Showing papers by "Arnaud Ferrari published in 2001"

FLUKA: Status and Prospects for Hadronic Applications

Abstract: The standalone FLUKA code [1] is capable of handling transport and interactions of hadronic and electromagnetic particles in any material over a wide energy range, from thermal neutrons to cosmic rays. It is intrinsecally an analogue code, but can be run in biased mode for a variety of deep penetration applications.

Predicting neutron production from cosmic ray muons

Abstract: Fast neutrons from cosmic-ray muons are an important background to underground low-energy experiments. The estimate of such a background is often hampered by the difficulty of measuring and calculating neutron production with sufficient accuracy. Indeed substantial disagreement exists between the different analytical calculations performed so far, while data reported by different experiments are not always consistent. We discuss a new unified approach to estimate the neutron yield, the energy spectrum, the multiplicity, and the angular distribution from cosmic muons using the Monte Carlo simulation package FLUKA and show that it gives a good description of most of the existing measurements once the appropriate corrections have been applied.

Calculation of the radiation environment caused by galactic cosmic rays for determining air crew exposure.

Abstract: The spectra of secondary particles resulting from interactions of primary galactic cosmic rays with the nuclei in the atmosphere have been calculated using the Monte Carlo transport code FLUKA. The simulations have been carried out at solar minimum and solar maximum activity, for several values of the vertical geomagnetic cut-off. The effective dose rate and the ambient dose equivalent rate as a function of geomagnetic cut-off and altitude have been obtained using appropriate sets of conversion coefficients. The calculated results are discussed and compared with experimental data and other calculations. A simple method is proposed to calculate the radiation exposure at aircraft altitudes.

The FLUKA radiation transport code and its use for space problems.

Abstract: FLUKA is a multiparticle transport code capable of handling hadronic and electromagnetic showers up to very high energies (100 TeV), widely used for radioprotection and detector simulation studies. The physical models embedded into FLUKA are briefly described and their capabilities demonstrated against available experimental data. The complete modelling of cosmic ray showers in the earth atmosphere with FLUKA is also described, and its relevance for benchmarking the code for space-like environments discussed. Finally, the ongoing developments of the physical models of the code are presented and discussed.

ICARUS: an innovative detector for underground physics

Abstract: The ICARUS project and in particular the construction of the 600 t module, is described. The system to detect light from liquid argon scintillation, based on photomultiplier tubes immersed in the liquid is described in some detail.

FLUKA simulations for low-energy neutron interactions and experimental validation

Abstract: The response functions of a commercial neutron detector filled with BICRON BC501A liquid scintillator are computed using the FLUKA Monte Carlo program. The simulation results are necessary to perform a direct spectroscopy by unfolding the measured proton recoil spectrum by means of the response functions of the detector using the SAND II code. The measurement of the flux intensity and of the energy distribution of a calibrated AmBe neutron source validates the method showing a good agreement with the known quantities.

Beam dynamics for the CTF3 preliminary phase

Abstract: In the framework of the CLIC RF power source studies, the new scheme of electron pulse compression and bunch frequency multiplication, using injection by RF deflectors into an isochronous ring, will be tested at CERN during the CTF3 preliminary phase. The present LPI complex will be modified in order to allow a test of this scheme at low charge. The design of the new front-end, of the modified linac, of the matched transfer line, and of the isochronous ring lattice is presented here. The results of the related beam dynamics studies are also discussed.

The ICARUS liquid argon time projection chamber

Abstract: Years of R&D allowed the overcoming of the main technological problems in the establishment of the ICARUS technology. A major step of the ICARUS scientific program has been the construction and testing of a 10 m3 prototype, which paved the way for the installation of the first 600 t ICARUS module. We present a summary of the basic principles of the ICARUS technique and some of the events collected exposing the 10 m3 module to cosmic rays at LNGS, from February to May 2000.

A method applicable to effective dose rate estimates for aircrew dosimetry.

