Investigation of Magnetic–field-induced Temperature Error of Pt- 500

The parallel and perpendicular magnetic field behaviour of five industrial grade platinum resistance thermometers (Pt 500) has been investigated. Measurements on the sensors were performed at various temperatures between 300 K and 4.2 K in the presence of intense static magnetic fields up to 9 T. The sensor performances were studied for perpendicular and parallel magnetic field. The field dependent temperature errors (DT/T) and the relative magneto resistance changes (DR/R) are tabulated as a function of field and the temperature

Prototype modular cryostat utilized for 10 MW offshore superconducting wind turbine

Publisher Copyright: © 2017 International Institute of Refrigeration. All rights reserved.Karlsruhe Institute of Technology (KIT) has designed the cryogenic cooling system for a 10 MW superconducting generator (SCG) for offshore wind turbines. The cooling system adopts the cryogen-free and modular concept. A modular cryostat, that enables each of 48 coils in the SCG to work at cryogenic temperatures of 20 K, provides an advantage of easy transportation, installation, and maintenance in the offshore environment. Furthermore, with the modular design the 10 MW SCG concept can be validated through a scale-down model. This paper describes the development of a prototype modular cryostat and the preliminary cool down by a two stage Gifford-McMahon cryocooler through conduction cooling. The dummy coil made of copper enveloped in the cryostat could reach a temperature of 9 K after 56.5 hours. The encouraging experimental results agree well with the numerical simulation. Numerical model and test results are presented.This research is primarily supported by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement 308793. Special thanks are extended to Jose Mari Merino, Ainhoa Pujana andPeer reviewe

Heat loads measurements at the XFEL cold linac

Abstract. The European X-Ray Free Electron Laser (EuXFEL) at DESY is in operation sincethe beginning of 2017. The free electron laser is based on a superconducting linear acceleratorthat delivers electrons to the undulator section with beam energy up to 17.5 GeV. The linearaccelerator consists of 96 cryomodules; each 12 m long module is an assembly of8 superconducting cavities and one superconducting magnet. This paper focusses on themeasurement of the static and dynamic heat loads of the cryomodules assembled in the linac.Heat loads are an important parameter to evaluate the efficiency of the refrigerator system, thequality of the cryomodule assembly and installation and the accelerating cavity performances,being the dynamic heat loads proportional to the cavity quality factor (Q0, the ratio of the storedenergy to the dissipated energy). The paper describes at first the procedure to measure the staticheat load without beam energy and the dynamic heat loads at different beam energy levels. Themeasurement results are then summarized and compared with the XFEL design values

Loss of insulation vacuum tests on an EuXFEL cryomodule

Many Free Electron Lasers (FEL) are nowadays based on linear superconducting accelerators (linacs). The typical layout of such a linac consists of a number of cryomodules (CMs) arranged in strings. Each cryogenic circuit in a string is protected by safety valves (SVs) in case of failure of the system or a catastrophic event. A typical worst-case scenario considers the venting of the insulation vacuum, causing a fast and uncontrolled warm up of the cryogenic circuits. Such venting can for example take place across a pump port belonging to a string. The amount of heat deposited on each circuit is a very important parameter to correctly size the safety devices. This paper describes the tests performed at DESY on an EuXFEL cryomodule to evaluate the heat input to the three cryogenic circuits of the CM while venting the insulation vacuum. Test results are given with a particular focus of their application to long strings