natural radionuclides present in soil as well as certain anthropogenic radionuclides released to the environment are the major contributors to terrestrial outdoor exposures. in the assessment of human exposures from environmental radioactivity, besides the conventional method of soil and vegetation sampling combined with laboratory based analyses of environmental media, the other choice would b...

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine...

Monte Carlo (MC) calculated detector-specific output correction factors for small photon beam dosimetry are commonly used in clinical practice. The technique, with a geometry description based on manufacturer blueprints, offers certain advantages over experimentally determined values but is not free of weaknesses. Independent MC calculations of output correction factors for a PTW-60019 micro-di...

In this article we demonstrate the performance of a direct conversion amorphous selenium (a-Se) X-ray detector using biphenyldisnhydride/1,4 phenylenediamine (BPDA/PPD) polyimide (PI) as a hole-blocking layer. The use of a PI layer with a-Se allows detector operation at high electric fields (≥10 V/μm) while maintaining low dark current, without deterioration of transient performance. The hole m...

A 2D photon-counting X-ray detector system with 1.4 kHz frame rate and 55 μm spatial resolution has been developed and commissionned on ESRF beamlines. The system called MAXIPIX (Multichip Area X-ray detector based on a photon-counting PIXel array) consists of a detector module implementing up to five MEDIPIX-2 or TIMEPIX photon-counting readout chips, a custom readout interface board and a Lin...

Large area detectors capable of operating with high detection efficiency at energies above 30 keV are required in many contemporary X-ray imaging applications. The properties of high Z compound semiconductors, such as CdTe, make them ideally suitable to these applications. The STFC Rutherford Appleton Laboratory has developed a small pixel CdTe detector with 80×80 pixels on a 250 μm pitch. Hist...

Significant advancement in thin-film cadmium telluride (CdTe) deposition techniques in recent years has made this material attractive for the development of low-cost large area detector. Here we evaluate the intrinsic performance of the detector for a range of energies relevant to diagnostic imaging applications, such as fluoroscopy. The input x-ray spectra for a set of tube potentials ranging ...

The development of a novel energy resolved fast Xray imaging detector is reported. The device is based on pixellated cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) detectors coupled to a custom designed 16-channel fast spectroscopy front-end electronic circuit. For each channel, a fast Analog to Digital Converter (ADC) continuously digitizes the signal from the detector pixel. A F...

Introduction Detector description and its principle of operation Detector module. Detector Features and its Performance EDXRF of Fe 55 Spectrum Detector comparison with Silicon Drift Detector SDD Concluding remarks References A Silicon Lithium Si(Li) detector is presented. The detector structure and its working principle are explained. The detector is cooled to 77o K by liquid Nitrogen. The det...