Characterization of polycrystalline Cu(In,Ga)Te2 thin films prepared by pulsed laser deposition

Thin films of the chalcopyrite compound CuGaXIn1-XTe2 (0=<X=<1) have been prepared by pulsed laser deposition (PLD) of prereacted material onto glass substrates. The structural and optical properties of these films have been investigated using the techniques of X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), Rutherford back scattering (RBS), transmittance (T), reflectance (R). Electrical characterization was performed using Hall and resistivity measurements, using the Van der Pauw technique at 300 K. The composition of the laser-deposited films was found to closely match that of the target materials and the XRD showed them to be single phase with the chalcopyrite structure and a preferred orientation along the (112) plane. The spectral dependence of the refractive index n and absorption coefficient alpha of the Cu(In,Ga)Te2 thin films were determined using rigorous expressions for transmission and reflection in an air/film/substrate/air multilayer system. The CuGaXIn1-XTe2 films had optical absorption coefficients of order 104 cm-1 and the energy gaps observed in these films increased from 0.96 to 1.32 eV with increasing Ga content

CNGS beam monitor with the LVD detector

The importance of an adequate CNGS beam monitor at the Gran Sasso Laboratory has been stressed in many papers. Since the number of internal v(mu) CC and NC interactions in the various detectors will not allow to collect statistics rapidly, one should also be able to detect the v(mu) CC interactions in the upstream rock. In this study, we have investigated the performances of the LVD detector as a monitor for the CNGS neutrino beam. Thanks to its wide area (13 x 11 m(2) orthogonal to the beam direction) LVD can detect about 120 muons per day originated by v(mu) CC interactions in the rock. The LVD total mass is similar to2 kt. This allows to get 30 more CNGS events per day as internal (NC + CC) v(mu) interactions, for a total of similar to150 events/day. A 3% statistical error can be reached in 7 days. Taking into account the time characteristics of the CNGS beam, the cosmic muon background can be reduced to a negligible level, of the order of 1.5 events/day. (C) 2003 Elsevier B.V. All rights reserved.51619610

The high energy muon spectrum in Extensive Air Showers: first data from LVD and EAS-TOP at Gran Sasso

We present evidence for a dependence of the average deep underground muon energies on shower size in the coincident EAS-TOP and LVD data at the Gran Sasso laboratories. The measured relation agrees with a mixed chemical composition of the cosmic ray primary spectrum at energies around 10(15) eV. (C) 1998 Elsevier Science B.V.9318519

SINGLE MUONS IN THE LARGE-VOLUME DETECTOR

The first angular distribution data from 5547 hours of operation of the LVD detector are presented. A total of 452,630 single muons were reconstructed for this period. We present, for the first time from Gran Sasso Laboratory, data at near-horizontal zenith angles.3524024

SEARCH FOR NEUTRINOS FROM COLLAPSING STARS WITH THE LVD AT GRAN-SASSO

The Large Volume Detector (LVD) in the Gran Sasso underground Laboratory is a multipurpose detector consisting of a large volume of liquid scintillator interleaved with limited streamer tubes. In this paper we discuss its power to study low energy cosmic neutrinos. The results show that the first of the five LVD towers, operational since June 1992 with 368 tons of liquid scintillator, is well suited to detect neutrinos from collapsing stars within all our Galaxy, over a wide range of burst duration (up to a few hundreds seconds). One year data, collected since June 1992, have been analized and results are here discussed. No evidence for burst candidates has been found in this period of data taking.3526726

MULTIPLE MUON EVENTS OBSERVED IN THE LVD EXPERIMENT

This is a progress report on the multiple muon events recorded by the first tower of the LVD detector at the Gran Sasso Laboratory. About 17,000 multiple muon events have been observed since the LVD first tower started operation in June 1992. Presented here are the measured multiplicity distribution and separation distribution of muon pairs in the bundles.3524324

Single muon angular distributions observed in the LVD particle astrophysics experiment

The first angular distribution data from 5547 hours of operation of the LVD detector are presented. The technique of track reconstruction is described. A total of 452 657 single muons were reconstructed for this period. The data are acceptance corrected in our final plots. The total single muon flux (the total flux from above impinging on a sphere of unit cross sectional area) in the Gran Sasso Laboratory is 1.03 muons per hour per square meter. The total flux crossing a unit horizontal area from above is 0.79 muons per hour per square meter. The acceptance-corrected intensity at cos theta = 1 is 0.349 muons per hour per square meter per steradian (9.7 x 10(-9) muons per second per square centimeter per steradian). We present, for the first time from Gran Sasso Laboratory, data at near-horizontal zenith angles.22103116Italian Institute for Nuclear Physics (INFN)US Department of EnergyUS National Science FoundationState of Texas under its TATRP progra