This study aims at the experimental determination of the detector-specific 1D lateral dose response function K(x) and of its associated rotational symmetric counterpart K(r) for a set of high-resolution detectors presently used in narrow-beam photon dosimetry. A combination of slit-beam, radiochromic film, and deconvolution techniques served to accomplish this task for four detectors with diame...

Background: High level radiation areas have been recognized on various parts of the earth. Mahallat hot spring region is one of these areas. Study of exposure in these areas can be helpful in investigating the effects of ionizing radiation. Internal and external exposure to the staff was studied. Materials and Methods: Used materials and instruments include: RSS-112 ionizing chamber fo...

Abstract Radon is the main background source of dark matter and neutrino experiments. concentration (mBq/m 3 ) measurement by liquid scintillation detector a highly sensitive method at low temperatures using silicon photomultipliers (SiPMs) arrays. The SiPM performance characteristics are closely related to lower detection limit detector. In this study, we built an automatic accurate low-temper...

A flux of weakly interacting neutral particles incident on the Earth would produce occasional nuclear-recoil events in any material. These could be detected as scintillation or ionization pulses in suitable target materials. Expected rates are in the range 1-10(-4) events kg(-1) d(-1). These must be distinguished from much higher rates due to backgrounds from gamma and beta background, even in ...

Department of Radiology, Stanford University, Stanford, CA 94305, USA The aim of this work is to demonstrate time of flight (ToF) performance from analog electro-optical transmission of SiPM-based PET detector signals. In electro-optical readout schemes, scintillation signals are converted to near-infrared light by a laser diode and transmitted out of the MRI bore with fiber-optics [1], greatly...

A miniature scintillation detector recently designed and constructed in this laboratory can be inserted into the esophagus and under fluoroscopic vision positioned so that radioactivity emitted from the blood in the descending aorta can be detected and a time-concentration curve recorded from which cardiac output can be determined. Twenty simultaneous determinations of cardiac output by the iso...

We present details of the technical design and manufacture of the ZEPLIN-III dark matter experiment. ZEPLIN-III is a two-phase xenon detector which measures both the scintillation light and the ionisation charge generated in the liquid by interacting particles and radiation. The instrument design is driven by both the physics requirements and by the technology requirements surrounding the use o...

While developing a liquid argon detector for dark matter searches we investigate the influence of air contamination on the VUV scintillation yield in gaseous argon at atmospheric pressure. We determine with a radioactive αsource the photon yield for various partial air pressures and different reflectors and wavelength shifters. We find for the fast scintillation component a time constant τ1 = 1...

The single-hole collimator limits the field of view of a scintillation probe to a single organ. The sensitivity for counting is approximately equal over the entire field of view. The most common use of this collimator is for iodine uptake measurements of the thyroid. An example of this "flat-field collimator" is shown (Fig. I). The sensitivity profile at the working distance illustrates the rel...

The Cryogenic Rare Event Search with Superconducting Thermometers Phase II (CRESST-II) at the L.N.G.S in Italy is searching for Dark Matter using low-temperature calorimeters. These detectors allow to discriminate di erent particles by simultaneous measurement of phonons and scintillation light. The sensors used consist of superconducting tungsten thinlm thermometers, which measure the thermal ...