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Sample records for atlas liquid argon

  1. ATLAS liquid argon calorimeter back end electronics

    CERN Document Server

    Bán, J; Bellachia, F; Blondel, A; Böttcher, S; Clark, A; Colas, Jacques; Díaz-Gómez, M; Dinkespiler, B; Efthymiopoulos, I; Escalier, M; Fayard, Lo; Gara, A; He, Y; Henry-Coüannier, F; Hubaut, F; Ionescu, G; Karev, A; Kurchaninov, L; Lafaye, R; Laforge, B; La Marra, D; Laplace, S; Le Dortz, O; Léger, A; Liu, T; Martin, D; Matricon, P; Moneta, L; Monnier, E; Oberlack, H; Parsons, J A; Pernecker, S; Perrot, G; Poggioli, L; Prast, J; Przysiezniak, H; Repetti, B; Rosselet, L; Riu, I; Schwemling, P; Simion, S; Sippach, W; Strässner, A; Stroynowski, R; Tisserant, S; Unal, G; Wilkens, H; Wingerter-Seez, I; Xiang, A; Yang, J; Ye, J

    2007-01-01

    The Liquid Argon calorimeters play a central role in the ATLAS (A Toroidal LHC Apparatus) experiment. The environment at the Large Hadron Collider (LHC) imposes strong constraints on the detectors readout systems. In order to achieve very high precision measurements, the detector signals are processed at various stages before reaching the Data Acquisition system (DAQ). Signals from the calorimeter cells are received by on-detector Front End Boards (FEB), which sample the incoming pulse every 25ns and digitize it at a trigger rate of up to 75~kHz. Off-detector Read Out Driver (ROD) boards further process the data and send reconstructed quantities to the DAQ while also monitoring the data quality. In this paper, the ATLAS Liquid Argon electronics chain is described first, followed by a detailed description of the off-detector readout system. Finally, the tests performed on the system are summarized.

  2. Commissioning of the ATLAS liquid argon calorimeters

    CERN Document Server

    Rezaie, Erfan

    ATLAS, a multi-purpose detector built at the LHC at CERN, requires an extensive commissioning campaign to be ready for proton-proton collisions. In this work, we focus on the commissioning of the liquid Argon (LAr) calorimeters, with emphasis on commissioning with cosmic rays. First we outline one phase of the commissioning work, which involves testing of the front-end electronics of the two endcap calorimeters. We then describe two cosmic ray generators as input to a Monte-Carlo simulation of cosmic rays in ATLAS, and compare their results. Finally, we explain a technique developed for this work which uses information from the Tile calorimeters to predict the timing of cosmic rays within the LAr calorimeters, because cosmic rays occur randomly in time whereas the electronics are clocked at [Special characters omitted.] . The results from this analysis tool are compared to default tools, using both simulated and real cosmic ray data in the calorimeters.

  3. The ATLAS Liquid Argon Calorimeter Construction, Integration, Commissioning

    CERN Document Server

    Aleksa, Martin

    2006-01-01

    The ATLAS liquid argon (LAr) calorimeter system consists of an electromagnetic barrel calorimeter and two end caps with electromagnetic, hadronic and forward calorimeters. The liquid argon sampling technique, with an accordion geometry was chosen for the barrel electromagnetic calorimeter (EMB) and adapted to the end cap (EMEC). The hadronic end cap calorimeter (HEC) uses a copper-liquid argon sampling technique with flat plate geometry and is subdivided in depth in two wheels per end-cap. Finally, the forward calorimeter (FCAL) is composed of three modules employing cylindrical electrodes with thin liquid argon gaps. The construction of the full calorimeter system is complete since mid-2004. Production modules constructed in the home institutes were integrated into wheels at CERN in 2003-2004, and inserted into the three cryostats. They passed their first complete cold test before the lowering into the ATLAS cavern. Results of quality checks (e.g. electrical, mechanical, ...) performed on all the 190304 read...

  4. The ATLAS Liquid Argon Calorimeter: Construction, Integration, Commissioning

    International Nuclear Information System (INIS)

    The ATLAS liquid argon (LAr) calorimeter system consists of an electromagnetic barrel calorimeter and two end caps with electromagnetic, hadronic and forward calorimeters. The liquid argon sampling technique, with an accordion geometry was chosen for the barrel electromagnetic calorimeter (EMB) and adapted to the end cap (EMEC). The hadronic end cap calorimeter (HEC) uses a copper-liquid argon sampling technique with flat plate geometry and is subdivided in depth in two wheels per end-cap. Finally, the forward calorimeter (FCAL) is composed of three modules employing cylindrical electrodes with thin liquid argon gaps.The construction of the full calorimeter system is complete since mid-2004. Production modules constructed in the home institutes were integrated into wheels at CERN in 2003-2004, and inserted into the three cryostats. They passed their first complete cold test before the lowering into the ATLAS cavern. Results of quality checks (e.g. electrical, mechanical, ...) performed on all the 190304 read-out channels after cool down will be reported. End 2004 the ATLAS barrel electromagnetic (EM) calorimeter was installed in the ATLAS cavern and since summer 2005 the front-end electronics are being connected and tested. Results of this first commissioning phase will be shown to demonstrate the high standards of quality control for our detectors

  5. The ATLAS liquid argon electromagnetic calorimeter construction status

    CERN Document Server

    Jérémie, A

    2004-01-01

    The construction and assembly of the ATLAS liquid argon electromagnetic calorimeter was described. The calorimeter was built with accordion geometry composed of lead absorbers, liquid argon as ionizing medium and highly granular readout electrodes. The calorimeter was composed of the Barrel and the End-cap, both preceded by presampler sectors to ensure complete recovery of the energy resolution. The detection of cabling errors and testing of the whole calibration chain was done by sending a pulse through the calibration circuit with single readout. (Edited abstract) 3 Refs.

