44 research outputs found
First operation and drift field performance of a large area double phase LAr Electron Multiplier Time Projection Chamber with an immersed Greinacher high-voltage multiplier
We have operated a liquid-argon large-electron-multiplier time-projection
chamber (LAr LEM-TPC) with a large active area of 76 40 cm and a
drift length of 60 cm. This setup represents the largest chamber ever achieved
with this novel detector concept. The chamber is equipped with an immersed
built-in cryogenic Greinacher multi-stage high-voltage (HV) multiplier, which,
when subjected to an external AC HV of 1 kV, statically
charges up to a voltage a factor of 30 higher inside the LAr vessel,
creating a uniform drift field of 0.5 kV/cm over the full drift length.
This large LAr LEM-TPC was brought into successful operation in the
double-phase (liquid-vapor) operation mode and tested during a period of
1 month, recording impressive three-dimensional images of very
high-quality from cosmic particles traversing or interacting in the sensitive
volume. The double phase readout and HV systems achieved stable operation in
cryogenic conditions demonstrating their good characteristics, which
particularly suit applications for next-generation giant-scale LAr-TPCs.Comment: 26 pages, 19 figure
Successful management of refractory pleural effusion due to systemic immunoglobulin light chain amyloidosis by vincristine adriamycin dexamethasone chemotherapy: a case report
<p>Abstract</p> <p>Introduction</p> <p>Refractory pleural effusion in systemic immunoglobulin light chain amyloidosis without cardiac decompensation is rarely reported and has a poor prognosis in general (a median survival of 1.6 months). Moreover, the optimum treatment for this condition is still undecided. This is the first report on the successful use of vincristine, adriamycin and dexamethasone chemotherapy for refractory pleural effusion due to systemic immunoglobulin light chain amyloidosis without cardiac decompensation.</p> <p>Case presentation</p> <p>We report the case of a 68-year old Japanese male with systemic immunoglobulin light chain amyloidosis presenting with bilateral pleural effusion (more severe on the right side) in the absence of cardiac decompensation that was refractory to diuretic therapy. The patient was admitted for fatigue, exertional dyspnea, and bilateral lower extremity edema. He had been receiving intermittent melphalan and prednisone chemotherapy for seven years. One month before admission, his dyspnea had got worse, and his chest radiograph showed bilateral pleural effusion; the pleural effusion was ascertained to be a transudate. The conventionally used therapeutic measures, including diuretics and thoracocentesis, failed to control pleural effusion. Administration of vincristine, adriamycin, and dexamethasone chemotherapy led to successful resolution of the effusion.</p> <p>Conclusion</p> <p>Treatment with vincristine, adriamycin, and dexamethasone chemotherapy was effective for the refractory pleural effusion in systemic immunoglobulin light chain amyloidosis without cardiac decompensation and appears to be associated with improvement in our patient's prognosis.</p
Beam and SKS spectrometers at the K1.8 beam line
High-resolution spectrometers for both incident beams and scattered particles have been constructed at the K1.8 beam line of the Hadron Experimental Facility at J-PARC. A point-to-point optics is realized between the entrance and exit of QQDQQ magnets for the beam spectrometer. Fine-pitch wire chamber trackers and hodoscope counters are installed in the beam spectrometer to accept a high rate beam up to 107 Hz. The superconducting kaon spectrometer for scattered particles was transferred from KEK with modifications to the cryogenic system and detectors. A missing-mass resolution of 1.9 ± 0.1 MeV/c2 (FWHM) was achieved for the ∑ peaks of (π±, K+) reactions on a proton target in the first physics run of E19 in 2010
Neutrino-nucleus cross sections for oscillation experiments
Neutrino oscillations physics is entered in the precision era. In this
context accelerator-based neutrino experiments need a reduction of systematic
errors to the level of a few percent. Today one of the most important sources
of systematic errors are neutrino-nucleus cross sections which in the
hundreds-MeV to few-GeV energy region are known with a precision not exceeding
20%. In this article we review the present experimental and theoretical
knowledge of the neutrino-nucleus interaction physics. After introducing
neutrino oscillation physics and accelerator-based neutrino experiments, we
overview general aspects of the neutrino-nucleus cross sections, both
theoretical and experimental views. Then we focus on these quantities in
different reaction channels. We start with the quasielastic and
quasielastic-like cross section, putting a special emphasis on multinucleon
emission channel which attracted a lot of attention in the last few years. We
review the main aspects of the different microscopic models for this channel by
discussing analogies and differences among them.The discussion is always driven
by a comparison with the experimental data. We then consider the one pion
production channel where data-theory agreement remains very unsatisfactory. We
describe how to interpret pion data, then we analyze in particular the puzzle
related to the impossibility of theoretical models and Monte Carlo to
simultaneously describe MiniBooNE and MINERvA experimental results. Inclusive
cross sections are also discussed, as well as the comparison between the
and cross sections, relevant for the CP violation
experiments. The impact of the nuclear effects on the reconstruction of
neutrino energy and on the determination of the neutrino oscillation parameters
is reviewed. A window to the future is finally opened by discussing projects
and efforts in future detectors, beams, and analysis
First muon-neutrino disappearance study with an off-axis beam
We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment