On the physics and technology of gaseous particle detectors

Despite an already long and fruitful history, gaseous elementary-particle detectors remain today an important mainstay of high-energy and nuclear physics experiments and of radiation detection in general. In here we briefly describe some of the gaseous detector's main technologies and applications, along with some unsolved gas-discharge physics aspects of practical relevance.Comment: Submitted to Plasma Sources in Science and Technolog

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 Subterraneo 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 beta beta 0 nu events provides a powerful background rejection factor for the beta 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 degrees 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/mu s, which enables recording most of the tracking signals

Upgrade of the TOTEM DAQ using the Scalable Readout System (SRS)

The main goals of the TOTEM Experiment at the LHC are the measurements of the elastic and total p-p cross sections and the studies of the diffractive dissociation processes. At LHC, collisions are produced at a rate of 40 MHz, imposing strong requirements for the Data Acquisition Systems (DAQ) in terms of trigger rate and data throughput. The TOTEM DAQ adopts a modular approach that, in standalone mode, is based on VME bus system. The VME based Front End Driver (FED) modules, host mezzanines that receive data through optical fibres directly from the detectors. After data checks and formatting are applied in the mezzanine, data is retransmitted to the VME interface and to another mezzanine card plugged in the FED module. The VME bus maximum bandwidth limits the maximum first level trigger (L1A) to 1 kHz rate. In order to get rid of the VME bottleneck and improve scalability and the overall capabilities of the DAQ, a new system was designed and constructed based on the Scalable Readout System (SRS), developed in the framework of the RD51 Collaboration. The project aims to increase the efficiency of the actual readout system providing higher bandwidth, and increasing data filtering, implementing a second-level trigger event selection based on hardware pattern recognition algorithms. This goal is to be achieved preserving the maximum back compatibility with the LHC Timing, Trigger and Control (TTC) system as well as with the CMS DAQ. The obtained results and the perspectives of the project are reported. In particular, we describe the system architecture and the new Opto-FEC adapter card developed to connect the SRS with the FED mezzanine modules. A first test bench was built and validated during the last TOTEM data taking period (February 2013). Readout of a set of 3 TOTEM Roman Pot silicon detectors was carried out to verify performance in the real LHC environment. In addition, the test allowed a check of data consistency and quality

The Front-End Concentrator card for the RD51 Scalable Readout System

Conventional readout systems exist in many variants since the usual approach is to build readout electronics for one given type of detector. The Scalable Readout System (SRS) developed within the RD51 collaboration relaxes this situation considerably by providing a choice of frontends which are connected over a customizable interface to a common SRS DAQ architecture. This allows sharing development and production costs among a large base of users as well as support from a wide base of developers. The Front-end Concentrator card (FEC), a RD51 common project between CERN and the NEXT Collaboration, is a reconfigurable interface between the SRS online system and a wide range of frontends. This is accomplished by using application-specific adapter cards between the FEC and the frontends. The ensemble (FEC and adapter card are edge mounted) forms a 6U x 220mm Eurocard combo that fits on a 19 '' subchassis. Adapter cards exist already for the first applications and more are in development.We acknowledge the support of the NEXT and RD51 Collaborations and the CONSOLIDER-INGENIO2010 grant CSD2008-0037 (Canfranc Underground Physics). We also acknowledge the invaluable support from the DATE team at CERN PH-AID. We thank Michal Kubicek, from Brno University of Technology, for his help with the FPGA data recovery algorithms.Toledo Alarcón, JF.; Müller, HW.; Esteve Bosch, R.; Monzó Ferrer, JM.; Tarazona Martínez, A.; Martoiu, S. (2011). The Front-End Concentrator card for the RD51 Scalable Readout System. Journal of Instrumentation. 6(11):1-8. doi:10.1088/1748-0221/6/11/C11028S1861

The trigger system in the NEXT-DEMO detector

[EN] NEXT-DEMO is a prototype of NEXT (Neutrino Experiment with Xenon TPC), an experiment to search for neutrino-less double beta decay using a 100 kg radio-pure, 90 % enriched (136Xe isotope) high-pressure gaseous xenon TPC with electroluminescence readout. The detector is based on a PMT plane for energy measurements and a SiPM tracking plane for topological event filtering. The experiment will be located in the Canfranc Underground Laboratory in Spain. Front-end electronics, trigger and data-acquisition systems (DAQ) have been built. The DAQ is an implementation of the Scalable Readout System (RD51 collaboration) based on FPGA. Our approach for trigger is to have a distributed and reconfigurable system in the DAQ itself. Moreover, the trigger allows on-line triggering based on the detection of primary or secondary scintillation light, or a combination of both, that arrives to the PMT plane.We acknowledge the support of the NEXT and RD51collaborations, the DATE team at CERN PH-AID, and the CONSOLIDER-INGENIO2010 grant CSD2008-0037 (Canfranc Underground Physics) from the Spanish Ministry of Science and Innovation.Esteve Bosch, R.; Toledo Alarcón, JF.; Monrabal Capilla, F.; Lorca Galindo, D.; Serra Diaz-Cano, L.; Marí Romero, AF.; Gómez Cadenas, JJ.... (2012). The trigger system in the NEXT-DEMO detector. Journal of Instrumentation. 7(12):1-9. https://doi.org/10.1088/1748-0221/7/12/C12001S19712Álvarez, V., Borges, F. I. G. M., Cárcel, S., Carmona, J. M., Castel, J., Catalá, J. M., … Conde, C. A. N. (2012). NEXT-100 Technical Design Report (TDR). Executive summary. Journal of Instrumentation, 7(06), T06001-T06001. doi:10.1088/1748-0221/7/06/t06001Gómez-Cadenas, J. J., & Martín-Albo, J. (2008). NEXT, a HPXe TPC for neutrinoless double beta decay searches. Journal of Physics: Conference Series, 136(4), 042048. doi:10.1088/1742-6596/136/4/042048Fernandes, L. M. P., Freitas, E. D. C., Ball, M., Gómez-Cadenas, J. J., Monteiro, C. M. B., Yahlali, N., … Santos, J. M. F. dos. (2010). Primary and secondary scintillation measurements in a Xenon Gas Proportional Scintillation Counter. Journal of Instrumentation, 5(09), P09006-P09006. doi:10.1088/1748-0221/5/09/p09006Freitas, E. D. C., Monteiro, C. M. B., Ball, M., Gómez-Cadenas, J. J., Lopes, J. A. M., Lux, T., … dos Santos, J. M. F. (2010). Secondary scintillation yield in high-pressure xenon gas for neutrinoless double beta decay (0νββ) search. Physics Letters B, 684(4-5), 205-210. doi:10.1016/j.physletb.2010.01.013Toledo, J., Muller, H., Esteve, R., Monzó, J. M., Tarazona, A., & Martoiu, S. (2011). The Front-End Concentrator card for the RD51 Scalable Readout System. Journal of Instrumentation, 6(11), C11028-C11028. doi:10.1088/1748-0221/6/11/c1102