  6. Readiness of the ATLAS Liquid Argon Calorimeter for LHC Collisions

    CERN Document Server

    Aad, G; Abdallah, J; Abdelalim, A A; Abdesselam, A; Abdinov, O; Abi, B; Abolins, M; Abramowicz, H; Abreu, H; Acharya, B S; Adams, D L; Addy, T N; Adelman, J; Adorisio, C; Adragna, P; Adye, T; Aefsky, S; Aguilar-Saavedra, J A; Aharrouche, M; Ahlen, S P; Ahles, F; Ahmad, A; Ahmed, H; Ahsan, M; Aielli, G; Akdogan, T; Åkesson, T P A; Akimoto, G; Akimov, A V; Aktas, A; Alam, M S; Alam, M A; Albert, J; Albrand, S; Aleksa, M; Aleksandrov, I N; Alessandria, F; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Aliev, M; Alimonti, G; Alison, J; Aliyev, M; Allport, P P; Allwood-Spiers, S E; Almond, J; Aloisio, A; Alon, R; Alonso, A; Alviggi, M G; Amako, K; Amelung, C; Ammosov, V V; Amorim, A; Amorós, G; Amram, N; Anastopoulos, C; Andeen, T; Anders, C F; Anderson, K J; Andreazza, A; Andrei, V; Anduaga, X S; Angerami, A; Anghinolfi, F; Anjos, N; Antonaki, A; Antonelli, M; Antonelli, S; Antunovic, B; Anulli, F; Aoun, S; Arabidze, G; Aracena, I; Arai, Y; Arce, A T H; Archambault, J P; Arfaoui, S; Arguin, J-F; Argyropoulos, T; Arik, E; Arik, M; Armbruster, A J; Arnaez, O; Arnault, C; Artamonov, A; Arutinov, D; Asai, M; Asai, S; Asfandiyarov, R; Ask, S; Åsman, B; Asner, D; Asquith, L; Assamagan, K; Astbury, A; Astvatsatourov, A; Atoian, G; Auerbach, B; Auge, E; Augsten, K; Aurousseau, M; Austin, N; Avolio, G; Avramidou, R; Axen, D; Ay, C; Azuelos, G; Azuma, Y; Baak, M A; Baccaglioni, G; Bacci, C; Bach, A; Bachacou, H; Bachas, K; Backes, M; Badescu, E; Bagnaia, P; Bai, Y; Bailey, D C; Bain, T; Baines, J T; Baker, O K; Baker, M D; Baltasar Dos Santos Pedrosa, F; Banas, E; Banerjee, P; Banerjee, S; Banfi, D; Bangert, A; Bansal, V; Baranov, S P; Baranov, S; Barashkou, A; Barber, T; Barberio, E L; Barberis, D; Barbero, M; Bardin, D Y; Barillari, T; Barisonzi, M; Barklow, T; Barlow, N; Barnett, B M; Barnett, R M; Baron, S; Baroncelli, A; Barr, A J; Barreiro, F; BarreiroGuimarães da Costa, J; Barrillon, P; Barros, N; Bartoldus, R; Bartsch, D; Bastos, J; Bates, R L; Bathe, S; Batkova, L; Batley, J R; Battaglia, A; Battistin, M; Bauer, F; Bawa, H S; Bazalova, M; Beare, B; Beau, T; Beauchemin, P H; Beccherle, R; Becerici, N; Bechtle, P; Beck, G A; Beck, H P; Beckingham, M; Becks, K H; Bedajanek, I; Beddall, A J; Beddall, A; Bednár, P; Bednyakov, V A; Bee, C; Begel, M; Behar Harpaz, S; Behera, P K; Beimforde, M; Belanger-Champagne, C; Bell, P J; Bell, W H; Bella, G; Bellagamba, L; Bellina, F; Bellomo, M; Belloni, A; Belotskiy, K; Beltramello, O; Ben Ami, S; Benary, O; Benchekroun, D; Bendel, M; Benedict, B H; Benekos, N; Benhammou, Y; Benincasa, G P; Benjamin, D P; Benoit, M; Bensinger, J R; Benslama, K; Bentvelsen, S; Beretta, M; Berge, D; Bergeaas Kuutmann, E; Berger, N; Berghaus, F; Berglund, E; Beringer, J; Bernardet, K; Bernat, P; Bernhard, R; Bernius, C; Berry, T; Bertin, A; Besson, N; Bethke, S; Bianchi, R M; Bianco, M; Biebel, O; Biesiada, J; Biglietti, M; Bilokon, H; Bindi, M; Binet, S; Bingul, A; Bini, C; Biscarat, C; Bitenc, U; Black, K M; Blair, R E; Blanchard, J-B; Blanchot, G; Blocker, C; Blocki, J; Blondel, A; Blum, W; Blumenschein, U; Bobbink, G J; Bocci, A; Boehler, M; Boek, J; Boelaert, N; Böser, S; Bogaerts, J A; Bogouch, A; Bohm, C; Bohm, J; Boisvert, V; Bold, T; Boldea, V; Boldyrev, A; Bondarenko, V G; Bondioli, M; Boonekamp, M; Booth, J R A; Bordoni, S; Borer, C; Borisov, A; Borissov, G; Borjanovic, I; Borroni, S; Bos, K; Boscherini, D; Bosman, M; Bosteels, M; Boterenbrood, H; Bouchami, J; Boudreau, J; Bouhova-Thacker, E V; Boulahouache, C; Bourdarios, C; Boyd, J; Boyko, I R; Bozovic-Jelisavcic, I; Bracinik, J; Braem, A; Branchini, P; Brandenburg, G W; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, B; Brau, J E; Braun, H M; Brelier, B; Bremer, J; Brenner, R; Bressler, S; Breton, D; Brett, N D; Britton, D; Brochu, F M; Brock, I; Brock, R; Brodbeck, T J; Brodet, E; Broggi, F; Bromberg, C; Brooijmans, G; Brooks, W K; Brown, G; Brubaker, E; Bruckman de Renstrom, P A; Bruncko, D; Bruneliere, R; Brunet, S; Bruni, A; Bruni, G; Bruschi, M; Buanes, T; Bucci, F; Buchanan, J; Buchholz, P; Buckley, A G; Budagov, I A; Budick, B; Büscher, V; Bugge, L; Bulekov, O; Bunse, M; Buran, T; Burckhart, H; Burdin, S; Burgess, T; Burke, S; Busato, E; Bussey, P; Buszello, C P; Butin, F; Butler, B; Butler, J M; Buttar, C M; Butterworth, J M; Byatt, T; Caballero, J; Cabrera Urbán, S; Caforio, D; Cakir, O; Calafiura, P; Calderini, G; Calfayan, P; Calkins, R; Caloba, L P; Caloi, R; Calvet, D; Camarri, P; Cambiaghi, M; Cameron, D; Campabadal-Segura, F; Campana, S; Campanelli, M; Canale, V; Canelli, F; Canepa, A; Cantero, J; Capasso, L; Capeans-Garrido, M D M; Caprini, I; Caprini, M; Capua, M; Caputo, R; Caracinha, D; Caramarcu, C; Cardarelli, R; Carli, T; Carlino, G; Carminati, L; Caron, B; Caron, S; Carrillo Montoya, G D; Carron Montero, S; Carter, A A; Carter, J R