Abstract: The inclusion of cosmic radiation as occupational exposure under ICRP Publication 60 and the European Union Council Directive 96/29/Euratom has highlighted the need to estimate the exposure of aircrew. According to a report of the Group of Experts established under the terms of Article 31 of the European Treaty, the individual estimates of dose for flights below 15 km may be done using an appropriate computer program. In order to calculate the radiation exposure at aircraft altitudes. calculations have been performed by means of the Monte Carlo transport code FLUKA. On the basis of the calculated results, a simple method is proposed for the individual evaluation of effective dose rate due to the galactic component of cosmic radiation as a function of latitude and altitude.

Monte Carlo Simulation of the Neutron Time-of-Flight Facility at CERN

Abstract: The neutron Time of Flight (n_TOF) facility at CERN is a source of neutrons produced by spallation of 20GeV/c protons onto a solid lead target The out- standing characteristics of this facility (very high intensity, 200 m flight path, wide spectral function) make it an extremely useful tool that provides the neces- sary data for the design and understanding of Accelerator Driven Systems [1-3] The proton beam is delivered by the CERN-PS [4] which is capable of providing one to four bunches with an intensity of 71012 protons per bunch, within a 144 s supercycle, at a momentum of 20 GeV/c

Nucleon decay studies in a large liquid Argon detector

Abstract: Future nuclear decay experiments have to be able to combine a large mass, the capability of distinguishing between several possible decay channels and a good background discrimination, in order to increase their sensitivity linearly with the mass. We present the capabilities of the liquid Argon technology to fulfill these requirements.

Pair production of charged Higgs bosons at future linear e+ e- colliders

Abstract: In this paper, the pair production of charged Higgs bosons at possible future e+e- linear colliders is studied. Multi-jet final states are considered and the combinatorial, hadronic and genuine tbtb backgrounds are reduced thanks to a kinematical fit. TeV-class and multi-TeV linear colliders are likely to be sensitive to charged Higgs bosons with masses up to about 350 GeV and 1.0 TeV respectively.

Studies of s-channel resonances at the CLIC multi-TeV e+e− collider

Abstract: Several models predict the existence of new resonances in the multi-TeV region, which should be accessible in e+e− collisions by s-channel production In this paper, we review the phenomenology of some specific models and we present a preliminary study of the potential of the future CLIC collider for the determination of their nature and properties

Studies of s-channel Resonances at the CLIC Multi-TeV e+e- Collider

Abstract: Several models predict the existence of new resonances in the multi-TeV region, which should be accessible in e+e- collisions by s-channel production. In this paper, we review the phenomenology of some specific models and we present a preliminary study of the potential of the future CLIC collider for the determination of their nature and properties.

Pair production of charged Higgs bosons at future linear e+e- colliders

Abstract: In this paper, the pair production of charged Higgs bosons at possible future e+e- linear colliders is studied. Multi-jet final states are considered and the combinatorial, hadronic and genuine tbtb backgrounds are reduced thanks to a kinematical fit. TeV-class and multi-TeV linear colliders are likely to be sensitive to charged Higgs bosons with masses up to about 350 GeV and 1.0 TeV respectively.

Study of the background in the measuring station at the n_TOF facility at CERN: sources and solutions

Abstract: A background roughly two orders of magnitude higher than tolerable was found in the n_TOF facility at CERN during the first measurements. This note describes a series of additional measurements performed in the n_TOF experimental area to study the origin and the characteristics of the background. The program of these measurements was determined taking into account the results from the simulations carried out by the EET group. A first phase of measurements confirmed the results of the simulations, namely that the dominant source of background was due to neutrons generated by negative muon capture. Actions to reduce the background were taken according to the results from both measurements and simulations. An iron shielding wall 3.2 m thick was then placed in between the sweeping magnet and the second collimator, with the purpose of stopping most of the muons. In a second phase of measurements, results showed that the additional shielding reduced the main component of the background by about a factor of 30.