Search results for "accelerator physics"
showing 10 items of 1294 documents
"Table 4" of "Production of muons from heavy-flavour hadron decays in p-Pb collisions at $\mathbf{\sqrt{{\textit s}_{NN}} = 5.02}$ TeV"
2017
pT-differential nuclear modification factor of heavy-flavour decay muons at forward rapidity (proton-going side)
"Table 2" of "Production of muons from heavy-flavour hadron decays in p-Pb collisions at $\mathbf{\sqrt{{\textit s}_{NN}} = 5.02}$ TeV"
2017
pT-differential nuclear modification factor of heavy-flavour decay muons at forward rapidity (proton-going side)
"Table 6" of "Production of muons from heavy-flavour hadron decays in p-Pb collisions at $\mathbf{\sqrt{{\textit s}_{NN}} = 5.02}$ TeV"
2017
pT-differential forward-to-backward ratio of heavy-flavour decay muons
Direct measurement of resonance driving terms in the super proton synchrotron (SPS) of cern using beam position monitors
2003
El objetivo principal de esta tesis consiste en desarrollar un metodo para medir los terminos resonantes del Hamiltoniano de un acelerador mediante la transfomada de Fourier de la posicion del haz vuelta tras vuelta. Dos aspectos fundamentales de este metodo de medida son: el efecto de la decoherencia del haz en el espectro de Fourier y la variacion longitudinal de estos terminos resonantes. Ambos se estudian analiticamente y mediante simulaciones numericas. Con el fin de probar la validez de esta tecnica se realizaron experimentos en dos aceleradores de hadrones: el SPS del CERN y el RHIC del BNL. Por ultimo se estudia como utilizar dipolos AC para que esta tecnica no sea destructiva
Design study for a 500 MeV positron beam at the Mainz Microtron MAMI
2022
A design study has been performed for a positron beam with an energy of 500 MeV to be realized at the applied physics area of the Mainz Microtron MAMI. Positrons will be created after pair conversion of bremsstrahlung, produced by the 855 MeV electron beam af MAMI in a tungsten converter target. From the two conceivable geometries (i) pair conversion in the bremsstrahlung converter target itself, and (ii) bremsstrahlung pair conversion in a separated lead foil, the former was considered in detail. Positrons will be energy selected within an outside open electron beam-line bending magnet, and bent back by an additional sector magnet. Magnetic focusing elements in between are designed to prep…
Optical absorption of divalent metal tungstates: Correlation between the band-gap energy and the cation ionic radius
2008
We have carried out optical-absorption and reflectance measurements at room temperature in single crystals of AWO4 tungstates (A = Ba, Ca, Cd, Cu, Pb, Sr, and Zn). From the experimental results their band-gap energy has been determined to be 5.26 eV (BaWO4), 5.08 eV (SrWO4), 4.94 eV (CaWO4), 4.15 eV (CdWO4), 3.9-4.4 eV (ZnWO4), 3.8-4.2 eV (PbWO4), and 2.3 eV (CuWO4). The results are discussed in terms of the electronic structure of the studied tungstates. It has been found that those compounds where only the s electron states of the A2+ cation hybridize with the O 2p and W 5d states (e.g BaWO4) have larger band-gap energies than those where also p, d, and f states of the A2+ cation contribu…
Present status and first results of the final focus beam line at the KEK Accelerator Test Facility
2011
ATF2 is a final-focus test beam line which aims to focus the low emittance beam from the ATF damping ring to a vertical size of about 37 nm and to demonstrate nanometer level beam stability. Several advanced beam diagnostics and feedback tools are used. In December 2008, construction and installation were completed and beam commissioning started, supported by an international team of Asian, European, and U.S. scientists. The present status and first results are described.
New exotic beams from the SPIRAL 1 upgrade
2018
Since 2001, the SPIRAL 1 facility has been one of the pioneering facilities in ISOL techniques for reaccelerating radioactive ion beams: the fragmentation of the heavy ion beams of GANIL on graphite targets and subsequent ionization in the Nanogan ECR ion source has permitted to deliver beams of gaseous elements (He, N, O, F, Ne, Ar, Kr) to numerous experiments. Thanks to the CIME cyclotron, energies up to 20 AMeV could be obtained. In 2014, the facility was stopped to undertake a major upgrade, with the aim to extend the production capabilities of SPIRAL 1 to a number of new elements. This upgrade, which is presently under commissioning, consists in the integration of an ECR booster in the…
Fast photon detection for particle identification with COMPASS RICH-1
2006
Particle identification at high rates is an important challenge for many current and future high-energy physics experiments. The upgrade of the COMPASS RICH-1 detector requires a new technique for Cherenkov photon detection at count rates of several $10^6$ per channel in the central detector region, and a read-out system allowing for trigger rates of up to 100 kHz. To cope with these requirements, the photon detectors in the central region have been replaced with the detection system described in this paper. In the peripheral regions, the existing multi-wire proportional chambers with CsI photocathode are now read out via a new system employing APV pre-amplifiers and flash ADC chips. The ne…
Vertical Beam Polarization at MAMI
2017
For the first time a vertically polarized electron beam has been used for physics experiments at MAMI in the energy range between 180 and 855 MeV. The beam-normal single-spin asymmetry $A_{\mathrm{n}}$, which is a direct probe of higher-order photon exchange beyond the first Born approximation, has been measured in the reaction $^{12}\mathrm C(\vec e,e')^{12}\mathrm C$. Vertical polarization orientation was necessary to measure this asymmetry with the existing experimental setup. In this paper we describe the procedure to orient the electron polarization vector vertically, and the concept of determining both its magnitude and orientation with the available setup. A sophisticated method has …