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.

The photograph below (12-4-02) shows the coil installed within the LHe vessel, the outer vacuum vessel, and a quadrant of the LN2 radiation shield.

According to the corrected schedule, the fully manufactured C-coil will be installed at the Sintez test stand at the end of this year. The magnet will be cooled and filled with liquid helium by February 1. The acceptance test of the C-coil is now scheduled to take place February 3-10.

Sintez has developed a device for mapping the magnetic field inside the warm bore of the cryostat. This will provide MIT with the required information as to the position of magnetic axis and the center of the C-coil with respect to the cryostat outer walls.


Components for the L-coil cryostat construction have begun to arrive at Everson. These include several components that were fabricated in MIT/PSFC machine shops.  

The stock for the thermal links (connecting the cold head to the L-coil and the cold head to the coil's HTS leads) has been received at Everson and machining of the component pieces has begun. The component pieces needed to complete the coil assembly and to suspend the L-coil from the cryostat cover plate are in-hand, as is the lower portion of the radiation shield. These components will be assembled once the thermal links are complete.

MIT has reviewed the assembly procedures and discussed how best to incorporate sensor installation and lead wire routing into the assembly procedures.


Cleaning of the vacuum-facing components is nearly finished. The procurement of the pneumatic components required for the initial tests is underway.