14164208
A prototype liquid Argon Time Projection Chamber for the study of UV laser multi-photonic ionization
This paper describes the design, realization and operation of a prototype liquid Argon Time Projection Chamber (LAr TPC) detector dedicated to the development of a novel online monitoring and calibration system exploiting UV laser beams. In particular, the system is intended to measure the lifetime of the primary ionization in LAr, in turn related to the LAr purity level. This technique could be exploited by present and next generation large mass LAr TPCs for which monitoring of the performance and calibration play an important role. Results from the first measurements are presented together with some considerations and outlook.
98478755
Monitoring the parameters of a large size liquid Argon Time Projection Chamber using UV laser beams
This paper reports on multiphoton ionization at 266 nm of liquid Argon in a Time Projection Chamber (LAr TPC) detector. The electron signal produced by the laser beam is a formidable tool for the monitoring of the next generation large mass LAr TPCs [1]. The detector we have designed and tested allowed us also to measure the two-photon absorption cross-section (σex) of LAr with unprecedented accuracy and precision, appropriate for using the UV laser technique also for a quantitative calibration of the detector.
122078935
The LAGUNA project: Towards the giant liquid based detectors for proton decay searches and for low energy neutrino astrophysics
Jan Kisiel Institute of Physics, University of Silesia Uniwersytecka 4, 40-007 Katowice, Poland E-mail: Jan.Kisiel@us.edu.pl D. Angusa, A. Arigab, D. Autieroc, A. Apostud, A. Badertschere, T. Bennetf, G. Bertolag, P.F. Bertolag, O. Besidah, A. Bettinii, C. Boothf, J.L. Bornec, I. Brancusd, W. Bujakowskij, J.E. Campagnec, G. Cata-Danild, F. Chipesiud, M. Chorowskik, J. Crippsf, A. Curionie, S. Davidsonc, Y.R.A Declaisc, U. Drostg, O. Duliul, J. Dumarchezc, T. Enqvistm, A. Ereditatob, F. v Feilitzschn, H. Fynboo, T. Gamblef, G. Galvaninp, A. Gendottie, W. Gizickik, M. GogerNeffn, U. Grassling, D. Gurneyq, M. Hakalar, S. Hannestado, M. Haworthq, A. Jipal, F. Jugetb, T. Kalliokoskis, S. Katsanevasc, M. Keent, I.Kreslob, V. Kudryastevf, P. Kuusiniemim, L. Labargau, T. Lachenmaiern, J.C. Lanfranchin, I. Lazanul, T. Lewken, K. Loom, P. Lightfootf, M. Lindnerv, P. Lombardiw, A. Longhinh, J. Maalampis, M. Marafinic, A. Marchionnie, R.M. Margineanud, A. Markiewiczx, T. Marrodan-Undagoitan, J.E. Marteauc, R. Matikainenr, Q. Meindln, M. Messinab, J.W. Mietelskiy, B. Mitricad, A. Mordasinig, L. Moscah, U. Moserb, G. Nuijtenr, L. Oberauern, A. Oprinad, S. Palingf, S. Pascolia, T. Patzakc, M. Pectud, Z. Pileckij, F. Piquemalc, W. Potzeln, W. Pytelx, M. Raczynskix, G. Raffeltz, G. Ranucciw, G. Ristainop, M. Robinsonf, R. Rogersq, J. Roinistor, M. Romanai, E. RondioA, B. Rossib, A. Rubbiae, Z. Sadeckix, C. Saenzi, A. Saftoiud, J. Salmelainenr, O. Simal, J. Slizowskij, K. Slizowskij, J. SobczykB, N. Spoonerf, S. Stoicad, J. Suhonens, R. SulejA, M. Szarskay, T. SzeglowskiC, M. Temussip, J. Thompsonq, L. Thompsonf, W.H. Trzaskas, M. Tippmannn, A. Tonazzoc, K. Urbanczykj, G. Vasseurh, A. Williamst, J. Wintern, K. Wojtuszewskaj, M. Wurmn, A. Zalewskay, M. Zampaoloc, M. Zitoh
118548096
Measurement of the two-photon absorption cross-section of liquid argon with a time projection chamber
This paper reports on laser-induced multiphoton ionization at 266?nm of liquid argon in a time projection chamber (LAr TPC) detector. The electron signal produced by the laser beam is a formidable tool for the calibration and monitoring of next-generation large-mass LAr TPCs. The detector that we designed and tested allowed us to measure the two-photon absorption cross-section of LAr with unprecedented accuracy and precision: ?ex=(1.24?0.10stat?0.30syst)?10? 56?cm4?s? 1.