    2010-01-01

    The ATLAS liquid argon calorimeter has been operating continuously since August 2006. At this time, only part of the calorimeter was readout, but since the beginning of 2008, all calorimeter cells have been connected to the ATLAS readout system in preparation for LHC collisions. This paper gives an overview of the liquid argon calorimeter performance measured in situ with random triggers, calibration data, cosmic muons, and LHC beam splash events. Results on the detector operation, timing performance, electronics noise, and gain stability are presented. High energy deposits from radiative cosmic muons and beam splash events allow to check the intrinsic constant term of the energy resolution. The uniformity of the electromagnetic barrel calorimeter response along eta (averaged over phi) is measured at the percent level using minimum ionizing cosmic muons. Finally, studies of electromagnetic showers from radiative muons have been used to cross-check the Monte Carlo simulation. The performance results obtained u...

  7. STATUS OF THE ATLAS LIQUID ARGON CALORIMETER AND ITS PERFORMANCE

    CERN Document Server

    Berillari, T; The ATLAS collaboration

    2011-01-01

    The liquid argon (LAr) calorimeters are used in ATLAS for all electromagnetic and for hadron calorimetry. The LAr calorimeter system consists of an electromagnetic barrel calorimeter and two endcaps with electromagnetic, hadronic and forward calorimeters. The latest status of the detector as well as problems and solutions addressed during the last years will be presented. Aspects of operation of a large detector over a long time period will be summarized and selected topics showing the performance of the detector will be shown.

  8. Status of the ATLAS Liquid Argon Calorimeter and its Performance

    CERN Document Server

    Barillari, T; The ATLAS collaboration

    2011-01-01

    The ATLAS experiment is designed to study the proton-proton collisions produced at the LHC with a centre-of-mass energy of 14 TeV. Liquid argon (LAr) sampling calorimeters are used in ATLAS for all electromagnetic calorimetry covering the pseudorapidity region |eta|<3.2, as well as for hadronic calorimetry from |eta|=1.4 to |eta|=4.8. The calorimeter system consists of an electromagnetic barrel calorimeter and two endcaps with electromagnetic (EMEC), hadronic (HEC) and forward (FCAL) calorimeters. The lead-liquid argon sampling technique with an accordion geometry was chosen for the barrel electromagnetic calorimeter (EMB) and adapted to the endcap (EMEC). This geometry allows a uniform acceptance over the whole azimuthal range without any gap. The hadronic endcap calorimeter (HEC) uses a copper-liquid argon sampling technique with plate geometry and is subdivided into two wheels in depth per end-cap. Finally, the forward calorimeter (FCAL) is composed of three modules featuring cylindrical electrodes ...

  9. The ATLAS liquid Argon calorimeters read-out system

    CERN Document Server

    Blondel, A; Fayard, L; La Marra, D; Léger, A; Matricon, P; Perrot, G; Poggioli, L; Prast, J; Riu, I; Simion, S

    2004-01-01

    The calorimetry of the ATLAS experiment takes advantage of different detectors based on the liquid Argon (LAr) technology. Signals from the LAr calorimeters are processed by various stages before being delivered to the Data Acquisition system. The calorimeter cell signals are received by the front-end boards, which digitize a predetermined number of samples of the bipolar waveform and sends them to the Read-Out Driver (ROD) boards. The ROD board receives triggered data from 1028 calorimeter cells, and determines the precise energy and timing of the signals by processing the discrete samplings of the pulse. In addition, it formats the digital stream for the following elements of the DAQ chain, and performs monitoring. The architecture and functionality of the ATLAS LAr ROD board are discussed, along with the final design of the Processing Unit boards housing the Digital Signal Processors (DSP). (9 refs).

  10. Electronics calibration board for the ATLAS liquid argon calorimeters

    International Nuclear Information System (INIS)

    To calibrate the energy response of the ATLAS liquid argon calorimeter, an electronics calibration board has been designed; it delivers a signal whose shape is close to the calorimeter ionization current signal with amplitude up to 100 mA in 50 Ω with 16 bit dynamic range. The amplitude of this signal is designed to be uniform over all calorimeters channels, stable in time and with an integral linearity much better that the electronics readout. The various R and D phases and most of the difficulties met are discussed and illustrated by many measurements. The custom design circuits are described and the layout of the ATLAS calibration board presented. The procedure used to qualify the boards is explained and the performance obtained illustrated: a dynamic range up to 3 TeV in three energy scales with an integral linearity better than 0.1% in each of them, a response uniformity better than 0.2% and a stability better than 0.1%. The performance of the board is well within the ATLAS requirements. Finally, in situ measurements done on the ATLAS calorimeter are shown to validate these performances

  11. The readout driver (ROD) for the ATLAS liquid argon calorimeters

    Science.gov (United States)

    Efthymiopoulos, Ilias

    2001-04-01

    The Readout Driver (ROD) for the Liquid Argon calorimeter of the ATLAS detector is described. Each ROD module receives triggered data from 256 calorimeter cells via two fiber-optics 1.28 Gbit/s links with a 100 kHz event rate (25 kbit/event). Its principal function is to determine the precise energy and timing of the signal from discrete samples of the waveform, taken each period of the LHC clock (25 ns). In addition, it checks, histograms, and formats the digital data stream. A demonstrator system, consisting of a motherboard and several daughter-board processing units (PUs) was constructed and is currently used for tests in the lab. The design of this prototype board is presented here. The board offers maximum modularity and allows the development and testing of different PU designs based on today's leading integer and floating point DSPs.

  12. The readout driver (ROD) for the ATLAS liquid argon calorimeters

    CERN Document Server

    Efthymiopoulos, I

    2001-01-01

    The Readout Driver (ROD) for the Liquid Argon calorimeter of the ATLAS detector is described. Each ROD module receives triggered data from 256 calorimeter cells via two fiber-optics 1.28 Gbit/s links with a 100 kHz event rate (25 kbit/event). Its principal function is to determine the precise energy and timing of the signal from discrete samples of the waveform, taken each period of the LHC clock (25 ns). In addition, it checks, histograms, and formats the digital data stream. A demonstrator system, consisting of a motherboard and several daughter-board processing units (PUs) was constructed and is currently used for tests in the lab. The design of this prototype board is presented here. The board offers maximum modularity and allows the development and testing of different PU designs based on today's leading integer and floating point DSPs. (3 refs).

