Search results for " Simulation"

Dosimetry for electron Intra-Operative RadioTherapy: Comparison of output factors obtained through alanine/EPR pellets, ionization chamber and Monte …

2015

Abstract In this work a comparison between the response of alanine and Markus ionization chamber was carried out for measurements of the output factors (OF) of electron beams produced by a linear accelerator used for Intra-Operative Radiation Therapy (IORT). Output factors (OF) for conventional high-energy electron beams are normally measured using ionization chamber according to international dosimetry protocols. However, the electron beams used in IORT have characteristics of dose per pulse, energy spectrum and angular distribution quite different from beams usually used in external radiotherapy, so the direct application of international dosimetry protocols may introduce additional uncer…

A pulsed high-voltage decelerator system to deliver low-energy antiprotons

2021

International audience; The GBAR (Gravitational Behavior of Antihydrogen at Rest) experiment at CERN requires efficient deceleration of 100 keV antiprotons provided by the new ELENA synchrotron ring to synthesize antihydrogen. This is accomplished using electrostatic deceleration optics and a drift tube that is designed to switch from -99 kV to ground when the antiproton bunch is inside – essentially a charged particle “elevator” – producing a 1 keV pulse. We describe the simulation, design, construction and successful testing of the decelerator device at -92 kV on-line with antiprotons from ELENA.

Computational and experimental studies of the flow field near the beam entrance window of a liquid metal target

2014

Abstract After the first world liquid metal target has been successfully operated at the SINQ facility at the Paul Scherrer Institut (PSI) for 6 months. The idea of having a reliable target with a bypass flow for cooling the beam entrance window, but with the bypass flow not driven by a separate pump, was examined within the project called LIMETS (Liquid Metal Target for SINQ). In designing of liquid metal targets, turbulence modelling is of high importance due to lack in methods for measuring the spatial distribution of flow and turbulence characteristics. In this study, validation of different turbulence models were performed in water model with hemispherical geometry using particle image…

Multiplicity fluctuations in hadronic final states from the decay of the Z0

1992

An analysis of the fluctuations in the phase space distribution of hadrons produced in the decay of 78829 Z0 has been carried out, using the method of factorial moments. The high statistics collected by the DELPHI experiment at LEP during 1990 allowed studies of the event sample both globally and in intervals of p(t) and multiplicity, and for different jet topologies and for single jets. A large contribution to the factorial moments of the one-dimensional data on rapidity with respect to the event axis comes from hard gluons. Details of factorial moments in two and three dimensions are presented. Influences of resonance decays have been studied by Monte Carlo simulation: one-dimensional fac…

Interaction position resolution simulations and in-beam measurements of the AGATA HPGe detectors

2011

WOS: 000290082600015

Monte Carlo simulation of a single detector unit for the neutron detector array NEDA

2012

WOS: 000301813500009

Mixture and dissolution of laser polarized noble gases: Spectroscopic and imaging applications

2012

A Model to Characterize the D-T Layer of ICF Targets by Backlit Optical Shadowgraphy

2005

A numerical model is presented in order to modelize the bright ring that appears in backlit optical shadowgraphy on a transparent hollow sphere with a solid deuterium-tritium layer inside. This novel model is based on computational calculations applied to the problem of the targets used in inertial confinement fusion. The model takes into account the influences of the optical imaging system (numerical aperture, source divergence, camera resolution, etc.) and the effect of the capsule itself, diameter, thickness, and refractive index, and allows one to analyze the inner surface of a capsule in terms of thickness and roughness.

Enhancing the extraction of laser-ionized beams from an arc discharge ion source volume

2018

© 2018 The Author(s) The Versatile Arc Discharge and Laser Ion Source (VADLIS) is a recently established ion source for the CERN-ISOLDE radioactive ion beam facility. It offers either electron-impact ionization (VADIS-mode) or resonance laser ionization (RILIS-mode). The choice of operating mode depends on the element of interest or the required beam purity. Particle-in-cell simulations using the VSim software show that the ion extraction efficiency of the VADLIS in RILIS-mode can be improved if it is equipped with an insulated extractor plate, to which an optimal voltage can be applied. This enables optimization of the RILIS-mode ion extraction independently of the electron density. Experi…

Single-Event Burnout Mechanisms in SiC Power MOSFETs

2018

Heavy ion-induced single-event burnout (SEB) is investigated in high-voltage silicon carbide power MOSFETs. Experimental data for 1200-V SiC power MOSFETs show a significant decrease in SEB onset voltage for particle linear energy transfers greater than 10 MeV/cm 2 /mg, above which the SEB threshold voltage is nearly constant at half of the rated maximum operating voltage for these devices. TCAD simulations show a parasitic bipolar junction transistor turn-on mechanism, which drives the avalanching of carriers and leads to runaway drain current, resulting in SEB. peerReviewed