arXiv subjects

D. Kiang

Publications and source records attributed to D. Kiang.

5 recordsLinked to original sources

arXiv2012

Design and characterization of the SiPM tracking system of NEXT-DEMO, a demonstrator prototype of the NEXT-100 experiment

NEXT-100 experiment aims at searching the neutrinoless double-beta decay of the Xe-136 isotope using a TPC filled with a 100 kg of high-pressure gaseous xenon, with 90% isotopic enrichment. The experiment will take place at the Laboratorio Subterr\'aneo de Canfranc (LSC), Spain. NEXT-100 uses electroluminescence (EL) technology for energy measurement with a resolution better than 1% FWHM. The gaseous xenon in the TPC additionally allows the tracks of the two beta particles to be recorded, which are expected to have a length of up to 30 cm at 10 bar pressure. The ability to record the topological signature of the neutrinoless double-beta events provides a powerful background rejection factor for the double-beta experiment. In this paper, we present a novel 3D imaging concept using SiPMs coated with tetraphenyl butadiene (TPB) for the EL read out and its first implementation in NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment. The design and the first characterization measurements of the NEXT-DEMO SiPM tracking system are presented. The SiPM response uniformity over the tracking plane drawn from its gain map is shown to be better than 4%. An automated active control system for the stabilization of the SiPMs gain was developed, based on the voltage supply compensation of the gain drifts. The gain is shown to be stabilized within 0.2% relative variation around its nominal value, provided by Hamamatsu, in a temperature range of 10 degree C. The noise level from the electronics and the SiPM dark noise is shown to lay typically below the level of 10 photoelectrons (pe) in the ADC. Hence, a detection threshold at 10 pe is set for the acquisition of the tracking signals. The ADC full dynamic range (4096 channels) is shown to be adequate for signal levels of up to 200 pe/microsecond, which enables recording most of the tracking signals.

physics.ins-det↗

arXiv2012

NEXT-100 Technical Design Report (TDR). Executive Summary

In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (bbonu) in Xe-136 at the Laboratorio Subterraneo de Canfranc (LSC), in Spain. The document formalizes the design presented in our Conceptual Design Report (CDR): an electroluminescence time projection chamber, with separate readout planes for calorimetry and tracking, located, respectively, behind cathode and anode. The detector is designed to hold a maximum of about 150 kg of xenon at 15 bar, or 100 kg at 10 bar. This option builds in the capability to increase the total isotope mass by 50% while keeping the operating pressure at a manageable level. The readout plane performing the energy measurement is composed of Hamamatsu R11410-10 photomultipliers, specially designed for operation in low-background, xenon-based detectors. Each individual PMT will be isolated from the gas by an individual, pressure resistant enclosure and will be coupled to the sensitive volume through a sapphire window. The tracking plane consists in an array of Hamamatsu S10362-11-050P MPPCs used as tracking pixels. They will be arranged in square boards holding 64 sensors (8 times8) with a 1-cm pitch. The inner walls of the TPC, the sapphire windows and the boards holding the MPPCs will be coated with tetraphenyl butadiene (TPB), a wavelength shifter, to improve the light collection.

physics.ins-det↗

arXiv2000

Dirac's hole theory versus quantum field theory

Dirac's hole theory and quantum field theory are usually considered equivalent to each other. For models of a certain type, however, the equivalence may not hold as we discuss in this Letter. This problem is closely related to the validity of the Pauli principle in intermediate states of perturbation theory.

quant-ph↗

arXiv1997

Testing the Core-Halo Model on Bose-Einstein Correlation Functions

Having first performed a Monte Carlo simulation to justify the analysis technique to be used, we then analyze the Bose-Einstein correlation functions from CERN experiment NA44 in the context of the core-halo model. Although experimental resolution and error bar distribution prevents a direct observation of the halo structure, the values for the core radius and the core fraction of pions can be obtained in a straight-forward manner. These are found to be independent of the structure of the correlation function at small relative momenta of Q < 50 MeV. Hence, the omega meson decay products do not distort the Gaussian shape of the Bose-Einstein correlation function in S + Pb -> pi + pi + X reaction at CERN SPS. As we find that the "model-independent" HBT radii yield results that are quantitatively as well as qualitatively unreliable for systems with long-lived resonances, we present their corrected form that applies for correlation functions with lambda(K) < 1.

nucl-th↗

arXiv1996

How to Distinguish Hydrodynamic Models Utilizing Particle Correlations and Spectra ?

We demonstrate on examples that a simultaneous study of the Bose-Einstein correlation function and the invariant momentum distribution can be very useful in distinguishing various hydrodynamic models, which describe separately the short-range correlations in high energy hadronic reactions as measured by the NA22 collaboration. We also analyze Bose-Einstein correlation functions, measured by the NA44 experiment at CERN SPS, in the context of the core-halo model.

hep-ph↗