  13. Response Uniformity of the ATLAS Liquid Argon Electromagnetic Calorimeter

    CERN Document Server

    Aharrouche, M; Di Ciaccio, L; El Kacimi, M; Gaumer, O; Gouanère, M; Goujdami, D; Lafaye, R; Laplace, S; Le Maner, C; Neukermans, L; Perrodo, P; Poggioli, L; Prieur, D; Przysiezniak, H; Sauvage, G; Wingerter-Seez, I; Zitoun, R; Lanni, F; Lü, L; Ma, H; Rajagopalan, S; Takai, H; Belymam, A; Benchekroun, D; Hakimi, M; Hoummada, A; Gao, Y; Stroynowsk, R; Aleksa, M; Carli, T; Fassnacht, P; Gianotti, F; Hervás, L; Lampl, W; Collot, J; Hostachy, J Y; Ledroit-Guillon, F; Malek, F; Martin, P; Viret, S; Leltchouk, M; Parsons, J A; Simion, S; Barreiro, F; Del Peso, J; Labarga, L; Oliver, C; Rodier, S; Barrillon, P; Benchouk, C; Djama, F; Hubaut, F; Monnier, E; Pralavorio, P; Sauvage, D; Serfon, C; Tisserant, S; Tóth, J; Banfi, D; Carminati, L; Cavalli, D; Costa, G; Delmastro, M; Fanti, M; Mandell, L; Mazzanti, M; Tartarelli, F; Kotov, K; Maslennikov, A; Pospelov, G; Tikhonov, Yu; Bourdarios, C; Fayard, L; Fournier, D; Iconomidou-Fayard, L; Kado, M; Parrour, G; Puzo, P; Rousseau, D; Sacco, R; Serin, L; Unal, G; Zerwas, D; Dekhissi, B; Derkaoui, J; EL Kharrim, A; Maaroufi, F; Cleland, W; Lacour, D; Laforge, B; Nikolic-Audit, I; Schwemling, Ph; Ghazlane, H; Cherkaoui El Moursli, R; Idrissi Fakhr-Eddine, A; Boonekamp, M; Kerschen, N; Mansoulié, B; Meyer, P; Schwindlingy, J; Lund-Jensen, B

    2007-01-01

    The construction of the ATLAS electromagnetic liquid argon calorimeter modules is completed and all the modules are assembled and inserted in the cryostats. During the production period four barrel and three endcap modules were exposed to test beams in order to assess their performance, ascertain the production quality and reproducibility, and to scrutinize the complete energy reconstruction chain from the readout and calibration electronics to the signal and energy reconstruction. It was also possible to check the full Monte Carlo simulation of the calorimeter. The analysis of the uniformity, resolution and extraction of constant term is presented. Typical non-uniformities of 0.5% and typical global constant terms of 0.6% are measured for the barrel and end-cap modules.

  14. Performance of the Electronic Readout of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Abreu, H; Aleksa, M; Aperio Bella, L; Archambault, JP; Arfaoui, S; Arnaez, O; Auge, E; Aurousseau, M; Bahinipati, S; Ban, J; Banfi, D; Barajas, A; Barillari, T; Bazan, A; Bellachia, F; Beloborodova, O; Benchekroun, D; Benslama, K; Berger, N; Berghaus, F; Bernat, P; Bernier, R; Besson, N; Binet, S; Blanchard, JB; Blondel, A; Bobrovnikov, V; Bohner, O; Boonekamp, M; Bordoni, S; Bouchel, M; Bourdarios, C; Bozzone, A; Braun, HM; Breton, D; Brettel, H; Brooijmans, G; Caputo, R; Carli, T; Carminati, L; Caughron, S; Cavalleri, P; Cavalli, D; Chareyre, E; Chase, RL; Chekulaev, SV; Chen, H; Cheplakov, A; Chiche, R; Citterio, M; Cojocaru, C; Colas, J; Collard, C; Collot, J; Consonni, M; Cooke, M; Copic, K; Costa, GC; Courneyea, L; Cuisy, D; Cwienk, WD; Damazio, D; Dannheim, D; De Cecco, S; De La Broise, X; De La Taille, C; de Vivie, JB; Debennerot, B; Delagnes, E; Delmastro, M; Derue, F; Dhaliwal, S; Di Ciaccio, L; Doan, O; Dudziak, F; Duflot, L; Dumont-Dayot, N; Dzahini, D; Elles, S; Ertel, E; Escalier, M; Etienvre, AI; Falleau, I; Fanti, M; Farooque, T; Favre, P; Fayard, Louis; Fent, J; Ferencei, J; Fischer, A; Fournier, D; Fournier, L; Fras, M; Froeschl, R; Gadfort, T; Gallin-Martel, ML; Gibson, A; Gillberg, D; Gingrich, DM; Göpfert, T; Goodson, J; Gouighri, M; Goy, C; Grassi, V; Gray, J; Guillemin, T; Guo, B; Habring, J; Handel, C; Heelan, L; Heintz, H; Helary, L; Henrot-Versille, S; Hervas, L; Hobbs, J; Hoffman, J; Hostachy, JY; Hoummada, A; Hrivnac, J; Hrynova, T; Hubaut, F; Huber, J; Iconomidou-Fayard, L; Iengo, P; Imbert, P; Ishmukhametov, R; Jantsch, A; Javadov, N; Jezequel, S; Jimenez Belenguer, M; Ju, XY; Kado, M; Kalinowski, A; Kar, D; Karev, A; Katsanos, I; Kazarinov, M; Kerschen, N; Kierstead, J; Kim, MS; Kiryunin, A; Kladiva, E; Knecht, N; Kobel, M; Koletsou, I; König, S; Krieger, P; Kukhtin, V; Kuna, M; Kurchaninov, L; Labbe, J; Lacour, D; Ladygin, E; Lafaye, R; Laforge, B; Lamarra, D; Lampl, W; Lanni, F; Laplace, S; Laskus, H; Le Coguie, A; Le Dortz, O; Le Maner, C; Lechowski, M; Lee, SC; Lefebvre, M; Leonhardt, K; Lethiec, L; Leveque, J; Liang, Z; Liu, C; Liu, T; Liu, Y; Loch, P; Lu, J; Ma, H; Mader, W; Majewski, S; Makovec, N; Makowiecki, D; Mandelli, L; Mangeard, PS; Mansoulie, B; Marchand, JF; Marchiori, G; Martin, D; Martin-Chassard, G; Martin dit Latour, B; Marzin, A; Maslennikov, A; Massol, N; Matricon, P; Maximov, D; Mazzanti, M; McCarthy, T; McPherson, R; Menke, S; Meyer, JP; Ming, Y; Monnier, E; Mooshofer, P; Neganov, A; Niedercorn, F; Nikolic-Audit, I; Nugent, IM; Oakham, G; Oberlack, H; Ocariz, J; Odier, J; Oram, CJ; Orlov, I; Orr, R; Parsons, JA; Peleganchuk, S; Penson, A; Perini, L; Perrodo, P; Perrot, G; Perus, A; Petit, E; Pisarev, I; Plamondon, M; Poffenberger, P; Poggioli, L; Pospelov, G; Pralavorio, P; Prast, J; Prudent, X; Przysiezniak, H; Puzo, P; Quentin, M; Radeka, V; Rajagopalan, S; Rauter, E; Reimann, O; Rescia, S; Resende, B; Richer, JP; Ridel, M; Rios, R; Roos, L; Rosenbaum, G; Rosenzweig, H; Rossetto, O; Roudil, W; Rousseau, D; Ruan, X; Rudert, A; Rusakovich, N; Rusquart, P; Rutherfoord, J; Sauvage, G; Savine, A; Schaarschmidt, J; Schacht, P; Schaffer, A; Schram, M; Schwemling, P; Seguin Moreau, N; Seifert, F; Serin, L; Seuster, R; Shalyugin, A; Shupe, M; Simion, S; Sinervo, P; Sippach, W; Skovpen, K; Sliwa, R; Soukharev, A; Spano, F; Stavina, P; Straessner, A; Strizenec, P; Stroynowski, R; Talyshev, A; Tapprogge, S; Tarrade, F; Tartarelli, GF; Teuscher, R; Tikhonov, Yu; Tocut, V; Tompkins, D; Thompson, P; Tisserant, S; Todorov, T; Tomasz, F; Trincaz-Duvoid, S; Trinh, Thi N; Trochet, S; Trocme, B; Tschann-Grimm, K; Tsionou, D; Ueno, R; Unal, G; Urbaniec, D; Usov, Y; Voss, K; Veillet, JJ; Vincter, M; Vogt, S; Weng, Z; Whalen, K; Wicek, F; Wilkens, H; Wingerter-Seez, I; Wulf, E; Yang, Z; Ye, J; Yuan, L; Yurkewicz, A; Zarzhitsky, P; Zerwas, D; Zhang, H; Zhang, L; Zhou, N; Zimmer, J; Zitoun, R; Zivkovic, L

