133 research outputs found
SPIRAL 2 injector diagnostics
International audienceThe future SPIRAL2 facility will be composed of a multi-beam driver accelerator (5 mA/40 MeV deuterons, 5 mA /14.5 MeV/u heavy ions) and a dedicated building for the production of radioactive ion beams (RIBs). RIBs will be accelerated by the existing cyclotron CIME for the post acceleration and sent to GANIL's experimental areas. The injector constituted by an ion source a deuteron/proton source a L.E.B.T. and a M.E.B.T. lines and a room temperature R.F.Q. will produces, transports and accelerates beams up to an energy of 0.75 MeV/u. An Intermediate Test Bench (B.T.I.) is being built to commission the SPIRAL2 injector through the first rebuncher of the M.E.B.T. line in a first step and the last rebuncher in a second step. The B.T.I. is designed to perform a wide variety of measurements and functions and to go more deeply in the understanding of the behaviour of diagnostics under high average intensity beam operations. A superconducting LINAC equipped with two types of cavity will allow reaching 20 MeV/u for deuterons beam. This paper describes injector diagnostic developments and gives information about the current status
MESOTHELIUM PERICARDIQUE PRIMITIF SIMULANT UN KYSTE HYDATIQUE PERICARDIQUE
The mesothelioma of pericardium is a rare tumor. Its clinical presentation is polymorphous and its diagnosis is especially histological. We report a case of 63 years old women who presented, one month before, dyspnea on exertion which evolved to orthopnea, associated to atypical thoracic pain, admitted in intensive care unit for symptoms of compressive effusion. Transthoracic echocardiography was favourable of hydatid cyst of pericardium. A thoracotomy, following cardio-circulatory arrest, showed cystic tumor of pericardium invading the left auricle, mediastinal pleura and the left pulmonary hilum. Histopathologic examination confirmed the diagnosis of mesothelioma of pericardium.Le mĂ©sothĂ©lium pĂ©ricardique primitif malin est une tumeur rare. Sa prĂ©sentation clinique est polymorphe et son diagnostic est surtout histologique. Nous rapportons le cas dâune patiente ĂągĂ©e de 63 ans ayant prĂ©sentĂ©, un mois auparavant, une dyspnĂ©e dâeffort ayant Ă©voluĂ© vers lâorthopnĂ©e et associĂ©e Ă des douleurs thoraciques atypiques, a Ă©tĂ© admise au service des urgences dans un tableau de prĂ©-tamponnade. LâĂ©chocardiographie transthoracique Ă©tait en faveur dâun kyste hydatique pĂ©ricardique avec compression des cavitĂ©s cardiaques droites. Suite Ă un arrĂȘt cardio-circulatoire, une thoracotomie de sauvetage a montrĂ© une masse kystique pĂ©ricardique envahissant lâoreillette gauche, la plĂšvre mediastinale et le hile pulmonaire gauches. Lâexamen anatomopathologique Ă lâautopsie a objectivĂ© un mĂ©sothĂ©lium pĂ©ricardique primitif malin
Stopping and Radial Flow in Central 58Ni + 58Ni Collisions between 1 and 2 AGeV
The production of charged pions, protons and deuterons has been studied in
central collisions of 58Ni on 58Ni at incident beam energies of 1.06, 1.45 and
1.93 AGeV. The dependence of transverse-momentum and rapidity spectra on the
beam energy and on the centrality of the collison is presented. It is shown
that the scaling of the mean rapidity shift of protons established for AGS and
SPS energies is valid down to 1 AGeV. The degree of nuclear stopping is
discussed; the IQMD transport model reproduces the measured proton rapidity
spectra for the most central events reasonably well, but does not show any
sensitivity between the soft and the hard equation of state (EoS). A radial
flow analysis, using the midrapidity transverse-momentum spectra, delivers
freeze-out temperatures T and radial flow velocities beta_r which increase with
beam energy up to 2 AGeV; in comparison to existing data of Au on Au over a
large range of energies only beta_r shows a system size dependence
Abundance of Delta Resonances in 58Ni+58Ni Collisions between 1 and 2 AGeV
Charged pion spectra measured in 58Ni-58Ni collisions at 1.06, 1.45 and 1.93
AGeV are interpreted in terms of a thermal model including the decay of Delta
resonances. The transverse momentum spectra of pions are well reproduced by
adding the pions originating from the Delta-resonance decay to the component of
thermal pions, deduced from the high transverse momentum part of the pion
spectra. About 10 and 18% of the nucleons are excited to Delta states at
freeze-out for beam energies of 1 and 2 AGeV, respectively.Comment: 14 pages, LaTeX with 3 included figures; submitted to Physics Letters
K^+ production in the reaction at incident energies from 1 to 2 AGeV
Semi-inclusive triple differential multiplicity distributions of positively
charged kaons have been measured over a wide range in rapidity and transverse
mass for central collisions of Ni with Ni nuclei. The transverse
mass () spectra have been studied as a function of rapidity at a beam
energy 1.93 AGeV. The distributions of K^+ mesons are well described by a
single Boltzmann-type function. The spectral slopes are similar to that of the
protons indicating that rescattering plays a significant role in the
propagation of the kaon. Multiplicity densities have been obtained as a
function of rapidity by extrapolating the Boltzmann-type fits to the measured
distributions over the remaining phase space. The total K^+ meson yield has
been determined at beam energies of 1.06, 1.45, and 1.93 AGeV, and is presented
in comparison to existing data. The low total yield indicates that the K^+
meson can not be explained within a hadro-chemical equilibrium scenario,
therefore indicating that the yield does remain sensitive to effects related to
its production processes such as the equation of state of nuclear matter and/or
modifications to the K^+ dispersion relation.Comment: 24 pages Latex (elsart) 7 PS figures to be submitted to Nucl. Phys
CMS Forward-Backward MSGC milestone
The CMS MF1 milestone was set in order to evaluate system aspects of the CMS forward-backward MSGC tracker, to check the design and feasibility of mass production and to set up assembly and test procedures. We describe the construction and the experience gained with the operation of a system of 38 MSGC detectors assembled in six multi-substrate detector modules corresponding to the geometry of the forward-backward MSGC tracker in CMS. These modules were equipped with MSGCs mounted side by side, forming a continuous detector surface of about 0.2 m2. Different designs were tried for these modules. The problems encountered are presented with the proposed solutions. Operation conditions for the 38 MSGCs are reported from an exposure to a muon beam at the CERN SPS. Gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with the detection efficiency, the spatial resolution, alignment and edge studies
Progress in Diamond Detector Development
Detectors based on Chemical Vapor Deposition (CVD) diamond have been used successfully in Luminosity and Beam Condition Monitors (BCM) in the highest radiation areas of the LHC. Future experiments at CERN will accumulate an order of magnitude larger fluence. As a result, an enormous effort is underway to identify detector materials that can operate under fluences of 1 · 1016 n cmâ2 and 1 · 1017 n cmâ2. Diamond is one candidate due to its large displacement energy that enhances its radiation tolerance. Over the last 30 years the RD42 collaboration has constructed diamond detectors in CVD diamond with a planar geometry and with a 3D geometry to extend the material's radiation tolerance. The 3D cells in these detectors have a size of 50 ”mĂ50 ”m with columns of 2.6 ”m in diameter and 100 ”mĂ150 ”m with columns of 4.6 ”m in diameter. Here we present the latest beam test results from planar and 3D diamond pixel detectors
- âŠ