stable isotopes of carbon, hydrogen, and nitrogen offer a number of advantages in clinical work: problems of preparation, storage, and disposal are negligible, health monitoring requirements are eliminated, and most significantly, the absence of radiochemical hazard to the patient permits their use in obstetric and pediatric measurements. It is our belief that the potential of stable isotope an...

The XENON experiment aims at the direct detection of dark matter in the form of WIMPs (Weakly Interacting Massive Particles) via their elastic scattering off Xe nuclei. A fiducial mass of 1000 kg, distributed in ten independent liquid xenon time projection chambers(LXeTPCs) will be used to probe the lowest interaction cross section predicted by SUSY models. The TPCs are operated in dual (liquid...

A dedicated test of the effects of Nitrogen contamination in liquid Argon has been performed at the INFN-Gran Sasso Laboratory (LNGS, Italy) within the WArP R&D program. A detector has been designed and assembled for this specific task and connected to a system for the injection of controlled amounts of gaseous Nitrogen into the liquid Argon. Purpose of the test is to detect the reduction of th...

The XENON experiment aims at the direct detection of dark matter in the form of WIMPs (Weakly Interacting Massive Particles) via their elastic scattering off Xenon nuclei. With a fiducial mass of 1000 kg of liquid xenon, a sufficiently low threshold of 16 keV recoil energy and an unrejected background rate of 10 events per year, XENON would be sensitive to a WIMP-nucleon interaction cross secti...

INTRODUCTION Low-level radioactive waste is the primary component of the toxic waste stream generated from biomedical research and patient care activities. Historically, this radioactive waste has been shipped to Richland, Washington for landfill disposal. Several years ago, the Nuclear Regulatory Commission "deregulated" liquid scintillation vials containing tritium and carbon 14. More recentl...

A liquid scintillation counter with an active volume 3.05 m x 0.20 m x 0.20 m was constructed with a simple, inexpensive, and rugged design. Some properties of this counter are reported .

Abstract We present several novel ionization-electron and scintillation-photon recording concepts in noble-liquid detectors, for future applications particle astroparticle physics other fields. These involve both single- dual-phase detector configurations with combined electroluminescence small charge multiplication gas liquid media.

The aim of the study was to measure the carbon 14 activity at natural level in air samples using classical methods of radiochemistry and beta counting. Three different methods have been tested in order to minimise the detection limit. In the three methods, the first step consists in trapping the atmospheric carbon 14 into NaOH (1N) using a bubbling chamber. The atmospheric carbon dioxide reacts...

We present a method for the measurement of hydrogenase (H(2)ase) activity in aquatic sediments. The assay is based on the H(2)ase-mediated isotopic exchange between dissolved molecular hydrogen (H(2)) and water. A slurry of sediment material is incubated with a tritiated hydrogen (HT) headspace in a glass syringe on a rotary shaker. The method includes a procedure for preparing HT from radiolab...

Uptake of (14)CO(2) in soils due to algae or sulfur-oxidizing bacteria was examined by incubation of soil samples with gaseous (14)CO(2) and subsequent chemical oxidation of biologically fixed radioactive isotope to (14)CO(2) for detection with a liquid scintillation counting system. The (14)CO(2) was added to the soil in the gas phase so that no alteration of the moisture or ionic strength of ...