APS undulator radiation—first results

Design of an Undulator White Beam Profiler and Test Results on the APS Beamline

Performance challenges for an undulator XBPM during operation are contamination of the signal from the neighbouring bending-magnet sources and the sensitivity of the XBPM to the ID gap variations. Problems are exacerbated because users change the ID gap during their operations, and hence the percentage level of the contamination in the front-end XBPM signals varies. The smart XBPM system partia...

Undulator Radiation - First Results

High Accuracy Momentum Compaction Measurement for the APS Storage Ring with Undulator Radiation

We developed a new technique to measure the electron beam energy centroid and spread. It takes advantage of a sharp feature in the Advanced Photon Source (APS) diagnostic: undulator spectrum, the drop-off in the angle-integrated flux near its fundamental photon energy. The measurement technique has a high resolution and is nearly independent of the storage ring lattice functions. In this work, ...

Biological XAFS at the BioCAT Undulator Beamline 18ID at the APS

The Biophysics Collaborative Access Team (BioCAT) undulator beam line at the Advanced Photon Source, Argonne, IL is a user facility devoted to the study of partially ordered and disordered biological materials by X-ray scattering, diffraction and absorption spectroscopy. Two sagital focussing, double-crystal (Si(111) and Si(400)) monochromators and a 1 mmirror provide monochromatic, horizontall...

Measurement of the Aps Storage Ring Electron Beam Energy Spread Using Undulator Spectra

Abstract The angle-integrated flux spectrum of an undulator has sharp dropoffs at harmonic photon energies. Its derivative therefore shows pronounced peaks with rms width ∆ω/ω ~ 0.4/nN, where ω is the photon energy, n is the harmonic number, and N is the number of undulator periods. For the fundamental photon energy of the Advanced Photon Source diagnostics undulator, the derivative of the angl...