226 research outputs found
Photoemission yield and the electron escape depth determination in metal-oxide-semiconductor structures on N+-type and P+-type silicon substrates
This article gives a quantitative analysis of electron photoemission yield from N+-type and P+-type substrates of MOS structures. Based on this analysis, a method is presented to estimate both the scattering length, l, of electrons in the image force potential well and of photoelectron escape depth, x(esc), from the semiconductor substrate. This method was used to estimate the scattering length and the escape depth from the substrates of Al-SiO2-Si (N+-type and P+-type) structures. It was found that for N+-type substrate structures the scattering in the image force potential well has a dominating influence on the photoemission yield while for P+-type substrate structures both the scattering in the image force potential well and the photoemission from the subsurface regions of the photoemitter play important roles. It was found that the scattering length in the image force potential well was equal to l = 6.7-6.9 nm for structures on both N+ and P+ substrates, produced in the same processing conditions. For structures on P+ substrates, the escape depth was found to be equal to x(esc) = 8-9 nm. The scattering length, l, determined in this study is considerably larger than the one reported previously (l = 3.4 nm) for similar MOS structures. The escape depth x(esc) determined in this study is also considerably larger than the escape depth determined previously (x(esc) = 1.2-2.5 nm) for the external photoemission from uncovered silicon surfaces into vacuum
Underground operation of the ICARUS T600 LAr-TPC: first results
Open questions are still present in fundamental Physics and Cosmology, like
the nature of Dark Matter, the matter-antimatter asymmetry and the validity of
the particle interaction Standard Model. Addressing these questions requires a
new generation of massive particle detectors exploring the subatomic and
astrophysical worlds. ICARUS T600 is the first large mass (760 ton) example of
a novel detector generation able to combine the imaging capabilities of the old
famous "bubble chamber" with an excellent energy measurement in huge electronic
detectors. ICARUS T600 now operates at the Gran Sasso underground laboratory,
studying cosmic rays, neutrino oscillation and proton decay. Physical
potentialities of this novel telescope are presented through few examples of
neutrino interactions reconstructed with unprecedented details. Detector design
and early operation are also reported.Comment: 14 pages, 8 figures, 2 tables. Submitted to Jins
First results on light readout from the 1-ton ArDM liquid argon detector for dark matter searches
ArDM-1t is the prototype for a next generation WIMP detector measuring both
the scintillation light and the ionization charge from nuclear recoils in a
1-ton liquid argon target. The goal is to reach a minimum recoil energy of
30\,keVr to detect recoiling nuclei. In this paper we describe the experimental
concept and present results on the light detection system, tested for the first
time in ArDM on the surface at CERN. With a preliminary and incomplete set of
PMTs, the light yield at zero electric field is found to be between 0.3-0.5
phe/keVee depending on the position within the detector volume, confirming our
expectations based on smaller detector setups.Comment: 14 pages, 10 figures, v2 accepted for publication in JINS
Measurement of Through-Going Particle Momentum By Means Of Multiple Scattering With The ICARUS T600 TPC
The ICARUS collaboration has demonstrated, following the operation of a 600
ton (T600) detector at shallow depth, that the technique based on liquid Argon
TPCs is now mature. The study of rare events, not contemplated in the Standard
Model, can greatly benefit from the use of this kind of detectors. In
particular, a deeper understanding of atmospheric neutrino properties will be
obtained thanks to the unprecedented quality of the data ICARUS provides.
However if we concentrate on the T600 performance, most of the
charged current sample will be partially contained, due to the reduced
dimensions of the detector. In this article, we address the problem of how well
we can determine the kinematics of events having partially contained tracks.
The analysis of a large sample of atmospheric muons collected during the T600
test run demonstrate that, in case the recorded track is at least one meter
long, the muon momentum can be reconstructed by an algorithm that measures the
Multiple Coulomb Scattering along the particle's path. Moreover, we show that
momentum resolution can be improved by a factor two using an algorithm based on
the Kalman Filtering technique
Search for short baseline nu(e) disappearance with the T2K near detector
8 pages, 6 figures, submitted to PRD rapid communication8 pages, 6 figures, submitted to PRD rapid communicationWe thank the J-PARC staff for superb accelerator performance and the CERN NA61 collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC and CFI, Canada; Commissariat `a l’Energie Atomique and Centre National de la Recherche Scientifique–Institut National de Physique Nucle´aire et de Physique des Particules, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; Russian Science Foundation, RFBR and Ministry of Education and Science, Russia; MINECO and European Regional Development Fund, Spain; Swiss National Science Foundation and State Secretariat for Education, Research and Innovation, Switzerland; STFC, UK; and DOE, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK. In addition participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; DOE Early Career program, USA
Measurement of and charged current inclusive cross sections and their ratio with the T2K off-axis near detector
We report a measurement of cross section and the first measurements of the cross section
and their ratio
at (anti-)neutrino energies below 1.5
GeV. We determine the single momentum bin cross section measurements, averaged
over the T2K -flux, for the detector target material (mainly
Carbon, Oxygen, Hydrogen and Copper) with phase space restricted laboratory
frame kinematics of 500 MeV/c. The
results are and $\sigma(\nu)=\left( 2.41\
\pm0.022{\rm{(stat.)}}\pm0.231{\rm (syst.)}\ \right)\times10^{-39}^{2}R\left(\frac{\sigma(\bar{\nu})}{\sigma(\nu)}\right)=
0.373\pm0.012{\rm (stat.)}\pm0.015{\rm (syst.)}$.Comment: 18 pages, 8 figure
Measurements of neutrino oscillation in appearance and disappearance channels by the T2K experiment with 6.6 x 10(20) protons on target
111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee commentsWe thank the J-PARC staff for superb accelerator performance and the CERN NA61/SHINE Collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC, and CFI, Canada; CEA and CNRS/IN2P3, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; RSF, RFBR and MES, Russia; MINECO and ERDF funds, Spain; SNSF and SER, Switzerland; STFC, UK; and the U. S. Deparment of Energy, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK, and the Emerald High Performance Computing facility in the Centre for Innovation, UK. In addition, participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; and DOE Early Career program, USA
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at
the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
Measurement of the electron neutrino charged-current interaction rate on water with the T2K ND280 pi(0) detector
10 pages, 6 figures, Submitted to PRDhttp://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.112010© 2015 American Physical Society11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PR
Development of wavelength shifter coated reflectors for the ArDM argon dark matter detector
To optimise the design of the light readout in the ArDM 1-ton liquid argon
dark matter detector, a range of reflector and WLS coating combinations were
investigated in several small setups, where argon scintillation light was
generated by radioactive sources in gas at normal temperature and pressure and
shifted into the blue region by tetraphenyl butadiene (TPB). Various
thicknesses of TPB were deposited by spraying and vacuum evaporation onto
specular 3M{\small\texttrademark}-foil and diffuse
Tetratex{\small\textregistered} (TTX) substrates. Light yields of each
reflector and TPB coating combination were compared. Reflection coefficients of
TPB coated reflectors were independently measured using a spectroradiometer in
a wavelength range between 200 and 650 nm. WLS coating on the PMT window was
also studied. These measurements were used to define the parameters of the
light reflectors of the ArDM experiment. Fifteen large cm
TTX sheets were coated and assembled in the detector. Measurements in argon gas
are reported providing good evidence of fulfilling the light collection
requirements of the experiment.Comment: 21 pages, 17 figure
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