There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

J. Appl. Cryst.の発刊に際して

The ability of dual- and multi-energy CT to differentiate materials of different effective atomic numbers makes possible several new and clinically relevant CT applications.

Dual- and Multi-Energy CT: Principles, Technical Approaches, and Clinical Applications

This review (over 380 references) summarizes metal–organic frameworks (MOFs), Materials Institute Lavoisier (MILs), iso-reticular metal–organic frameworks (IR-MOFs), porous coordination networks (PCNs), zeolitic metal–organic frameworks (ZMOFs) and porous coordination polymers (PCPs) with selected examples of their structures, concepts for linkers, syntheses, post-synthesis modifications, metal nanoparticle formations in MOFs, porosity and zeolitic behavior for applications in gas storage for hydrogen, carbon dioxide, methane and applications in conductivity, luminescence and catalysis.

MOFs, MILs and more: concepts, properties and applications for porous coordination networks (PCNs)

Photon counting detectors (PCDs) with energy discrimination capabilities have been developed for medical x-ray computed tomography (CT) and x-ray (XR) imaging. Using detection mechanisms that are completely different from the current energy integrating detectors and measuring the material information of the object to be imaged, these PCDs have the potential not only to improve the current CT and XR images, such as dose reduction, but also to open revolutionary novel applications such as molecular CT and XR imaging. The performance of PCDs is not flawless, however, and it seems extremely challenging to develop PCDs with close to ideal characteristics. In this paper, the authors offer our vision for the future of PCD-CT and PCD-XR with the review of the current status and the prediction of (1) detector technologies, (2) imaging technologies, (3) system technologies, and (4) potential clinical benefits with PCDs.

/pdf/vision-20-20-single-photon-counting-x-ray-detectors-in-2ozmq4m8yc.pdf

Vision 20/20: Single photon counting x-ray detectors in medical imaging

Single-crystal neutron-diffraction studies of Cd 0.96 Zn 0.04 Te, undoped (p and n) and doped CdTe (Cl and V), were performed using the high-resolution time-of-flight diffractometer OSIRIS. The d-spacing and integrated intensity of the (1 1 1) Bragg reflection were determined as a function of temperature. The results were analysed within the Debye approximation and the Debye temperatures calculated. Distinctive features are found according to the conductivity character of the sample and dopant used. This work confirms the reliability of neutron diffraction to obtain unique quantitative vibrational information.

The use of neutron diffraction in the quantitative characterization of dopant-dependent dynamical properties of semiconductors

100 μm thick layers of CdTe have been grown by Molecular Beam Epitaxy (MBE) on LEC GaAs (001) substrates. The
intended application for the CdTe thick films is the fabrication of radiation detectors. As recently reported
extensive characterization has been performed. In this paper the results of the previous papers are being summarized,
showing the potential of the CdTe films to be used as radiation detector. Furthermore first investigations on the
application of the layers as radiation detectors are being presented.

Characterization of thick layers of CdTe grown with MBE for the fabrication of radiation detectors

Much has been reported on the excellent performance of the Eu2+ activated SrI2-scintillator in spectroscopic applications, like the high light yield (97 660 ph/MeV) and good energy resolution (2.7% FWHM at 662 keV). The exploitation of these properties for other application fields is limited by the hygroscopic nature of the SrI2. Single crystal scintillating screens exhibit high spatial resolution, this combined with the high density, high effective atomic number, and the high light yield of the SrI2 could be used for high resolution X-ray imaging. Some of the questions we tried to answer in this work are the following: owing to the excellent performance of the SrI2-scintillator in spectroscopic applications, how would it perform in X-ray imaging applications. X-ray images are described based on their (spatial) resolution and contrast, how would they look like when recorded using the SrI2-scintillator detector. First a packaging technique was developed that protected the hygroscopic screens during the measurements. Our results show a high resolution of the images obtained with thin SrI2-scintillator screens both in 2D radiography and 3D tomography measurements. With these results, we think that the SrI2-scinitillator is not only a candidate for spectroscopic applications, but also for high resolution X-ray imaging purposes.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1946427413011433

High Resolution X-Ray Imaging with Thin SrI2-Scintillator Screens

We present a novel method which uses hole drift times in Coplanar Grid detectors to determine the interaction depth and identify multi-hit events Theoretical considerations in chapter II explain the method, furthermore a simple simulation is introduced Chapter III introduces a modified Coplanar Grid detector Chapters IV and V show and discuss experimental results regarding the drift time dependent depth correction

http://ieeexplore.ieee.org/iel7/6531926/6551044/06551974.pdf

Drift time dependent interaction depth correction in Coplanar Grid detectors

Due to the acquisition of up to two thousand projections, the radiation dose during computed tomography scans is severely higher, compared to planar radiographic imaging. Especially in medical diagnostics the minimization of the radiation dose a patient is exposed to, is of fundamental interest to reduce the appearance of radiation-induced damage. The use of photon-counting semiconductor detectors, like the Medipix3, in combination with iterative reconstruction algorithms, provides a possibility to achieve this objective. Therefore, measurements on phantoms are performed to determine the minimum amount of projections needed for the iterative reconstruction to work without the loss of spatial resolution and image contrast. We will show that it is possible to reduce the radiation dose necessary for computed tomography (CT) scans which will be a significant time saver and lower the cost of CT concerning material analysis. Regarding medical diagnostics, the reduction of the radiation dose can lead to a diminishing in the appearance of radiation-induced damages.

Investigation of the radiation dose in computed micro tomography using the Medipix3 semiconductor detector in combination with an iterative reconstruction algorithm

Michael Fiederle

Papers

The use of neutron diffraction in the quantitative characterization of dopant-dependent dynamical properties of semiconductors

Characterization of thick layers of CdTe grown with MBE for the fabrication of radiation detectors

High Resolution X-Ray Imaging with Thin SrI2-Scintillator Screens

Drift time dependent interaction depth correction in Coplanar Grid detectors

Investigation of the radiation dose in computed micro tomography using the Medipix3 semiconductor detector in combination with an iterative reconstruction algorithm