Superconducting Undulator Test Facility at BNL

Superconducting Undulator Test Facility at BNL John Skaritka, Payman Mortazvi, George Rakowsky Workshop on Superconducting Undulators &Wigglers The European Synchrotron Radiation Facility Grenoble, France June 30-July 1 2003

Superconducting Undulator Test Facility at BNL Superconducting Undulator (SCU) development is of critical importance for the proposed NSLS II upgrade. BNL is a member of the US collaboration for SCU technology development. BNL s primary role is to Test prototype SCU s that are constructed by members of the collaboration. The National Synchrotron Light Source and Collider Accelerator departments shall contribute resources to establish a SCU test facility at BNL. The Facility shall perform testing that will address the requirements of the collaboration members as well as simulate an operating environment to evaluate SCU performance..

Superconducting Undulator Test Facility at BNL CAD s Magnet division has contributed the use of an approx. 2M vertical dewar and shall supply cryogens from the refrigerator systems in BLDG.902. NSLS shall develop apparatus to perform magnetic measurements and performance testing of SCU prototypes. The SCU prototypes can be operated in pool boiling helium or a vacuum. The first SCU prototypes shall be less them 0.45 meters in length. Future magnets shall require a deeper dewar or a horizontal test system. Conceptual design of a 1 meter long expandable horizontal test system is underway.

Magnetic Measurement Facilities at the National Synchrotron Light Source 2.5 m Hall Probe Bench Moving-Wire Integrated Multipole Bench 2 m Pulsed-Wire Bench Dedicated to measurement of Insertion Devices and (warm) beam transport and special-purpose magnets (More information in talk by G. Rakowsky )

2 Meter Pulsed Wire Bench during shimming of a 1 Meter segment of the VISA Undulator

Electron Trajectory as measured in an unshimmed VISA undulator segment Electron Trajectory in shimmed VISA undulator segment as measured by the pulsed wire system

Experience With Undulator Magnetic Measurement Techniques. Hall Probe mapping of a superconducting undulator magnet experience or High Gain Harmonic Generator (HGHG) undulator 1993-1995. Cryogenic surface mount hall probes are made by Lakeshore Model HGT-2100. Specifications Input resistance: 450 to 900 ohms Output resistance: 550 to 1350 ohms Nominal control current: 5 ma Max continuous current: 10 ma Magnetic Sensitivity (1C = 5 ma): 55 to 140 mv/kg Overall size:.15 mm x.17 mm x.7mm Chip size: 0.012 mm x.012 mm Horizontal pulsed wire system developed at the NSLS has measured a variety of conventional undulator designs. Mini-gap undulator Micro-gap undulator Individual 1 meter segments of the VISA undulator Multiple meter segments of the VISA undulator assembly Work is under way to develop a pulsed wire system to be used in the vertical testing of superconducting undulator prototypes Conceptual design of a horizontal pulsed wire test bed for superconducting magnets is being considered

Simplified Schematic of the Hall Probe Array Mapping System to be used in the Vertical SCU Test Facility

Views of Hall Probe Array Insert for use in the Vertical SCU Test Facility Hall Probe System Dewar Insert Hall Probe Insertion Wand Z Stage Probe Drive Vacuum Chamber Extension Cryogenic Hall Probe Array on G10 Backing Strip Undulator Beam Tube

Cut Away view of Test Dewar in Hall Probe Configuration Hall Probe Array position control Z-stage Vacuum Chamber position control X-Y stage Test Dewar/Vacuum Chamber

Close up of Cut Away View of Hall Probe of Hall Probe Mapping of a Prototype Superconducting Undulator Hall Probe Drive Wand Hall Probe Array Cold Calibration Coil

Simplified Schematic of the Pulsed Wire System to be developed for the Vertical SCU Test Facility

Views of Pulsed Wire System for use in Vertical SCU Test Facility Vertical Pulsed Wire System Dewar Insert Pulsed Wire Vacuum Jacket Wire Finder Adjustment X-Y Stage Pulsed Wire Vacuum Jacket Wire Finder Laser Diode Tube 2.8 mm diameter pulse wire reaction Tube Inside Undulator Vacuum Chamber

Pulsed Wire Top Hat Configuration Pulsed wire stages Dewar Top-Hat with heat shields & feedthroughs Vapor cooled Current leads Undulator prototype

Pulsed wire tension control Pulsed Wire Feed-through Wire finder adjustment X-Y stage Vacuum chamber locator X-Y stage

View of Pulsed Wire System Inserted into the Vertical Dewar

Conceptual Design of a Horizontal Test Facility for SCU s Utilizing both Pulsed Wire and Hall Probe Systems

Summary Presented was a description of BNL s efforts toward the development of a Vertical Test Facility that will perform magnetic measurements and magnet performance testing for superconducting undulator prototype magnets that will be developed by BNL and other members of the US Laboratory Collaboration. Presented are the designs of the magnetic measurement systems that are under development at BNL for the Superconducting Undulator Magnet Program.