TWOCRYST Hardware

The TWOCRYST Combined Long Crystal (TCCP) and Target Goniometer

One of the key hardware elements enabling the TWOCRYST experiment is the custom-built goniometer for the long bent crystal, part of the TCCP (Target Collimator Crystal Precession) assembly. This highly specialized device was conceived, designed, and constructed in only two years, a remarkable achievement given the mechanical precision and complexity involved.

The goniometer was engineered to fulfill two primary motion tasks: precise linear translation and angular rotation of the long bent crystal. It delivers micrometre precision in linear motion (5 μm) and an angular resolution of 0.1 μrad. Projected into the macroscopic world, the angular precision corresponds to an offset of only 1mm over a length of 10km! This level of precision is essential for aligning the crystal with the LHC beam and enabling particle channeling.

Integrated directly into the goniometer is a tungsten target, placed just 0.2 mm from the crystal. This target can be independently moved into or out of the beam path without interfering with the crystal alignment. Fitting two independently movable elements into such tight spatial constraints, while maintaining micron-level stability under beamline conditions, pushed the limits of mechanical design and demanded unprecedented engineering.

A photo set showing the goniometer and the team behind its development and construction can be viewed on the CERN Document Server: cds.cern.ch/record/2921818.

_{Photo: Marina Cavazza / CERN}