A superconducting switch for insertion devices with variable period length

Superconducting insertion devices (IDs) are very attractive for synchrotron light sources since they offer the possibility to enhance the tuning range and functionality significantly by period length switching. Period length switching can be realized by reversing the current in a separately powered subset of the superconducting windings. So far, the first demonstration mock-up coil allowing period length tripling was fabricated and tested successfully. Here, we report on the feasibility of superconducting switches built to operate in a liquid helium bath and under conduction cooled conditions

Beam heat load analysis with COLDDIAG: a cold vacuum chamber for diagnostics

The knowledge of the heat intake from the electron beam is essential to design the cryogenic layout of superconducting insertion devices. With the aim of measuring the beam heat load to a cold bore and understanding the responsible mechanisms, a cold vacuum chamber for diagnostics (COLDDIAG) has been built. The instrumentation comprises temperature sensors, pressure gauges, mass spectrometers and retarding field analyzers, which allow to study the beam heat load and the influence of the cryosorbed gas layer. COLDDIAG was installed in the storage ring of the Diamond Light Source from September 2012 to August 2013. During this time measurements were performed for a wide range of machine conditions, employing the various measuring capabilities of the device. Here we report on the analysis of the measured beam heat load, pressure and gas content, as well as the low energy charged particle flux and spectrum as a function of the electron beam parameters