We summarize the results of a number of hard X-ray measurements on cerium-doped LaCl3 and LaBr3 scintillators. The experiment was carried out at the HASYLAB synchrotron radiation facility using highly monochromatic pencil beams across the energy range 10.5–100keV. Additional full-area measurements were carried out using radioactive sources. All measurements were carried out at room temperature. The measured FWHM energy resolutions (ΔE/E) under pencil beam illumination were 29% (LaBr3) and 32.4% (LaCl3) at 10.5keV falling to 7.8% (LaBr3) and 9.2% (LaCl3) at 100keV. At 662keV, the energy resolutions were 3.9% and 3.0% FWHM. The proportionality of the energy responses shows marked deviations from linearity above and below the La edge at 39.8keV. At the edge the energy response changes by 3%. Fine structure across the edge was also investigated using single photon count rate measurements taken in 1eV steps across the edge. The data show considerable near-edge structure when compared to curves generated from standard atomic data tables. However, very little evidence was found for extended X-ray fine structure suggesting that the bulk of the structure arises from the local coordination environment.

We report on the detection of hard X-rays using a GaP Schottky diode at the HASYLAB synchrotron radiation research facility. Exposure to alpha particles from an 214 Am source showed that the device was spectroscopic at room temperature with a FWHM energy resolution of 3.5 % at 5.5 MeV. It was also found to be responsive to X-rays in the range 11-100 keV. Although individual energies are not spectrally resolved there is a proportionality of response to increasing X-ray energy. A two-dimensional scan of the sensitive area using a 30 x 30 mu m(2) 30 keV pencil beam showed the spatial response of the detector to be uniform at the few percent level, consistent with statistics. (c) 2007 Elsevier B.V. All rights reserved.

We describe an inexpensive beam monitor for hard X-ray synchrotron applications which has good spectroscopic abilities and can operate without cooling. The device is centred on an inexpensive, commercial off-the-shelf, large area (1.2 × 1.2 mm2) Si photodiode operated in single counting mode. Measurements carried out at the HASYLAB synchrotron research facility have shown that it is fully spectroscopic across the energy range 8 keV to 100 keV with a measured energy resolution of ∼ 1.2 keV FWHM at room temperature. The measured resolutions were found to be the same under pencil-beam and full-area illumination, indicating uniform crystallinity and stoichiometry of the bulk. The low cost, simplicity and performance of the detector make it suitable for a wider range of applications, e.g., in undergraduate laboratory experiments.