Helium purity control by thin film gas sensors at the NA-48 experiment at CERN

The authors have implemented a system for monitoring the purity of helium for the NA-48 experiment on high-energy physics at CERN. This measurement is important for correct execution of the experiment. A set of SnO2 sensors was used to the purpose for on-line information on helium purity within the required accuracy

Operating experience with chemical sensors at the CERN NA48 experiment

Oxygen adsorption on thin film sensors provides an effective tool for real-time control of the air content in the helium vessel in NA48 experiment at CERN

Calculation of the potential for interaction of particles with complex atomic structures

We present a method for calculation of the potential and related physical quantities experienced by a particle traversing an aligned periodic complex atomic structure. Classical physics equations and the expansion of periodic functions as a Fourier series have been used for the calculation. Based on this method, we have developed the ECHARM program, which calculates one- and two-dimensional averaged physical quantities of interest along the main axes of any orthorhombic and tetragonal structure. For the case of cubic symmetry, the calculation holds for any orientation. Complex structures such as zeolites have been worked out to show the capability of the program

New laser techniques for cooling of an ion beam in a storage ring

We have developed broad-band laser sources that show a sharp edge in their spectra and are particularly suitable for “white-light” laser cooling of ions in storage rings. They allow for a very large velocity capture range by maintaining the same cooling rate of single mode lasers

White-light laser cooling of ions in a storage ring

We propose the use of a "white laser" for laser cooling of ions in a storage ring. The use of a broad-band laser provides a radiation pressure force with wide velocity capture range and high magnitude, which is promising to improve the performance of both longitudinal and indirect transverse cooling. This wide-range force could also be suitable for direct transverse cooling of low-density beams

Sub-ppm NO2 sensors based on nanosized thin films of Titanium-Tungsten oxides

We describe the preparation of thin films of Ti---WO3 obtained by means of r.f. sputtering deposition followed by a thermal oxidation. The sensing characteristics of these thin films were obtained by measuring the response towards NO2 in the interval 0.5–20 ppm and to other interfering gases like ethyl alcohol, CH4 and CO; the influence of water vapour to the response towards NO2 was also investigated. The material seems to be a promising detector of NO2for environmental monitoring