SiPMs coated with TPB : coating protocol and characterization for NEXT
V. Álvarez, J. Agramunt, M. Ball, M. Batallé, J. Bayarri, F. I. G. Borges, H. Bolink, H. Brine, S. Cárcel, J. M. Carmona, J. Castel, J. M. Catalá, S. Cebrián, A… 展开作者
V. Álvarez, J. Agramunt, M. Ball, M. Batallé, J. Bayarri, F. I. G. Borges, H. Bolink, H. Brine, S. Cárcel, J. M. Carmona, J. Castel, J. M. Catalá, S. Cebrián, A. Cervera, D. Chan, C. A. N. Conde, T. Dafni, T. H. V. T. Dias, J. Díaz, R. Esteve, P. Evtoukhovitch, J. Ferrando, L. M. P. Fernandes, P. Ferrario, A. L. Ferreira, E. Ferrer-Ribas, E. D. C. Freitas, S. A. García, A. Gil, I. Giomataris, A. Goldschmidt, E. Gómez, H. Gómez, J. J. Gómez-Cadenas, K. González, R. M. Gutiérrez, J. Hauptman, J. A. Hernando-Morata, D. C. Herrera, V. Herrero, F. J. Iguaz, I. G. Irastorza, V. Kalinnikov, L. Labarga, I. Liubarsky, J. A. M. Lopes, D. Lorca, M. Losada, G. Luzón, A. Marí, J. Martin-Albo, A. M. Méndez, T. Miller, A. Moisenko, F. Monrabal, C. M. B. Monteiro, J. M. Monzó, F. J. Mora, J. Muñoz Vidal, H. Natal da Luz, G. Navarro, M. Nebot, D. Nygren, C. A. B. Oliveira, R. Palma, J. L. Pérez Aparicio, J. Pérez, E. Radicioni, M. Quinto, J. Renner, L. Ripoll, A. Rodriguez, J. Rodriguez, F. P. Santos, J. M. F. dos Santos, L. Seguí, L. Serra, D. Shuman, C. Sofka, M. Sorel, A. Soriano, H. Spieler, J. F. Toledo, J. Torrent Collell, A. Tomás, Z. Tsamalaidze, D. Vázquez, E. Velicheva, J. F. C. A. Veloso, J. A. Villar, R. Webb, T. Weber, J. T. White, N. Yahlali
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Submitted to the Journal of Instrumentation on december 26th 2011
Silicon photomultipliers (SiPM) are the photon detectors chosen for the tracking readout in NEXT, a neutrinoless ββ decay experiment which uses a high pressure gaseous xenon time projection chamber (TPC). The reconstruction of event track and topology in this gaseous detector is a key handle for background rejection. Among the commercially available sensors that can be used for tracking, SiPMs offer important advantages, mainly high gain, ruggedness, cost-effectiveness and radio-purity. Their main drawback, however, is their non sensitivity in the emission spectrum of the xenon scintillation (peak at 175 nm). This is overcome by coating these sensors with the organic wavelength shifter tetraphenyl butadienne (TPB). In this paper we describe the protocol developed for coating the SiPMs with TPB and the measurements performed for characterizing the coatings as well as the performance of the coated sensors in the UV-VUV range.
Light detection systems in Liquid Argon Time Projection Chambers (LArTPCs) require the detection of the 128 nm light produced during argon scintillation. Most detectors use Tetraphenyl Butadiene (TPB) to shift the wavelength of the light into a range visible to Photomultiplier Tubes (PMTs). These proceedings summarize characterizations of light-guides coated with a matrix of TPB in UV transmitting acrylic which are more compact than existing LArTPC light collection systems.
