails from shaking/ falling apart.
   2. Cost estimate of the sliding handles and stripes?
   3. Cost of the frame for the main shield?
   4. Poly plates?
2. Glove-box
   1. Cost estimate of 32“x32”x30“ sealed Plexiglas (or other material?) box?
   2. Frame?
3. We need to machine W around the preamp. How easy is to machine W? Can Jon recommend tungsten supplier? Labor cost?
4. We need to machine Cu at the bottom of the detector can. Labor cost?

1. Let's assume that we have 0.5” thick clean Cu plates (8” x 14” and 14“ x 14”) and we want to make a 8” x 14” x 14” box with the door.
   1. How can we attach pieces together in a cleanest possible way (e.g. using as small as possible of other than clean Cu)?
      A: Welding them together is the cleanest way, though it will require some machining first. It will most likely take a couple of days to weld the box together.
   2. We want to minimize the amount of time Cu pieces spend above the ground. How quickly can the above suggested method be done?
      A: Very rough estimate is ~2-3 days
   3. We need the door that will be one of the box's sides and opens from top to bottom. What could be used to attach it to the bottom plate (again this should be as clean as possible)?
      A: There are couple of ways, e.g. use Cu pins. Shop engineer should be able to design it fairly quickly, but still will charge for his time.
   4. How can the door be locked at the top, so that it doesn't accidentally open? Additional requirement that the door can be easily opened by somebody operating in rubber gloves.
      A: see above
   5. Jon's reply:
      A rough estimate for the copper box we looked at is $1700. This would include some design time for a hinge and latch system, welding, and machining for hinge and latch. It assumes you would provide the material. The cost would increase if the plate edges and sizes are not suitable for welding.
      We could stitch TIG weld the edges of the 1/2” thick cu plates together. This could be done without adding any filler rod to the weld if the plate edges are machined square, straight, and have very sharp corners. We would probably use helium gas for shielding with a 2% Lanthanated tungsten electrode.
      If the cu plates require only machining for the door apparatus the entire time in the shop would be 2 to 3 days. If we need to do machining on all the plates to get them square and straight for welding it would add another day. If we know when the material is arriving we can make sure the design is done and set aside a couple people to work on it as soon as it arrives. We are not open Saturday or Sunday so we need to get it on a Monday or Tuesday. You should be able to ask the manufacturer how the edges of the plates are cut or finished.
      If you decide to proceed we can work together on a hinge and latch design that takes into account your restrictions (no room on sides, minimum room on top, etc).
      We may be able to make some tapered pins with a head on them to lock the front door in the closed position. A head could be turned on the pin so it would be easy to grab with gloves.
2. If we decide to get a plate of OFHC Cu plate with approximate dimensions of 32“x20”x0.75“ with the requirement that it should be manufactured from scratch and be shipped to us asap, can it be done through the shop? (Does casting from scratch remove efficiently cosmogenic activation???)
   A: Shop won't do this, we should contact the mill directly.