Different power supplies for different machines

Each time a new accelerator is built, the question of the right choice of technology for the power supplies (PS) is raised again. No specific advice can be given since the demands on the units as well as the available budget have a strong influence on the decision. An overview of the different technologies in the different machines is given here. On account of the large number of different applications, not every solution can be mentioned here but examples of different power supplies are shown. The categories are fast cycling machines, fast ramping machines, slow ramping machines, pulsed machines, and constant-power power supplies

SUNDAE2 at EuXFEL: A Test Stand to Characterize the Magnetic Field of Superconducting Undulators

European XFEL foresees a superconducting undulator (SCU) afterburner in the SASE2 hard X-ray beamline. It consists of six 5m-long undulator modules with a 5mm vacuum gap, where each module contains two 2m-long coils and one phase shifter. Prior to installation, the magnetic field must be mapped appropriately. Two magnetic measurement test stands named SUNDAE 1 and 2 (Superconducting UNDulAtor Experiment) are being developed at European XFEL. While SUNDAE1 will be a vertical test stand to measure SCU coils up to two meters with Hall probes in a liquid or superfluid helium bath, SUNDAE2 will measure the SCU coils assembled in the final cryostat. This contribution presents the development status of SUNDAE2 and its main requirements

Conceptual Design of a Liquid Helium Vertical Test-Stand for 2m long Superconducting Undulator Coils

Superconducting Undulators (SCUs) can produce higher photon flux and cover a wider photon energy range compared to permanent magnet undulators (PMUs) with the same vacuum gap and period length. To build the know-how to implement superconducting undulators for future upgrades of the European XFEL facility, the test stand SUNDAE1 for the characterization of SCU is being developed. The purpose of SUNDAE1 is the training, tuning and development of new SCU coils by means of precise magnetic field measurements. The experimental setup will allow the characterization of magnets up to 2m in length. These magnets will be immersed in a Helium bath at 4K or 2K temperature. In this article, we describe the experimental setup and highlight its expected performances

SUNDAE1: A Liquid Helium Vertical Test-Stand for 2m Long Superconducting Undulator Coils

Superconducting Undulators (SCUs) can produce higher photon flux and cover a wider photon energy range compared to permanent magnet undulators (PMUs) with the same vacuum gap and period length. To build the know-how to implement superconducting undulators for future upgrades of the European XFEL facility, two magnetic measurement test stands named SUNDAE 1 and 2 (Superconducting UNDulAtor Experiment) are being developed. SUNDAE1 will facilitate research and development on magnet design thanks to the possibility of training new SCU coils and characterizing their magnetic field. The experimental setup will allow the characterization of magnets up to 2m in length. These magnets will be immersed in a Helium bath at 2K or 4K temperature. In this article, we describe the experimental setup and highlight its expected performances

Applying the ALARA concept to the evaluation of vesicoureteric reflux

The voiding cystourethrogram (VCUG) is a widely used study to define lower urinary tract anatomy and to diagnose vesicoureteric reflux (VUR) in children. We examine the technical advances in the VCUG and other examinations for reflux that have reduced radiation exposure of children, and we give recommendations for the use of imaging studies in four groups of children: (1) children with urinary tract infection, (2) siblings of patients with VUR, (3) infants with antenatal hydronephrosis (ANH), and (4) children with a solitary functioning kidney. By performing examinations with little to no radiation, carefully selecting only the children who need imaging studies and judiciously timing follow-up examinations, we can reduce the radiation exposure of children being studied for reflux

Electronic Logbook

The DESY MKK shift crew is responsible for magnet power supplies, HV supplies for RF transmitters, watercooling and air conditioning systems, the HV and LV mains of entire DESY. To keep track of the failures of these systems an electronic logbook was developed. The content of the logbook is available to the maintenance groups giving them the possibility to comment on failures to help in future troubleshooting. Via different filters andsearch functions it is possible to select failure types, detect multiple tripped components and get a good statistic of trips to see whether systematic failures occur. Hence an early detection is possible and preventive maintenance on these components can be done. The logbook was developed using ORCALE RDBMS (Relational Database Management System), and uses other databases to get information about the built incomponents as e.g. magnet power supplies. It is in use for more than one year with a large acceptance of the shift members

Long Pulse Modulators

Long pulse modulators are used to produce high-voltage, high-power pulses with durations of several hundred microseconds up to some milliseconds. The loads are one or more klystrons for producing RF power to accelerate the particle beam in superconducting cavities. After years of development and improvements in different institutes a variety of topologies exist, and are presented. The basics of modulators, pulse requirements and klystrons are explained. Additionally, the charging of internal energy storage will be addressed. The outlook for future developments is given.Long pulse modulators are used to produce high-voltage, high-power pulses with durations of several hundred microseconds up to some milliseconds. The loads are one or more klystrons for producing RF power to accelerate the particle beam in superconducting cavities. After years of development and improvements in different institutes a variety of topologies exist, and are presented. The basics of modulators, pulse requirements and klystrons are explained. Additionally, the charging of internal energy storage will be addressed. The outlook for future developments is given