    2010-01-01

    The ATLAS detector has been designed for operation at the Large Hadron Collider at CERN. ATLAS includes electromagnetic and hadronic liquid argon calorimeters, with almost 200,000 channels of data that must be sampled at the LHC bunch crossing frequency of 40 MHz. The calorimeter electronics calibration and readout are performed by custom electronics developed specifically for these purposes. This paper describes the system performance of the ATLAS liquid argon calibration and readout electronics, including noise, energy and time resolution, and long term stability, with data taken mainly from full-system calibration runs performed after installation of the system in the ATLAS detector hall at CERN.

  15. The clock and control system for the ATLAS Liquid Argon Calorimeter Phase-I upgrade

    International Nuclear Information System (INIS)

    A Liquid-argon Trigger Digitizer Board (LTDB) is being developed to upgrade the ATLAS Liquid Argon Calorimeter Phase-I trigger electronics. The LTDB located at the front end needs to obtain the clock signals and be configured and monitored remotely from the back end. A clock and control system is being developed for the LTDB and the major functions of the system have been evaluated. The design and evaluation of the clock and control system are presented in this paper

  16. Design Principles and Operational Results of the Cryogenic System for the ATLAS Liquid Argon Calorimeter

    CERN Document Server

    Fabre, C; Chalifour, M; Gonidec, G; Passardi, Giorgio; Petit, P; Pezzetti, M; Wicek, F

    2009-01-01

    The ATLAS liquid argon calorimeter housed in three independent cryostats containing a total argon volume of about 78 m3 has been installed in the underground cavern. The three detectors have been cooled down following stringent temperature gradient limits and have been filled with liquid argon. The cryostats are now in a stable condition for periods going up to almost two years. The temperature uniformity within each of the three detector volumes is found to be within 70 mK rms, while the temperature stability stays below 5 mK rms.

  17. Liquid argon pollution tests of ATLAS detector materials at the IBR-2 reactor in Dubna

    CERN Document Server

    Leroy, C; Golubyh, S M; Kukhtin, V; Merkulovm L; Minashkin, V F; Golikov, V V; Kulagin, E N; Luschikov, V; Golovanov, L B; Borzunov, Yu T; Chumakov, V; Tsvinev, A P; Shalyugin, A N

    2002-01-01

    aA cold irradiation test facility operated at the IBR-2 reactor of JINR, Dubna, is used to investigate the behaviour under neutron and gamma irradiations of samples of materials and equipments to be used in the ATLAS forward (FCAL) and the hadronic end cap (HEC) liquid argon calorimeters. The samples under study are immersed in a liquid argon cryostat and exposed to fast neutron (E/sub n/ >or= 100 keV) fluences of about 10/sup 16/ n cm/sup -2/ equivalent to the neutron fluence accumulated in FCAL during ten years of LHC operation. An alpha -cell is used to check for possible outgassing due to irradiation of the samples immersed in liquid argon and to monitor the liquid argon purity. The results of various irradiation tests performed at this facility are reported. (6 refs).

  18. Drift time measurement in the ATLAS liquid argon electromagnetic calorimeter using cosmic muons

    DEFF Research Database (Denmark)

    Aad..[], G.; Dam, Mogens; Hansen, Jørgen Beck; Hansen, John Renner; Hansen, Jørn Dines; Hansen, Peter Henrik; Xella, Stefania; Klinkby, Esben Bryndt; Nilsson, Björn Stefan

    2010-01-01

    The ionization signals in the liquid argon of the ATLAS electromagnetic calorimeter are studied in detail using cosmic muons. In particular, the drift time of the ionization electrons is measured and used to assess the intrinsic uniformity of the calorimeter gaps and estimate its impact on the...

