Description
The bulk insert is a key shielding-penetration component in the CSNS-II project. Its inner end faces directly toward the target center, while its outer end connects to the external environment; consequently, the neutron guide housed within the bulk insert cannot be locally adjusted near the target side. Thus, the design of the adjustment mechanism for the bulk insert is critical for ensuring the collimation accuracy of the neutron optical path and the feasibility of operation and maintenance.
For the bulk insert of the Liquid Neutron Reflectometer (LNR) in the CSNS-II project, a frame-type adjustment mechanism is adopted. The mechanism mainly comprises a support frame, a worm-gear remote adjustment system, and a fine-adjustment transition plate. The overall dimensions are 1198 mm in length, 578 mm in width, and 754 mm in height, with a total mass of approximately 2 tons. Equipped with one set of vertical (elevation) worm-gear adjusters and one set of horizontal worm-gear adjusters, the mechanism enables remote independent control of two elevation points and two horizontal points from the external side, with an adjustment range of no less than ±5 mm in each direction. In addition, two sets of dowel-pin positioning devices are incorporated in conjunction with the bulk insert to guarantee repeated positioning accuracy after installation. At present, the detailed design has been completed, and the mechanism is about to enter the manufacturing stage.
This abstract systematically presents the structural composition, functional parameters, and current status of the bulk insert adjustment mechanism, which may serve as a reference for the remote alignment design of similar shielding penetrations.
Key Words
Bulk insert, Adjustment mechanism, Neutron guide, Remote alignment