Scintillation light from liquid argon is produced at 128 nm and thus must be shifted to visible wavelengths in light detection systems used for Liquid Argon Time Projection Chambers (LArTPCs). To date, designs have employed tetraphenyl butadiene (TPB) coatings on photomultiplier tubes (PMTs) or plates placed in front of the PMTs. Recently, a new approach using TPB-coated light guides was proposed. In this paper, we show that the response of lightguides coated with TPB in a UV Transmitting (UVT) acrylic matrix is very similar to that of a coating using a polystyrene (PS) matrix. We obtain a fac…
Silicon photomultipliers (SiPMs) are photosensors widely used for imaging in a variety of high energy and nuclear physics experiments. In noble-gas detectors for double-beta decay and dark matter experiments, SiPMs are attractive photosensors for imaging. However they are insensitive to the VUV scintillation emitted by the noble gases (xenon and argon). This difficulty is overcome in the NEXT experiment by coating the SiPMs with tetraphenyl butadiene (TPB) to convert the VUV light into visible light. TPB requires stringent storage and operational conditions to prevent its degradation by enviro…
Scintillation light produced in liquid argon (LAr) must be shifted from 128 nm to visible wavelengths in light detection systems used for liquid argon time-projection chambers (LArTPCs). To date, LArTPC light collection systems have employed tetraphenyl butadiene (TPB) coatings on photomultiplier tubes (PMTs) or plates placed in front of the PMTs. Recently, a new approach using TPB-coated light guides was proposed. In this paper, we report on light guides with improved attenuation lengths above 100 cm when measured in air. This is an important step in the development of meter-scale light guide…
This note describes simple simulations which were performed in order to understand the attenuation behaviors of acrylic light-guides operated in air and argon, which were characterized in \cite{Baptista:2012bf}. Whilst these simulations are only at the level of sophistication of a toy model, they illustrate interesting non-exponential light attenuation effects and the differences between operating light-guide based detectors in argon and air environments. We investigate the effects of surface absorption, surface roughness and wavelength dependence, and use a model tuned on the light-guide atte…
Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. In noble element systems, it is often coated with tetraphenyl butadiene (TPB) to allow detection of vacuum ultraviolet scintillation light. In this work this dependence is investigated for PTFE coated with TPB in air for light of wavelengths of 200~nm, 260~nm, and 450~nm. The results show that TPB-coated PTFE has a reflectance of approximately 92\% for thicknesses ranging from 5~mm to 10~mm at 450~nm, with negligible variation as a function of thickness wit…
The scintillation detection systems of liquid argon time projection chambers (LArTPCs) require wavelength shifters to detect the 128 nm scintillation light produced in liquid argon. Tetraphenyl butadiene (TPB) is a fluorescent material that can shift this light to a wavelength of 425 nm, lending itself well to use in these detectors. We can coat the glass of photomultiplier tubes (PMTs) with TPB or place TPB-coated plates in front of the PMTs. In this paper, we investigate the degradation of a chemical TPB coating in a laboratory or factory environment to assess the viability of long-term TPB …
A SensL MicroFC-SMT-60035 6x6 mm$^2$ silicon photo-multiplier coated with a NOL-1 wavelength shifter have been tested in the liquid xenon to detect the 175-nm scintillation light. For comparison, a Hamamatsu vacuum ultraviolet sensitive MPPC VUV3 3x3 mm$^2$ was tested under the same conditions. The photodetection efficiency of $13.1 \pm 2.5$% and $6.0 \pm 1.0$%, correspondingly, is obtained.
To optimise the design of the light readout in the ArDM 1-ton liquid argon dark matter detector, a range of reflector and WLS coating combinations were investigated in several small setups, where argon scintillation light was generated by radioactive sources in gas at normal temperature and pressure and shifted into the blue region by tetraphenyl butadiene (TPB). Various thicknesses of TPB were deposited by spraying and vacuum evaporation onto specular 3M{\small\texttrademark}-foil and diffuse Tetratex{\small\textregistered} (TTX) substrates. Light yields of each reflector and TPB coating comb…
ALETHEIA is a newly established dark matter direct detection project that aims at hunting for low-mass WIMPs. TPB is widely implemented in liquid helium and argon experiments to shift VUV photons to visible light. We first report that we have successfully coated $\sim 3 ~μ$m TPB on the inner walls of a 10-cm cylindrical PTFE detector; we split the coating process into two steps to have all of the surfaces being coated with the same thickness; three independent methods were applied to figure out the thickness of the TPB coating layers, and consistent results were obtained. Second, with an SEM m…
To increase the light yield of a liquid Ar (LAr) detector, we optimized the evaporation technique of tetraphenyl butadiene (TPB) on the detector surface and tested the operability of a silicon photomultiplier (SiPM), namely, the multi-pixel photon counter with through-silicon-via (TSV-MPPC, Hamamatsu Photonics K.K.) at LAr temperature. TPB converts the LAr scintillations (vacuum ultraviolet light) to visible light, which can be detected by high-sensitivity photosensors. Because the light yield depends on the deposition mass of TPB on the inner surface of the detector, we constructed a well-con…