  19. ATLAS endcap liquid argon calorimeters. Description and construction of the cryostats

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Guy; Prat, Serge; Veillet, Jean-Jacques [Laboratoire de l' Accelerateur Lineaire IN2P3-CNRS et Universite de Paris-Sud 11, BP 34, F-91898 Orsay Cedex (France)

    2006-05-15

    All forward calorimeters of the ATLAS detector use the same detection technique, energy loss in passive plates, followed by ionisation and charge detection in liquid argon. They are therefore all grouped in the same vessel which must basically support and keep in place the heavy plates and the detection electrodes and maintain liquid argon at cold and stable temperature. Taking into account all the constraints as detailed below, and the overall detector size, 5 meter diameter by 3 meter length this was quite a challenge. The design, construction and tests of these two cryostats, up to their delivery at CERN, are described in this document. These two cryostats are a joint 'in kind' contribution to the Atlas experiment of LAL (Orsay), Max Planck Institute (Muenchen) and Wuppertal University (Wuppertal) and have been designed and built under the responsibility of LAL (Orsay) with contributions of the technical groups of the above institutions and of ATLAS-CERN. (authors)

  20. ATLAS endcap liquid argon calorimeters. Description and construction of the cryostats

    International Nuclear Information System (INIS)

    All forward calorimeters of the ATLAS detector use the same detection technique, energy loss in passive plates, followed by ionisation and charge detection in liquid argon. They are therefore all grouped in the same vessel which must basically support and keep in place the heavy plates and the detection electrodes and maintain liquid argon at cold and stable temperature. Taking into account all the constraints as detailed below, and the overall detector size, 5 meter diameter by 3 meter length this was quite a challenge. The design, construction and tests of these two cryostats, up to their delivery at CERN, are described in this document. These two cryostats are a joint 'in kind' contribution to the Atlas experiment of LAL (Orsay), Max Planck Institute (Muenchen) and Wuppertal University (Wuppertal) and have been designed and built under the responsibility of LAL (Orsay) with contributions of the technical groups of the above institutions and of ATLAS-CERN. (authors)

  1. Liquid Argon Pollution Tests of the ATLAS Detector Materials at IBR-2 Reactor in Dubna

    CERN Document Server

    Leroy, C; Cheplakov, A P; Chumakov, V; Golikov, V; Golovanov, L B; Golubyh, S M; Kukhtin, V; Kulagin, E; Luschikov, V; Minashkin, V F; Shalyugin, A N; Tsvinev, A P

    1999-01-01

    A cold test facility has been in operation since October 1998 at the IBR-2 reactor of JINR, Dubna. During four measurement campaigns, various samples of the ATLAS forward (FCAL) and hadronic end cap (HEC) calorimeter materials have been exposed to a fast neutron ($E_n \\geq 100$ keV) fluence of about 10$^{16}$~n~cm$^{-2}$. The samples were immersed in a liquid argon cryostat, and an $\\alpha$-cell has been used as purity monitor. Results of the liquid argon pollution study obtained during these measurement campaigns are presented.

  2. Liquid argon pollution tests of the ATLAS detector materials at IBR-2 reactor in Dubna

    International Nuclear Information System (INIS)

    A cold test facility has been in operation since October 1998 at the IBR-2 reactor of JINR, Dubna. During four measurement campaigns, various samples of the ATLAS forward (FCAL) and hadronic end-cap (HEC) calorimeter materials have been exposed to a fast neutron (En ≥ 100 keV) fluence of about 1016 cm-2. The samples were immersed in a liquid argon cryostat, and an α cell has been used as a purity monitor. Results of the liquid argon pollution study obtained during these measurement campaigns are presented

  3. The clock distribution system for the ATLAS Liquid Argon Calorimeter Phase-I Upgrade Demonstrator

    International Nuclear Information System (INIS)

    A prototype Liquid-argon Trigger Digitizer Board (LTDB), called the LTDB Demonstrator, has been developed to demonstrate the functions of the ATLAS Liquid Argon Calorimeter Phase-I trigger electronics upgrade. Forty Analog-to-Digital converters and four FPGAs with embedded multi-gigabit-transceivers on each Demonstrator need high quality clocks. A clock distribution system based on commercial components has been developed for the Demonstrator. The design of the clock distribution system is presented. The performance of the clock distribution system has been evaluated. The components used in the clock distribution system have been qualified to meet radiation tolerance requirements of the Demonstrator

  4. Irradiation tests of readout chain components of the ATLAS liquid argon calorimeters

    CERN Document Server

    Leroy, C; Golikov, V; Golubyh, S M; Kukhtin, V; Kulagin, E; Luschikov, V; Minashkin, V F; Shalyugin, A N

    1999-01-01

    Various readout chain components of the ATLAS liquid argon calorimeters have been exposed to high neutron fluences and $gamma$-doses at the irradiation test facility of the IBR-2 reactor of JINR, Dubna. Results of the capacitance and impedance measurements of coaxial cables are presented. Results of peeling tests of PC board samples (kapton and copper strips) as a measure of the bonding agent irradiation hardness are also reported.

  5. Radiation hard micro-coaxial cables for the ATLAS liquid argon calorimeters

    CERN Document Server

    Bonivento, W; Imbert, P; de La Taille, C

    2000-01-01

    The ATLAS collaboration has chosen for the electromagnetic barrel calorimeter and for all the end-cap calorimeters a sampling technique, with liquid argon as the active medium. The read-out electronics and the calibration pulsers are located in boxes outside the cryostats housing the detectors. Signals are transmitted between the detectors and the electronic boxes through custom-designed micro- coaxial cables, which are the subject of this paper. These cables have to satisfy very stringent tolerances in terms of signal transmission, dimensions and radiation hardness. Following a successful pre-series production, these cables have been selected for equipping the ATLAS calorimeter. (16 refs).

