LDX Project Status
December 12, 2002
Ability Engineering Technology completed several steps in the final assembly of the radiation shield and outer vacuum vessel of the floating coil cryostat. Fiberglass joints were applied on the midplane to enhance the shield's structural integrity. All heat exchange tubings were connected and tested successfully for leaks.
The bayonet and electrical feedthrough receptacles on the cryostat vacuum shell were installed and the space frame was prepared for final installation. The female bayonets for the cryostat were welded to 90 degree tube elbows, leak tested at MIT, and sent to Ability Engineering to be welded into the cryostat ports.
All 24 laminated metal supports of helium vessel were modified so as to provide higher thermal resistance. The supports were coated with a thin layer of very fine magnesium oxide powder (particle size ~1.75 microns).
The helium vessel has been fully welded and leak tested. All leaks were re-welded. The helium vessel was centered and assembled permanently with a support ring utilizing a girder of 16 G10 tubes.
Unfortunately, the vendor who will install the cryopanels at the lower end of the radiation copper shield had damaged one quarter of the shield during the welding of copper boxes which will contain the getter. After examination, the damaged quarter shield was returned to the vendor, and acceptable repairs have been completed. Sintez has developed a technology for the welding of the boxes to the cryopanels for the copper shield without creating a distortion of the shield shape or surface finish.
The cryostat is presently being pre-assembled. The helium vessel, lower radiation shield, inner and outer nitrogen cans have been installed at the bottom of the cryostat. The upper radiation shield will next be adjusted and outer vacuum vessel pre-assembled.