Facilities for surface analyses

Laboratory for the detailed examination of large series of niobium sheets for the production of superconducting cavities

The production of state-of-the-art superconducting accelerator cavities requires high quality niobium material. Therefore DESY developed and is using a special eddy current scanning device to search for inclusions in the Niobium sheet material. A total of almost 15,000 sheets delivered from different vendors were scanned for the European XFEL project. Also all sheets needed for the production of LCLS-II cavities were scanned at DESY. In-kind contributors to the ESS project profit as well from the existing infrastructure.

Niobium sheets are scanned at an operating frequency of 170 kHz. The achieved visible sheet's depth is approximately 500 µm, and the minimal detectable inclusion size is about 80 µm. The scanning result is used to fix the RF active surface i.e. the later inner side of the accelerating structure.

Metallurgy laboratory for the examination of material needed for the production of superconducting cavities

The quality control of Niobium material used for cavity production profits from the operation of a metallurgy laboratory at DESY. Long time expertise is used to study defects found during eddy current scanning. The control of essential niobium properties is of utmost importance for reaching high accelerating gradients and low cryogenic losses.

Typical material properties are investigated using the respective tools and methods. The procurement of large amounts of niobium sheets requires QC at both sides (producer and vendor).


DESY, Hamburg (Germany)


For further information please email: amici@desy.de.