  6. Status of the ATLAS Liquid Argon Calorimeter and its performance after one year of LHC operation

    CERN Document Server

    "Hoffman, J A; The ATLAS collaboration

    2011-01-01

    The ATLAS experiment is designed to study the proton-proton collisions produced at the LHC with a centre-of-mass energy of 14 TeV. Liquid argon (LAr) sampling calorimeters are used in ATLAS for all electromagnetic calorimetry covering the pseudorapidity region η<3.2, as well as for hadronic calorimetry from η=1.4 to η=4.8. The calorimeter system consists of an electromagnetic barrel calorimeter and two endcaps with electromagnetic (EMEC), hadronic (HEC) and forward (FCAL) calorimeters. The lead-liquid argon sampling technique with an accordion geometry was chosen for the barrel electromagnetic calorimeter (EMB) and adapted to the endcap (EMEC). This geometry allows a uniform acceptance over the whole azimuthal range without any gap. The hadronic endcap calorimeter (HEC) uses a copper-liquid argon sampling technique with plate geometry and is subdivided into two wheels in depth per end-cap. Finally, the forward calorimeter (FCAL) is composed of three modules featuring cylindrical electrodes with thin...

  7. Purity control system of the liquid argon calorimeter of the ATLAS experiment

    International Nuclear Information System (INIS)

    At the ATLAS detector (LHC at CERN) a Liquid Argon calorimeter is used to precisely measure the energy of the electromagnetic interacting particles. Particles deposit their energy in the calorimeter by creating a particle shower. The ionization of the Liquid-Argon due to the shower particles can be used to determine the energy of the initial particle. Possible electronegative impurities in the calorimeter could reduce the ionization which would lead to a worse energy resolution. In order to monitor the purity of the Liquid-Argon several purity monitors are distributed over the calorimeter. Each monitor consists of a ionization chamber with two radioactive sources (241Am and 207Bi). The decay particles of the probes create a certain, known amount of charge carrier that are collected by applying an electromagnetic field. The measurement of the signal amplitude from these charge carriers can be used to measure the purity of the Liquid Argon. This talk gives an overview of the system with a focus of a new implementation of a OPC-UA server that reads out the monitors and determines the purity values. In addition results on the long term stability of the purity are shown.

  8. Drift Time Measurement in the ATLAS Liquid Argon Electromagnetic Calorimeter using Cosmic Muons

    CERN Document Server

    Aad, G; Abdallah, J; Abdelalim, A A; Abdesselam, A; Abdinov, O; Abi, B; Abolins, M; Abramowicz, H; Abreu, H; Acharya, B S; Adams, D L; Addy, T N; Adelman, J; Adorisio, C; Adragna, P; Adye, T; Aefsky, S; Aguilar-Saavedra, J A; Aharrouche, M; Ahlen, S P; Ahles, F; Ahmad, A; Ahmed, H; Ahsan, M; Aielli, G; Akdogan, T; Åkesson, T P A; Akimoto, G; Akimov, A V; Aktas, A; Alam, M S; Alam, M A; Albert, J; Albrand, S; Aleksa, M; Aleksandrov, I N; Alessandria, F; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Aliev, M; Alimonti, G; Alison, J; Aliyev, M; Allport, P P; Allwood-Spiers, S E; Almond, J; Aloisio, A; Alon, R; Alonso, A; Alviggi, M G; Amako, K; Amelung, C; Ammosov, V V; Amorim, A; Amorós, G; Amram, N; Anastopoulos, C; Andeen, T; Anders, C F; Anderson, K J; Andreazza, A; Andrei, V; Anduaga, X S; Angerami, A; Anghinolfi, F; Anjos, N; Antonaki, A; Antonelli, M; Antonelli, S; Antos, J; Antunovic, B; Anulli, F; Aoun, S; Arabidze, G; Aracena, I; Arai, Y; Arce, A T H; Archambault, J P; Arfaoui, S; Arguin, J F; Argyropoulos, T; Arik, E; Arik, M; Armbruster, A J; Arnaez, O; Arnault, C; Artamonov, A; Arutinov, D; Asai, M; Asai, S; Asfandiyarov, R; Ask, S; Åsman, B; Asner, D; Asquith, L; Assamagan, K; Astbury, A; Astvatsatourov, A; Atoian, G; Auerbach, B; Auge, E; Augsten, K; Aurousseau, M; Austin, N; Avolio, G; Avramidou, R; Axen, D; Ay, C; Azuelos, G; Azuma, Y; Baak, M A; Bacci, C; Bach, A; Bachacou, H; Bachas, K; Backes, M; Badescu, E; Bagnaia, P; Bai, Y; Bailey, D C; Bain, T; Baines, J T; Baker, O K; Baker, M D; Baker, S; Baltasar Dos Santos Pedrosa, F; Banas, E; Banerjee, P; Banerjee, S; Banfi, D; Bangert, A; Bansal, V; Baranov, S P; Baranov, S; Barashkou, A; Barber, T; Barberio, E L; Barberis, D; Barbero, M; Bardin, D Y; Barillari, T; Barisonzi, M; Barklow, T; Barlow, N; Barnett, B M; Barnett, R M; Baron, S; Baroncelli, A; Barr, A J; Barreiro, F; Barreiro Guimarães da Costa, J; Barrillon, P; Barros, N; Bartoldus, R; Bartsch, D; Bastos, J; Bates, R L; Batkova, L; Batley, J R; Battaglia, A; Battistin, M; Bauer, F; Bawa, H S; Bazalova, M; Beare, B; Beau, T; Beauchemin, P H; Beccherle, R; Becerici, N; Bechtle, P; Beck, G A; Beck, H P; Beckingham, M; Becks, K H; Bedajanek, I; Beddall, A J; Beddall, A; Bednár, P; Bednyakov, V A; Bee, C; Begel, M; Behar Harpaz, S; Behera, P K; Beimforde, M; Belanger-Champagne, C; Bell, P J; Bell, W H; Bella, G; Bellagamba, L; Bellina, F; Bellomo, M; Belloni, A; Belotskiy, K; Beltramello, O; Ben Ami, S; Benary, O; Benchekroun, D; Bendel, M; Benedict, B H; Benekos, N; Benhammou, Y; Benincasa, G P; Benjamin, D P; Benoit, M; Bensinger, J R; Benslama, K; Bentvelsen, S; Beretta, M; Berge, D; Bergeaas Kuutmann, E; Berger, N; Berghaus, F; Berglund, E; Beringer, J; Bernardet, K; Bernat, P; Bernhard, R; Bernius, C; Berry, T; Bertin, A; Besana, M I; Besson, N; Bethke, S; Bianchi, R M; Bianco, M; Biebel, O; Biesiada, J; Biglietti, M; Bilokon, H; Bindi, M; Binet, S; Bingul, A; Bini, C; Biscarat, C; Bitenc, U; Black, K M; Blair, R E; Blanchard, J B; Blanchot, G; Blocker, C; Blocki, J; Blondel, A; Blum, W; Blumenschein, U; Bobbink, G J; Bocci, A; Boehler, M; Boek, J; Boelaert, N; Böser, S; Bogaerts, J A; Bogouch, A; Bohm, C; Bohm, J; Boisvert, V; Bold, T; Boldea, V; Boldyrev, A; Bondarenko, V G; Bondioli, M; Boonekamp, M; Bordoni, S; Borer, C; Borisov, A; Borissov, G; Borjanovic, I; Borroni, S; Bos, K; Boscherini, D; Bosman, M; Bosteels, M; Boterenbrood, H; Bouchami, J; Boudreau, J; Bouhova-Thacker, E V; Boulahouache, C; Bourdarios, C; Boyd, J; Boyko, I R; Bozovic-Jelisavcic, I; Bracinik, J; Braem, A; Branchini, P; Brandenburg, G W; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, B; Brau, J E; Braun, H M; Brelier, B; Bremer, J; Brenner, R; Bressler, S; Breton, D; Britton, D; Brochu, F M; Brock, I; Brock, R; Brodbeck, T J; Brodet, E; Broggi, F; Bromberg, C; Brooijmans, G; Brooks, W K; Brown, G; Brubaker, E; Bruckman de Renstrom, P A; Bruncko, D; Bruneliere, R; Brunet, S; Bruni, A; Bruni, G; Bruschi, M; Buanes, T; Bucci, F; Buchanan, J; Buchholz, P; Buckley, A G; Budagov, I A; Budick, B; Büscher, V; Bugge, L; Bulekov, O; Bunse, M; Buran, T; Burckhart, H; Burdin, S; Burgess, T; Burke, S; Busato, E; Bussey, P; Buszello, C P; Butin, F; Butler, B; Butler, J M; Buttar, C M; Butterworth, J M; Byatt, T; Caballero, J; Cabrera Urbán, S; Caforio, D; Cakir, O; Calafiura, P; Calderini, G; Calfayan, P; Calkins, R; Caloba, L P; Caloi, R; Calvet, D; Camarri, P; Cambiaghi, M; Cameron, D; Campabadal Segura, F; Campana, S; Campanelli, M; Canale, V; Canelli, F; Canepa, A; Cantero, J; Capasso, L; Capeans Garrido, M D M; Caprini, I; Caprini, M; Capua, M; Caputo, R; Caracinha, D; Caramarcu, C; Cardarelli, R; Carli, T; Carlino, G; Carminati, L; Caron, B; Caron, S; Carrillo Montoya, G D; Carron Montero, S; Carter, A A; Carter, J R; Carvalho, J; Casadei, D

