118 research outputs found
Ground experiments for finding principles and working out methods for preventing adverse effects of weightlessness on the human organism
A comparative assessment of the effectiveness of different prophylactic procedures to prevent the adverse effects of weightlessness is presented. It is concluded that: physical training is most effective but no single method by itself produces the full effect, and an adjustment of regimes to one another enhances the effect. The approved complex of prophylactic procedures affected basic changes occurring in hypokinesia: deficit of muscular activity, no or reduced BP hydrostatic component, reduced volume of blood circulation, reduced hydration level, and the application of various prophylactic complexes during 49 day antiorthostatic hypodynamia eliminated or reduced the adverse effects of weightlessness in simulation
Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method
This paper discusses hadron energy reconstruction for the ATLAS barrel
prototype combined calorimeter (consisting of a lead-liquid argon
electromagnetic part and an iron-scintillator hadronic part) in the framework
of the non-parametrical method. The non-parametrical method utilizes only the
known ratios and the electron calibration constants and does not require
the determination of any parameters by a minimization technique. Thus, this
technique lends itself to an easy use in a first level trigger. The
reconstructed mean values of the hadron energies are within of the
true values and the fractional energy resolution is . The value of the ratio
obtained for the electromagnetic compartment of the combined calorimeter is
and agrees with the prediction that for this
electromagnetic calorimeter. Results of a study of the longitudinal hadronic
shower development are also presented. The data have been taken in the H8 beam
line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM
Construction, assembly and testing of the ATLAS hadronic end-cap calorimeter
The construction and assembly of the four wheels of the ATLAS hadronic end-cap calorimeter and their insertion into the two end-cap cryostats are described. The results of the qualification tests prior to installation of the two cryostats in the ATLAS experimental cavern are reviewed
Response of the ATLAS tile calorimeter prototype to muons
A study of high energy muons traversing the ATLAS hadron Tile calorimeter in the barrel region in the energy range between 10 and 300~GeV is presented. Both test beam experimental data and Monte Carlo simulations are given and show good agreement. The Tile calorimeter capability of detecting isolated muons over the above energy range is demonstrated. A signal to background ratio of about 10 is expected for the nominal LHC luminosity (). The photoelectron statistics effect in the muon shape response is shown. The e/mip ratio is found to be ; the e/ ratio is in the range 0.91 - 0.97. The energy loss of a muon in the calorimeter, dominated by the energy lost in the absorber, can be correlated to the energy loss in the active material. This correlation allows one to correct on an event by event basis the muon energy loss in the calorimeter and therefore reduce the low energy tails in the muon momentum distribution
Evaluation of Fermi Read-out of the ATLAS Tilecal Prototype
Prototypes of the \fermi{} system have been used to read out a prototype of the \atlas{} hadron calorimeter in a beam test at the CERN SPS. The \fermi{} read-out system, using a compressor and a 40 MHz sampling ADC, is compared to a standard charge integrating read-out by measuring the energy resolution of the calorimeter separately with the two systems on the same events. Signal processing techniques have been designed to optimize the treatment of \fermi{} data. The resulting energy resolution is better than the one obtained with the standard read-out
A measurement of the energy loss spectrum of 150 GeV muons in iron
The energy loss spectrum of 150 GeV muons has been measured with a prototype of the ATLAS hadron calorimeter in the H8 beam of the CERN SPS.\\ The differential probability per radiation length of a fractional energy loss has been measured in the range ; it is then compared with the theoretical predictions for energy losses due to bremsstrahlung and production of electron-positron pairs or of energetic knock-on electrons.\\ The integrated probability is in agreement with the theoretical predictions of and . %7.8.96 - start Agreement with theory is also found in two intervals of where production of electron-positron pairs and knock-on electrons dominates. In the region of bremsstrahlung dominance () the measured integrated probability is in agreement with the theoretical value of , obtained using Petrukhin and Shestakov's \cite{PS} description of the bremsstrahlung process. The same result is about 3.6 standard deviations (defined as the quadratic sum of statistical and systematic errors) lower than the theoretical prediction of , obtained using Tsai's \cite{TS} description of bremsstrahlung
Results from a combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter
The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300~GeV at an incident angle of about 11 is well-described by the expression \sigma/E = ((46.5 \pm 6.0)\%/\sqrt{E} +(1.2 \pm 0.3)\%) \oplus (3.2 \pm 0.4)~\mbox{GeV}/E. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied
The beam and detector of the NA62 experiment at CERN
NA62 is a fixed-target experiment at the CERN SPS dedicated to measurements of rare kaon decays. Such measurements, like the branching fraction of the K+ → π+ ν bar nu decay, have the potential to bring significant insights into new physics processes when comparison is made with precise theoretical predictions. For this purpose, innovative techniques have been developed, in particular, in the domain of low-mass tracking devices. Detector construction spanned several years from 2009 to 2014. The collaboration started detector commissioning in 2014 and will collect data until the end of 2018. The beam line and detector components are described together with their early performance obtained from 2014 and 2015 data
- …