Generation of x-ray radiation in a storage ring by a superconductive cold-bore in-vacuum undulator

Abstract

The first beam measurements with a cold-bore superconducting in-vacuum undulator in a storage ring are reported. Undulators are x-ray generators in light sources. The physical limitations of these devices limit the intensity and the brilliance of the x-ray beam. At present the undulators are made from permanent magnets. It was shown in earlier papers that at low electron beam intensities superconductive wires in the vacuum beam pipe can overcome the limitations inherent to permanent magnet undulators. It was argued that the use of these novel devices in light sources with high beam currents may be limited by the extreme anomalous skin effect regime in Cu at 4.2 K, which has so far undergone very little investigation, and the power deposited by the infrared part of the synchrotron radiation. The purpose of this paper is to present measurements of these effects at the synchrotron light source ANKA with stored currents up to 200 mA.

Miniature magnetic devices for laser-based, table-top free-electron lasers

“…The smallest prototype of the Karlsruhe group ( u 3:8 mm) based on NbTi wires reached peak fields of around 1 T for a gap of 1 mm [28]. Recent results achieved [29] with an in-vacuum, u 14 mm, and g= u 0:6 undulator indicate an improvement of about 20% compared to conservative hybrid designs and no improvement over the one presented here. However, there is room for future coil development based on Nb 3 Sn that might allow for comparative K-values and the desired increase in the gap height [30] by a factor of about 1.5.…”

Cold vacuum chamber for diagnostics: Instrumentation and first results

“…The 50 μm of copper plating resembles the surface seen by the electron beam in the liners used in the ANKA superconducting undulators, made of 300 μm stainless steel foil with 30 μm of copper plating [11,18]. The temperature of the liner in different superconducting IDs ranges from around 4-20 K [1,4,19]. In order to simulate the cold bore of superconducting IDs, the liner must be cooled down to reach the above mentioned temperature range.…”

“…Cold bore superconducting wigglers [1][2][3] and an undulator [4] installed in different storage rings have been used also to estimate the beam heat load; however, none of those IDs was designed and built to perform beam heat load diagnostics and some of the measured parameters might be affected by significant errors. The resistive wall heating model nicely reproduces the measured values of the beam heat load to the cold beam pipe of the superconducting undulator built by ACCEL Instruments GmbH, Bergisch Gladbach, Germany, at the synchrotron light source ANKA in the so-called low alpha operation mode of the machine, where the electron bunches are shortened to a few ps [5] to generate coherent synchrotron radiation [6].…”

Shaping Photon Beams with Undulators and Wigglers

“…Several CPMUs are in operation today. Since 2005, the first super conducting undulator (SCU) is operated in a storage ring under user mode conditions (Casalbuoni et al 2006). Another SCU was recently installed at the APS (Ivanyushenkov et al 2014).…”