A novel large-volume Spherical Detector with Proportional Amplification read-out
I. Giomataris, I. Irastorza, I. Savvidis, S. Andriamonje, S. Aune, M. Chapelier, Ph. Charvin, P. Colas, J. Derre, E. Ferrer, M. Gros, X. F. Navick, P. Salin, J. D. Vergados
A new type of radiation detector based on a spherical geometry is presented. The detector consists of a large spherical gas volume with a central electrode forming a radial electric field. Charges deposited in the conversion volume drift to the central sensor where they are amplified and collected. We introduce a small spherical sensor located at the center acting as a proportional amplification structure. It allows high gas gains to be reached and operates in a wide range of gas pressures. Signal development and the absolute amplitude of the response are consistent with predictions. Sub-keV energy threshold with good energy resolution is achieved. This new concept has been proven to operate in a simple and robust way and allows reading large volumes with a single read-out channel. The detector performance presently achieved is already close to fulfill the demands of many challenging projects from low energy neutrino physics to dark matter detection with applications in neutron, alpha and gamma spectroscopy.
SILEM : a new gaseous detector with integrated x-y readout plane
本文报道了在EXO双β衰变实验框架内研制的气体探测器。LEM（Large Electron Multiplication）是基于GEM的电子放大栅极。它们是在纳沙泰尔开发的，对火花具有出色的抵抗力。新的SILEM网格将标准LEM的特性与网格一侧的微图案化x-y读出平面相结合。因此，它允许初级电子的放大和它们在x-y平面中的位置确定。
The possible use of a Spherical Proportional Counter for the search of neutrinoless double beta decay is investigated in the R2D2 R&D project. Dual charge and scintillation light readout may improve the detector performance. Tests were carried out with pure argon at 1.1 bar using a 6x6 mm2 silicon photomultiplier. Scintillation light was used for the first time to trigger in a spherical proportional counter. The measured drift time is in excellent agreement with the expectations from simulations. Furthermore the light signal emitted during the avalanche development exhibits features that could…
The spherical proportional counter is a versatile gaseous detector with physics applications ranging from rare event searches to fast neutron spectroscopy. In its simplest form, the detector operates with a single channel read-out, and uses pulse-shape information to reconstruct the interaction radius, which is used for background discrimination and target volume definition. Recent developments in the read-out instrumentation have enabled the use of a multi-anode read-out structure, ACHINOS. The multiple anodes provide information about the interaction position which, coupled with the radial i…
The spherical proportional counter is a gaseous detector used in a variety of applications, including direct dark matter and neutrino-less double beta decay searches. The ACHINOS multianode structure is a read-out technology that overcomes the limitations of single-anode read-out structures for large-size detectors and operation under high pressure. A resistive ACHINOS is presented, where the 3D printed central component is coated in a Diamond-Like Carbon (DLC) layer. The production and testing of the structure, in terms of stability and resolution, is described. Further applications in fundam…
A simple hole-type secondary scintillation structure (2 mm-hole, 5 mm-pitch, 5 mm-thickness) is introduced and its operation demonstrated in pure xenon in the pressure range 2-10 bar. The new device, characteristically translucent, has been manufactured through a collaboration between IGFAE and the CERN workshop, and relies entirely on radiopure materials (acrylic and copper), being extremely rugged in the presence of sparks, mechanically robust, and easily scalable, yet made through a relatively simple process. With an overall figure (at 10 bar) characterized by an energy resolution of 18.9%(…
LaBr3:Ce crystals, with photomultiplier or single SiPM readout (up to 3x3 mm$^2$) have been introduced for radiation imaging in medical physics. An R&D was pursued with 1/2" and 1" LaBr3:Ce crystals, from different producers, to realize compact large area detectors (up to some cm $^2$ area) with SiPM array readout, aiming at high light yields, good energy resolution,good detector linearity and fast time response for low-energy X-rays. The study was triggered by the FAMU experiment at the RIKEN-RAL muon facility, aiming at a precise measurement of the proton Zemach radius to solve the so-called…
For the International Large Detector (ILD) at the planned International Linear Collider (ILC) a Time Projection Chamber (TPC) is foreseen as the main tracking detector. To achieve the required point resolution, Micro Pattern Gaseous Detectors (MPGD) will be used in the amplification stage. A readout module using a stack of three Gas Electron Multipliers (GEM) for gas amplification was developed at DESY. In a test campaign at the DESY II Test Beam Facility the performance of three of these modules was investigated. In this contribution results were presented on the particle identification capab…
A Cherenkov detector based on an array of five lead fluoride ($β$-PbF$_2$) crystals of size 30 mm$\times$30 mm$\times$160 mm read out by reverse-type avalanche photodiodes (APD's) of active area 10 mm$\times$10 mm was used to measure the flux of secondary particles emerging from the annihilation of pulsed beams of antiprotons at the Antiproton Decelerator of CERN. We compared the relative photon yields of radiators made of $β$-PbF$_2$, fused silica, UV-transparent acrylic, lead glass, and a lead-free, high-refractive-index glass. Some {\it p-i-n} photodiodes were also used for the readout, but…
Crosstalk characteristics such as pulse amplitude and shape are studied with a simple PSpice model of the capacitive couplings within an MPGD. The crosstalk pulse shape can be understood as due to a CR-differentiator. Crosstalk can occur simultaneously through more than one capacitive coupling path. The crosstalk signals on these paths add differently if the signal is induced via a current source as in normal detector operation or via a voltage source as is often done in benchtop tests with an external voltage pulse generator. A few means for reducing the crosstalk are investigated with the mo…
