66 research outputs found
Radiation protection at CERN
This paper gives a brief overview of the general principles of radiation
protection legislation; explains radiological quantities and units, including
some basic facts about radioactivity and the biological effects of radiation;
and gives an overview of the classification of radiological areas at CERN,
radiation fields at high-energy accelerators, and the radiation monitoring
system used at CERN. A short section addresses the ALARA approach used at CERN.Comment: 22 pages, contribution to the CAS - CERN Accelerator School: Course
on High Power Hadron Machines; 24 May - 2 Jun 2011, Bilbao, Spai
Traceable measurements of the activity concentration in air
The nuclear reactions induced by high energetic protons in heavy targets such as UC/sub 2/ and ThC cause a particular, complex radiation protection task at facilities like ISOLDE: the measurement of a mixture of different isotopes of the radioactive noble gas radon and the radon progenies in air. The knowledge of their respective activity concentration is fundamental for exposure assessments. Due to the complex mixture of activity concentrations in air, its precise determination is quite difficult. Therefore, a new procedure for taking reference samples was developed and implemented for the traceable measurement of the activity concentration of radioactive ions (e.g., radon progenies) in air. This technique is combined by measuring alpha -particles with a multi-wire ionization chamber for the parallel on-line determination of the activity concentration of different radon isotopes. (10 refs)
A Second Generation Radioactive Nuclear Beam Facility at CERN
The proposed Superconducting Proton Linac (SPL) at CERN would be an ideal driver for a proton-driven second-generation Radioactive Nuclear Beam facility. We propose to investigate the feasibility of constructing such a facility at CERN close to the present PS Booster ISOLDE facility. The existing ISOLDE facility would be fed with a 10 micro-amps proton beam from SPL, providing the physics community with a low-intensity experimental area. A second, new facility would be built with target stations deep underground, permitting proton beam intensities of more than 100 micro-amps. The secondary beams can be post-accelerated to 20-100 MeV/u and there will be a storage ring complex and large segmented detectors in the experimental area. Also, benefits from a muon-ion collider or from merging the ions and muons should be investigated. Since the antiproton decelerator would be nearby, the opportunities for antiprotonic radioactive atom studies should be pursued as well
Measurements of spectroscopic quadrupole moments of neutron-deficient Ir isotopes and shape coexistence in Ir
Measurements of the electric quadrupole moment of Nb and Zr isotopes with modulated adiabatic fast passage after recoil implantation into hcp Co
First PAC studies on the hydrogen diffusion in III-V semiconductors
We report on first experiments which observe on a microscopic scale the migration of isolated hydrogen in InP, InAs and GaAs. Using the radioactive acceptor 117Cd, Cd-H pairs have been formed in these III-V semiconductors. After the decay of 117Cd to 117In, H is no longer bound to 117In and can diffuse freely. This diffusion has been observed by perturbed gg angular correlation (PAC) spectroscopy. At 10 K, the occupation of two different lattice sites by hydrogen has been observed
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