Introduction

The patented invention is a detector configuration for measuring the X-rays emitted by a sample irradiated by a source whose X-ray beam passes through a hole positioned in the detector itself, in order to maximise the collection of X-rays on the sensor.
Unlike already known solutions, the special arrangement of the sensing units allows optimal collection of the radiation emitted by the sample, subtending an overall larger and more uniform solid angle.

Technical features

A well-known configuration of this type of detector, which consists of several sensitive elements, is based on the arrangement of these elements on a plane on which the hole through which the X radiation passes is positioned. However, in such a configuration, the sensitive units furthest from the hole collect X-rays at a lower solid angle than the units closest to the hole. In the proposed configuration, on the other hand, the sensing units are arranged on a curved surface, optimally inclined with respect to the object from which the X-rays are to be collected and, thus, achieving an overall greater and more uniform solid angle.
The project has been developped over the past two years and is now in TRL 4: the first prototype consisting of a 450 μm thick four-channel SDD are glued onto the electronic readout circuit board has already been built in the laboratory. This prototype has been characterised by showing energy resolution performance in line with expectations: 129 eV at 2 μs peaking time and 175 eV at 32 ns, demonstrating the ability to preserve excellent energy resolution at high counts.

Possible Applications

• X-ray detection systems used for synchrotron light experiments;
• Analytical instrumentation for scientific and industrial applications on X-ray measurement (e.g. XRF – X-ray Fluorescence) using conventional sources such as X-ray tubes and electron beams (SEM – Scanning Electron Microscope).

Advantages

• Optimum inclination of the sensitive units for better X-ray collection;
• Greater solid angle subtended;
• More uniform solid angle between units;
• Great ability to operate at high count rates;
• Ability to optimise overall detector efficiency and maximise event count rate.