Dietmar Sundermann

Nondestructive chemical identification using an x-ray transmission function obtained with the multi-energy method

In this paper a new kind of process of ranking x-ray transmission information in the range 20 - 150 keV is described. This ranking method can be applied to other energy ranges and to other particles. Based on a classical statistical method, Principal Component Analysis, it can be applied to continuous transmission measurement as multi- energy method. In this case, the effective Z sensitivity is in the neighboring of 0.001, i.e. 5 times better than the classical dual-energy method. A x-ray imaging application: the explosive device detection systems of Heimann systems is described using both multi-energy model and this ranking process. It provides good quality radiographic images and accurate chemical identification. The entire methodology described in the article is covered by three international patents.

Gaseous x-ray detectors to examine freight containers and vehicles

The Schlumberger SYCOSCAN is a radioscopic control system designed to inspect freight containers and vehicles by X-rays. The X-ray detection is based on a modified version of a multiwire proportional chamber (MWPC) patented by Schlumberger. The MWPC principle was discovered by 1992 Physics Nobel Prize Winner G. Charpak. We present the detectors working principle. It presents simultaneously a high spatial resolution, a good detection efficiency, a high intrinsic gain and high dynamics. We will compare the SYCOSCAN detector to conventional scintillator/photodiode combinations.

Multi-energy method: a new approach for measuring x-ray transmission as a function of energy with a Bremsstrahlung source and its application for heavy element identification

The purpose of this article is to describe a new methodology for analyzing x-ray transmission. This new technique is called the multi-energy method and is a generalized application of traditional dual-energy methods. This method can be used with broad or line spectra, with photons or other particle and on a large energy range e.g. for photons from 20 keV to higher than 10 MeV. The application of this method in the range 20 to 150 keV with Bremsstrahlung spectra is very fast and allows a precision better than 0.5% on the coefficient of attenuation of photons over a large atomic number range (1 to say 40) and over a large thickness range (< 20 g/cm2). This method, described in the article, protected by two international patents, is applied point by point in the explosive device detection system of Heimann Systems, commercially available under the name of XCalibur.