Theofanis Pantazis

• University of Wollongong

In-situ X-ray fluorescence analysis (XRF) of ancient artifacts from the excavation area was performed using a novel X-ray instrumentation, composed of a portable silicon PIN thermoelectrically cooled X-ray detector, a miniature X-ray source, and portable data acquisition devices. The main objective of the analyses in Akrotiri was to explore the pot...

Most energy-dispersive X-ray fluorescence (EDXRF) instruments use Si diodes as X-ray detectors. These provide very high energy resolution, but their sensitivity falls off at energies of 10–20 keV. They are well suited for measuring the K lines of elements with Z < 40, but for heavier elements, one must use K lines at low efficiency or use L or M li...

Thermoelectrically cooled X-ray detectors are widely used in both portable and laboratory X-ray spectrometers. The most common detectors are fully depleted 500 µm devices behind a Be window to provide a vacuum tight enclosure. These provide good resolution and efficiency for characteristic X-rays from 2 keV to about 20 keV but a larger energy range...

Portable/hand-held X-ray fluorescence (XRF) instruments now achieve performance comparable to laboratory-sized, expensive, liquid nitrogen cooled systems. The availability of these systems has expanded XRF applications out of the laboratory to in situ analysis including that for lead in paint, alloy identification, process control, restriction of h...

The accuracy and precision of energy dispersive X-ray fluorescence (EDXRF) improve with improved detector energy resolution. However, there are always trade-offs between the highest energy resolution and the highest count rates, there are practical difficulties in achieving the very best energy resolution, and there are many system level issues bey...

The VeriSpreaderTM radiation detection system will monitor every container passing through a shipping terminal without impeding the flow of commerce by making the radiation measurements during normal container handling. This is accomplished by integrating neutron and spectroscopic γ-ray detectors into a container crane spreader bar, the part of the...

To elucidate the role of the eicosanoids prostaglandin E(2) (PGE(2)), 6-keto-prostaglandin F(1a) (PGF(1a)) and thromboxane B(2) (TXB(2)) in the maintenance of two-kidney, one-clip renovascular hypertension in rats. The right renal artery was constricted by a silver clip in 63 male Sprague-Dawley rats to induce hypertension, while a sham operation w...

To evaluate effectiveness and safety of intracorporeal holmium:YAG (Ho:YAG) laser lithotripsy of ureteral calculi. Between October 2003 and September 2005, 45 patients (age range 27-74, mean age 51.5 years) with 49 ureteral stones (measuring 4-28 mm in size) were treated with Ho:YAG laser lithotripsy. The locations of the stones in the ureter were:...

Compact, high performance X-ray and gamma-ray spectroscopy systems are required for many applications, both in the field and in the laboratory. The X-123 provides this by combining Amptek's thermoelectrically cooled X-ray and gamma-ray detectors and Amptek's digital signal processing technology with a compact, high efficiency power supply in a smal...

This paper describes the development of a field portable gamma-ray spectroscopy system based on multielement CdTe detectors. A stack of multiple planar detector elements is used, with each individual element thin enough for good charge transport but with the outputs summed so that the full volume is used. The detector elements are CdTe diodes mount...

The in-situ X-ray fluorescence analysis (XRF) of ancient artifacts from the excavation area of Akrotiri, Greece was performed using novel instrumentation composed of a portable silicon PIN thermoelectrically cooled X-ray detector, a miniature X-ray source, and portable data acquisition devices. The main objective of the analyses was to explore the...