52244461
Design and operation of ARGONTUBE: a 5 m long drift liquid argon TPC
The Liquid Argon Time Projection Chamber (LArTPC) is a prime type of detector for future large-mass neutrino observatories and proton decay searches. In this paper we present the design and operation, as well as experimental results from ARGONTUBE, a LArTPC being operated at the AEC-LHEP, University of Bern. The main goal of this detector is to prove the feasibility of charge drift over very long distances in liquid argon. Many other aspects of the LArTPC technology are also investigated, such as a voltage multiplier to generate high voltage in liquid argon (Greinacher circuit), a cryogenic purification system and the application of multi-photon ionization of liquid argon by a UV laser. For the first time, tracks induced by cosmic muons and UV laser beam pulses have been observed and studied at drift distances of up to 5 m, the longest reached to date.
119265780
Ionization signals from electrons and alpha-particles in mixtures of liquid Argon and Nitrogen – perspectives on protons for Gamma Resonant Nuclear Absorption applications
In this paper we report on a detailed study of ionization signals produced by Compton electrons and alpha-particles in a Time Projection Chamber (TPC) filled with different mixtures of liquid Argon and Nitrogen. The measurements were carried out with Nitrogen concentrations up to 15% and a drift electric field in the range 0-50 kV/cm. A prediction for proton ionization signals is made by means of interpolation. This study has been conducted in view of the possible use of liquid Ar−N2 TPCs for the detection of gamma-rays in the resonant band of the Nitrogen absorption spectrum, a promising technology for security and medical applications.
120635227
Cosmic-Ray Theory
122227593
Evidence for x Rays From Sources Outside the Solar System
Data from an Aerobee rocket carrying three large-area geiger counters have revealed a considerable flux of radiation in the night sky. Analysis of these data indicates the bulk of the radiation is soft x rays from sources outside the solar system. Synchrotron radiation by cosmic electrons is a possible mechanism for the production of these x rays. Ordinary stellar sources could also contribute a considerable fraction of the observed radiation. (H.D.R.)
119999230
Early days in cosmic rays
Early in 1928, shortly after receiving my PhD at the University of Bologna, I was offered the position of assistant at the Physics Institute of the University of Florence. The Institute rose among olive trees, on the hill of Arcetri, a short distance from the villa where Galileo had spent the last years of his life as a political exile. The chair of physics was held by Professor Antonio Garbasso who, in earlier years, had done some creditable scientific work. But the first world war and subsequent events had diverted his interests toward politics. He was now a senator and the mayor of Florence. However, he still went to Arcetri three times a week to deliver his lectures, and he still had a strong desire to see the Institute, which he had built, become an important center of research.
122928206
ISOTROPY OF COSMIC RADIATION
Cosmic radiation data obtained at the Mass. Inst. of Tech. Volcano Ranch station in 1960 to 1961 were compared with that taken in 1959 to 1960 at the same location. The 1960 to 1961 data were obtained after the area of the array was increased by a factor of four and therefore have 3 times the statistical weight of the 1959 to 1960 data. An isotropic distribution in the direction of arrival of primary particles at about 10/sup 18/ ev is indicated. No conclusive evidence for existence or non-existence of anisotropies was found. (L.N.N.)
124758213
The Variation of the Hard Component of Cosmic Rays With Height and the Disintegration of Mesotrons