Superconducting Undulator (SCU) R&D for Free-Electron Laser (FEL) Systems (Argonne) Highlights October 1-31 and November 1-30, 2015 – Measured the gap and correlate the measured to the physical gap. Began measuring using the LNBL pulsed-wire system. SCU Magnet and Test Cryostat Fabrication: The SCU system was warmed up, and the cryostat end covers were removed in order to measure the magnet gap, shown schematically in Figure 1, using the Capacitec Gapman Gen3 Portable Electronic Feeler Gauge shown in Figure 2. Results of the gap measurement are shown in Table 1 in µm. Values in the table are the sum of the gap between each core and the vacuum chamber at each torque. The center clamp was torqued to 60 in-lbs for all measurements. A thin layer of epoxy on the poles affects the absolute values of the gap measurement. Figure 1: A schematic representation of the two cores viewed from the side. For clarity, the vacuum chamber is not shown. The upstream (US) and downstream (DS) ends are shown, as are the 6 measurement points referenced in Table 1. Figure 2: Photo of the Capacitec device used to make these measurements. Specifications and performance information can be found at: Table 1: Measured gap at each point shown in Figure 1. The end covers were then reinstalled and the SCU system was cooled down for magnetic measurement. Figure 3 shows measured peak fields and gaps along the device, and phase errors are shown in Figure 4. Figure 3: Peak fields measured along the device are shown in the upper plot, and can be compared to the measured gap deviations shown in the lower plot. Figure 4: Phase errors as a function of current. a) b) c)
Superconducting Undulator (SCU) R&D for Free-Electron Laser (FEL) Systems (Argonne) Highlights – October 1-31 and November 1-30, 2015 Measured the gap and correlate the measured to the physical gap. Began measuring using the LNBL pulsed-wire system. SCU Magnet and Test Cryostat Fabrication: The SCU system was warmed up, and the cryostat end covers were removed in order to measure the magnet gap, shown schematically in Figure 1, using the Capacitec Gapman Gen3 Portable Electronic Feeler Gauge shown in Figure 2. Results of the gap measurement are shown in Table 1 in µm. Values in the table are the sum of the gap between each core and the vacuum chamber at each torque. The center clamp was torqued to 60 in-lbs for all measurements. A thin layer of epoxy on the poles affects the absolute values of the gap measurement. Figure 1: A schematic representation of the two cores viewed from the side. For clarity, the vacuum chamber is not shown. The upstream (US) and downstream (DS) ends are shown, as are the 6 measurement points referenced in Table 1. Figure 2: Photo of the Capacitec device used to make these measurements. Specifications and performance information can be found at: Table 1: Measured gap at each point shown in Figure 1. The end covers were then reinstalled and the SCU system was cooled down for magnetic measurement. Figure 3 shows measured peak fields and gaps along the device, and phase errors are shown in Figure 4. Figure 3: Peak fields measured along the device are shown in the upper plot, and can be compared to the measured gap deviations shown in the lower plot. Figure 4: Phase errors as a function of current. a) b) c)
ANL-Report-15NOV15.docx