Search results for "detector"
showing 10 items of 3491 documents
Testing for new physics with low-energy anti-neutrino sources: LAMA as a case study
1998
Some electroweak models with extended neutral currents, such as those based on the $E_6$ group, lead to an increase of the $\bar{\nu}-e$ scattering cross section at energies below 100 keV. We propose to search for the heavy Z' boson contribution in an experiment with a high-activity artificial neutrino source and with a large-mass detector. We present the case for the LAMA experiment with a large NaI(Tl) detector located at the Gran Sasso underground laboratory. The neutrino flux is known to within a one percent accuracy, in contrast to the reactor case and one can reach lower neutrino energies. Both features make our proposed experiment more sensitive to extended gauge models, such as the …
Hadronic calibration of the ATLAS liquid argon end-cap calorimeter in the pseudorapidity region in beam tests
2004
Abstract A full azimuthal φ -wedge of the ATLAS liquid argon end-cap calorimeter has been exposed to beams of electrons, muons and pions in the energy range 6 GeV ⩽ E ⩽ 200 GeV at the CERN SPS. The angular region studied corresponds to the ATLAS impact position around the pseudorapidity interval 1.6 | η | 1.8 . The beam test setup is described. A detailed study of the performance is given as well as the related intercalibration constants obtained. Following the ATLAS hadronic calibration proposal, a first study of the hadron calibration using a weighting ansatz is presented. The results are compared to predictions from Monte Carlo simulations, based on GEANT 3 and GEANT 4 models.
GEM-TPC-ilmaisimen testimittausten datan analyysi
2017
GEM-TPC-ilmaisin on kaasutäytteinen hiukkasilmaisin, jolla pystytään mittaaamaan hyvin pieniä sähköisiä signaaleja ja niiden syntypaikkaa ilmaisimessa. Näitä ilmaisimia tullaan tulevaisuudessa käyttämään mm. FAIRtutkimuslaitoksen Super-FRS-nimisessä fragmenttiseparaattorissa. Tässä tutkielmassa analysoin kesällä 2016 GEM-TPC:llä GSI:ssä suoritettuja ilmaisintestimittauksia ROOT-ohjelmiston avulla. Alkuun kerron, miksi GEM-TPC-ilmaisin on lähdetty suunnittelemaan, minkälaisia mittauksia ja missä sillä on tarkoitus tehdä. Tutkielman loppupuolella analysoin testimittausten tuloksia. GSI:ssä GEM-TPC:tä testattiin Xe- ja C-suihkujen avulla. Tässä tutkielmassa perehdyn syvemmin C-suihkusta tehtyi…
Test of the electric charge conservation law with Borexino detector
2015
International audience; The new limit on the electron lifetime is obtained from data of the Borexino experiment. The expected signal from the e → γν decay mode is a 256 keV photon detected in liquid scintillator. Because of the extremely low radioactive background level in the Borexino detector it was possible to improve the previous measurement by two orders of magnitude.
Scaler mode technique for the ARGO-YBJ detector
2008
The ARGO-YBJ experiment has been designed to study the Extensive Air Showers with an energy threshold lower than that of the existing arrays by exploiting the high altitude location(4300 m a.s.l. in Tibet, P.R. China) and the full ground plane coverage. The lower energy limit of the detector (E $\sim$ 1 GeV) is reached by the scaler mode technique, i.e. recording the counting rate at fixed time intervals. At these energies, transient signals due to local (e.g. Forbush Decreases) and cosmological (e.g. Gamma Ray Bursts) phenomena are expected as a significant variation of the counting rate compared to the background. In this paper the performance of the ARGO-YBJ detector operating in scaler …
Equivalent detector models for the simulation of efficiency response of an HPGe detector with PENELOPE code
2019
Monte Carlo simulation of response of an HPGe detector is a widely used technique to evaluate counting efficiencies. It is particularly useful when calibration standards with the same shape and composition of the sample under examination are not available. The result of the simulation depends on the more or less detailed knowledge of the characteristics of the detector, able to define a "model" of the same detector. To highlight parts not well defined in the manufacturer's certification, a detector X-ray analysis is usually performed, except in cases when it is not possible to dismantle the shielding structure with the loss of previous calibration data. In this work, in absence of some data…
Spatial Diagnostics of Hg/Ar and Hg/Xe Discharge Lamps by Means of Tomography
2011
In this work, the diagnostics using tomography in Hg/Xe and Hg/Ar capillary lamps is presented. First, the imaging of the lamps was performed using selected emission lines of mercury, argon and xenon in different operation conditions. Thus the tomographic reconstruction was made, to determine the spatial distribution of the emitting Hg and rare gas atoms. Significant differences of the distribution of the emitting atoms have been found in vertical and horizontal operation positions. The emitting mercury atoms in the state 73S1 were differently distributed within the lamp in the vertical and horizontal lamp positions. The radial profile has demonstrated a substantial depletion of the popula…
Imaging of Gastrointestinal Stromal Tumors: From Diagnosis to Evaluation of Therapeutic Response
2016
Once considered an obscure tumor entity with poor prognosis, gastrointestinal stromal tumors (GISTs) are nowadays recognized as the most common mesenchymal tumors of the alimentary tract. GISTs differ from other mesenchymal neoplasms at pathology since 90% of them exhibit strong immunohistochemical staining for KIT, a tyrosinase kinase growth factor receptor. In the early 2000s, the ability of imatinib mesylate, a tyrosine kinase inhibitor, to inhibit KIT established a new paradigm for cancer treatment. A reduction in lesion size may not be observed or may appear many months after therapy; thus, tumor response criteria alternative to the Response Evaluation Criteria in Solid Tumors were dev…
Determining the efficiency of optical sources using a smartphone's ambient light sensor
2017
This work reports the use of a smartphone’s ambient light sensor as a valuable tool to study and characterize the efficiency of an optical source. Here, we have measured both luminous efficacy and efficiency of several optical sources (incandescent bulb and halogen lamp) as a function of the electric power consumed and the distance to the optical detector. The illuminance of LEDs as a function of the distance to the optical detector is characterized for different wavelength emissions. Analysis of the results confirms an inverse-square law of the illuminance with the detector–source distance and shows good agreement with values obtained by classical experiments. This experience will trigger …
First search for dyons with the full MoEDAL trapping detector in 13 TeV pp collisions
2021
The MoEDAL trapping detector, consists of approximately 800 kg of aluminium volumes. It was exposed during Run-2 of the LHC program to 6.46 fb^-1 of 13 TeV proton-proton collisions at the LHCb interaction point. Evidence for dyons (particles with electric and magnetic charge) captured in the trapping detector was sought by passing the aluminium volumes comprising the detector through a SQUID magnetometer. The presence of a trapped dyon would be signalled by a persistent current induced in the SQUID magnetometer. On the basis of a Drell-Yan production model, we exclude dyons with a magnetic charge ranging up to 5 Dirac charges, and an electric charge up to 200 times the fundamental electric …