The use of efficient wavelength-shifters from the vacuum-ultraviolet to the photosensor's range of sensitivity is a key feature in detectors for Dark Matter search and neutrino physics based on liquid argon scintillation detection. Thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor optical window is the most common solution in current and planned experiments. Detector design and response can be evaluated and correctly simulated only when the properties of the optical system in use (TPB film + substrate) a…
A large number of particle detectors employ liquid argon as their target material owing to its high scintillation yield and its ability to drift ionization charge over large distances. Scintillation light from argon is peaked at 128 nm and a wavelength shifter is required for its efficient detection. In this work, we directly compare the light yield achieved in two identical liquid argon chambers, one of which is equipped with PolyEthylene Naphthalate (PEN) and the other with TetraPhenyl Butadiene (TPB) wavelength shifter. Both chambers are lined with enhanced specular reflectors and instrumen…
For the first time secondary scintillation, generated within the holes of a thick gas electron multiplier (TGEM) immersed in liquid argon, has been observed and measured using a silicon photomultiplier device (SiPM). 250 electron-ion pairs, generated in liquid argon via the interaction of a 5.9KeV Fe-55 gamma source, were drifted under the influence of a 2.5KV/cm field towards a 1.5mm thickness TGEM, the local field sufficiently high to generate secondary scintillation light within the liquid as the charge traversed the central region of the TGEM hole. The resulting VUV light was incident on a…
The measurement of the time of flight of the two 511 keV gammas recorded in coincidence in a PET scanner provides an effective way of reducing the random background and therefore increases the scanner sensitivity, provided that the coincidence resolving time (CRT) of the gammas is sufficiently good. The best commercial PET-TOF system today (based in LYSO crystals and digital SiPMs), is the VEREOS of Philips, boasting a CRT of 316 ps (FWHM). In this paper we present a Monte Carlo investigation of the CRT performance of a PET scanner exploiting the scintillating properties of liquid xenon. We fi…
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 Subterráneo 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…
Detection of scintillation light in noble gases with wavelength-shifting optical fibers
Donostia International Physics Center, BERC Basque Excellence Research Centre（多诺西亚国际物理中心，BERC巴斯克卓越研究中心）；Ikerbasque (Basque Foundation for Science)（伊克拉巴斯克（巴斯克科学基金会））；Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València（粒子物理研究所（IFIC），西班牙国家研究委员会与瓦伦西亚大学）；Department of Physics, Universidad del Pais Vasco (UPV/EHU)（巴斯克国立大学（UPV/EHU）物理系）；Nuclear Research Center Negev（内盖夫核研究中心）
The NEXT experiment aims to observe the neutrinoless double beta decay of $^{136}$Xe in a high pressure gas TPC using electroluminescence (EL) to amplify the signal from ionization. Understanding the response of the detector is imperative in achieving a consistent and well understood energy measurement. The abundance of xenon k-shell x-ray emission during data taking has been identified as a multitool for the characterisation of the fundamental parameters of the gas as well as the equalisation of the response of the detector. The NEXT-DEMO prototype is a ~1.5 kg volume TPC filled with natural …
Production and installation of wavelength-shifting reflective light enhancers for the Short-Baseline Near Detector
Argonne National Laboratory（阿贡国家实验室）；Brookhaven National Laboratory（布鲁克海文国家实验室）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；Center for Information Technology Renato Archer（雷纳托·阿切尔信息技术中心）；University of Chicago（芝加哥大学）；Colorado State University（科罗拉多州立大学）；Columbia University（哥伦比亚大学）；University of Edinburgh（爱丁堡大学）；Fermi National Accelerator Laboratory（费米国家加速器实验室）；University of Florida（佛罗里达大学）；Illinois Institute of Technology（伊利诺伊理工学院）；Imperial College London（伦敦帝国理工学院）；University of Kansas（堪萨斯大学）；Lancaster University（兰卡斯特大学）；University of Liverpool（利物浦大学）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；Louisiana State University（路易斯安那州立大学）；University of Manchester（曼彻斯特大学）；University of Michigan（密歇根大学）；University of Minnesota（明尼苏达大学）；Mount Holyoke College（蒙特霍利约克学院）；University of Notre Dame（圣母大学）；University of Oxford（牛津大学）；University of Pennsylvania（宾夕法尼亚大学）；Queen Mary University of London（伦敦大学玛丽女王学院）；Rutgers University（罗格斯大学）；University of Sheffield（谢菲尔德大学）；University of Sussex（萨塞克斯大学）；Syracuse University（雪城大学）；University of Texas at Arlington（德克萨斯大学阿灵顿分校）；Tufts University（塔夫茨大学）；Center for Neutrino Physics, Virginia Tech（弗吉尼亚理工大学中微子物理中心）；University of Warwick（华威大学）
NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration the apparatus fully implements the NEXT-100 design concept. This is an asymmetric TPC, with an energy plane made of photomultipliers and a tracking plane made of silicon photomultipliers (SiPM) coated with TPB. The detector in this new configuration has been used to reconstruct the characteristic signature of electrons in dense gas. Demonstrating the ability to identify the MIP and "blob" regions. Moreover, t…
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…
We propose an EASY (Electroluminescent ApparatuS of high Yield) and SOFT (Separated Optimized FuncTion) time-projection chamber for the NEXT experiment, that will search for neutrinoless double beta decay (bb0nu) in Xe-136. Our experiment must be competitive with the new generation of bb0nu searches already in operation or in construction. This requires a detector with very good energy resolution (<1%), very low background con- tamination (1E-4 counts/(keV \bullet kg \bullet y)) and large target mass. In addition, it needs to be operational as soon as possible. The design described here optimi…
