Technologies for obtaining radio-pure materials : methods of low radioactivity detection

This paper discusses selected problems arising from the presence of radioactive background sources in experiments searching for extremely rare processes. Physical properties of ^{42}K ions, present in argon as a progeny of ^{42}Ar, were investigated. A model of ^{42}K ions behavior in liquiefied argon is presented. Also, construction and operation of an electrostatic ^{222}Rn monitor of gaseous nitrogen is outlined

An online radon monitor for low-background detector assembly facilities

Backgrounds from long-lived radon decay products are often problematic for low-energy neutrino and rare-event experiments. These isotopes, specifically $${}^{210}\hbox {Pb}$$, $${}^{210}\hbox {Bi}$$, and $${}^{210}\hbox {Po}$$, easily plate out onto surfaces exposed to radon-loaded air. The alpha emitter $${}^{210}\hbox {Po}$$ is particularly dangerous for detectors searching for weakly-interacting dark matter particles. Neutrons produced via (\upalpha , n) reactions in detector materials are, in some cases, a residual background that can limit the sensitivity of the experiment. An effective solution is to reduce the $${}^{222}\hbox {Rn}$$ activity in the air in contact with detector components during fabrication, assembly, commissioning, and operation. We present the design, construction, calibration procedures and performance of an electrostatic radon detector made to monitor two radon-suppressed clean rooms built for the DARKSIDE-50 experiment. A dedicated data acquisition system immune to harsh operating conditions of the radon monitor is also described. A record detection limit for $${}^{222}\hbox {Rn}$$ specific activity in air achieved by the device is $$0.05\,\hbox {mBqm}^{-3}$$ (STP). The radon concentration of different air samples collected from the two DARKSIDE-50 clean rooms measured with the electrostatic detector is presented

KATANA : a charge-sensitive triggering/veto system for the Sπ\piRIT experiment

KATANA — the Kraków Array for Triggering with Amplitude discrimiNAtion, has been built and used as a trigger and Veto detector for the S$\pi$RIT TPC at RIKEN. Its construction allows for operation in magnetic field and provides a fast response for ionizing particles giving the approximate forward multiplicity and charge information. Depending on this information, trigger and veto signals are generated. The Multi-Pixel Photon Counters were used as light sensors for plastic scintillators. Performance of the detector is presented

KATANA : a charge-sensitive trigger/veto array for the SπS\pi RIT TPC

KATANA — the Krak´ow Array for Triggering with Amplitude discrimiNAtion, has been built and used as a trigger and veto detector for the SπRIT TPC at RIKEN. Its construction allows operating in magnetic field, providing fast response for ionizing particles and giving the approximate multiplicity and charge information on forward emitted reaction products. Depending on this information, trigger and veto signals are generated. Multi-Pixel Photon Counters were used as light sensors for plastic scintillators. Custom designed front-end and peripheral electronics will be presented as well

Radon Mitigation Applications at the Laboratorio Subterraneo de Canfranc (LSC)

The Laboratorio Subterraneo de Canfranc (LSC) is the Spanish national hub for low radioactivity techniques and the associated scientific and technological applications. The concentration of the airborne radon is a major component of the radioactive budget in the neighborhood of the detectors. The LSC hosts a Radon Abatement System, which delivers a radon suppressed air with 1.1 & PLUSMN;0.2 mBq/m(3) of Rn-222. The radon content in the air is continuously monitored with an Electrostatic Radon Monitor. Measurements with the double beta decay demonstrators NEXT-NEW and CROSS and the gamma HPGe detectors show the important reduction of the radioactive background due to the purified air in the vicinity of the detectors. We also discuss the use of this facility in the LSC current program which includes NEXT-100, low background biology experiments and radiopure copper electroformation equipment placed in the radon-free clean room

A novel experimental setup for rare events selection and its potential application to super-heavy elements search

The paper presents a novel instrumentation for rare events selection which was tested in our research of short-lived super-heavy elements production and detection. The instrumentation includes an active catcher multi-elements system and dedicated electronics. The active catcher located in the forward hemisphere is composed of 63 scintillator detection modules. Reaction products of damped collisions between heavy-ion projectiles and heavy-target nuclei are implanted in the fast plastic scintillators of the active catcher modules. The acquisition system trigger delivered by logical branch of the electronics allows to record the reaction products which decay via the alpha-particle emissions or spontaneous fission which take place between beam bursts. One microsecond wave form signal from FADCs contains information on heavy implanted nucleus as well as its decays

First results of GERDA Phase II and consistency with background models

The GERDA (GERmanium Detector Array) is an experiment for the search of neutrinoless double beta decay (0νββ) in (76)Ge, located at Laboratori Nazionali del Gran Sasso of INFN (Italy). GERDA operates bare high purity germanium detectors submersed in liquid Argon (LAr). Phase II of data-taking started in Dec 2015 and is currently ongoing. In Phase II 35 kg of germanium detectors enriched in (76)Ge including thirty newly produced Broad Energy Germanium (BEGe) detectors is operating to reach an exposure of 100 kg·yr within about 3 years data taking. The design goal of Phase II is to reduce the background by one order of magnitude to get the sensitivity for $T_{1/2}^{0\nu } = O\left( {{{10}^{26}}} \right){\rm{ yr}}$. To achieve the necessary background reduction, the setup was complemented with LAr veto. Analysis of the background spectrum of Phase II demonstrates consistency with the background models. Furthermore (226)Ra and (232)Th contamination levels consistent with screening results. In the first Phase II data release we found no hint for a 0νββ decay signal and place a limit of this process $T_{1/2}^{0\nu } > 5.3 \cdot {10^{25}}$ yr (90% C.L., sensitivity 4.0·10(25) yr). First results of GERDA Phase II will be presented

DarkSide status and prospects

Sem informaçãoDarkSide uses a dual-phase Liquid Argon Time Projection Chamber to search for WIMP dark matter. The current detector, DarkSide-50, is running since mid 2015 with a target of 50 kg of Argon from an underground source. Here it is presented the latest results of searches of WIMP-nucleus interactions, with WIMP masses in the GeV-TeV range, and of WIMP-electron interactions, in the sub-GeV mass range. The future of DarkSide with a new generation experiment, involving a global collaboration from all the current Argon based experiments, is presented.422-315Sem informaçãoSem informaçãoSem informaçã