A. Q. R. Baron

An X-ray monochromator with 1.65 meV energy resolution

Abstract We report the performance of an X-ray monochromator having a 1.65 meV resolution at 14.413 keV and high throughput. A flux of 1.2 × 108 photons/s was obtained at a third generation synchrotron radiation source. This corresponds to 25% of the spectral density (photons/eV) of the incident X-ray beam within the 4.4 μrad monochromator acceptance. Application of the monochromator in studies of nuclear inelastic absorption is demonstrated.

A fast, convenient, X-ray detector

Abstract We investigate the response of 5 × 5 mm 2 silicon reach-through avalanche photodiodes followed by high bandwidth electronics to X-rays between 6 and 30 keV. In particular, we demonstrate high-dynamic range (∼10 9 ) with maximum count rates in excess of 10 7 Hz, and good, ∼20%, pulse-height resolution with the same amplification scheme. Single diodes have good efficiencies below 20 keV while a stack of diodes is shown to have better than 30% efficiency at 30 keV. The time resolution of these devices is about 1.6 ns. Application to nuclear scattering experiments with synchrotron radiation is discussed.

Beryllium and aluminium refractive collimators for synchrotron radiation

Be and Al refractive lenses with long focal lengths provide a simple and efficient method of collimating synchrotron radiation. The divergence of an undulator beam at SPring-8 is reduced from >11u2005µrad full width at half maximum without the collimators to <3u2005µrad downstream of the collimators. The Be collimators have almost no losses (∼90% transmission) while the Al collimators reduce the flux by a factor of two (∼45% transmission). Data are shown at 14.4 and 18.5u2005keV.