    2010-01-01

    The ionization signals in the liquid argon of the ATLAS electromagnetic calorimeter are studied in detail using cosmic muons. In particular, the drift time of the ionization electrons is measured and used to assess the intrinsic uniformity of the calorimeter gaps and estimate its impact on the constant term of the energy resolution. The drift times of electrons in the cells of the second layer of the calorimeter are uniform at the level of 1.3% in the barrel and 2.7% in the endcaps. This leads to an estimated contribution to the constant term of 0.29% in the barrel and 0.53% in the endcaps. The same data are used to measure the drift velocity of ionization electrons in liquid argon, which is found to be 4.61 +- 0.07 mm/microsecond at 88.5 K and 1 kV/mm.

  9. The ATLAS Liquid Argon Electromagnetic EndCap Calorimeter Construction and tests

    CERN Document Server

    Rodier, S; Del Peso, J

    2003-01-01

    This thesis has been carried out within the ATLAS collaboration. ATLAS is one of the two multipurpose experiments approved for data taking at the Large Hadron Collider (LHC) at CERN. The main goals of this experiment are, to find the Higgs boson, the missing piece in the otherwise so succesful Standard Model of Particle Physics, and to look for physics beyond the Standard Model up to a scale of 1TeV. For this purpose, electromagnetic (EM) calorimetry play a key role. The ATLAS Collaboration has chosen a Liquid Argon (LAr) option with lead as passive material. The liquid Argon Calorimeter is divided into two main subdetectors, the barrel and the end caps (EC). The design and construction of the LAr EM EC calorimeter is the responsability of the groups at Centre de Physique de Marseille (CPPM) and the Universidad Autonoma de Madrid (UAM)following the guideline developed by the research and development working, group 3 for LHC detectors (RD3). The sharing of responsabilities is such that CPPM provides spacers an...

  10. Low voltage control for the liquid argon hadronic end-cap calorimeter of ATLAS

    CERN Document Server

    Brettel, H; Habring, J; Oberlack, H; Schacht, P

    2002-01-01

    At the ATLAS detector a SCADA system surveys and controls the sub- detectors. The link is realized by PVSS2 software and a CanBus hardware system. The low voltages for the Hadronic Endcaps of the liquid argon calorimeter are produced by DC/DC-converters in the power boxes and split into 320 channels corresponding to the pre- amplifier and summing boards in the cryostat. Six units of a prototype distribution board are currently under test. Each of it contains 2 ELMBs as CanBus interface, a FPGA of type QL3012 for digital control and 30 low voltage regulators for the individual fine adjustments of the outputs.

  11. The ATLAS Liquid Argon Calorimeters At The Dawn Of LHC Run-2

    CERN Document Server

    Camincher, Clement; The ATLAS collaboration

    2015-01-01

    The Liquid Argon Calorimeters are key sub-detectors of ATLAS. They are essential to detect and measure the properties of electrons, photons and are also crucial for jets and missing transverse energy measurements. During the LHC shutdown in 2013-2014, the hardware and the software have been optimized to improve their reliability. The first collisions allows to assess the performance of the detector in the LHC Run-2 real conditions. In view of the next LHC Run in 2020, an upgrade of the level-1 trigger system is also under test. A status at the restart of the LHC Run-2 is presented in this document.

  12. Development of ATLAS Liquid Argon Calorimeter Read-out Electronics for the HL-LHC

    CERN Document Server

    Newcomer, Mitchel; The ATLAS collaboration

    2015-01-01

    The high-luminosity phase of the Large Hadron Collider will provide a 5-7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon Calorimeters and their read-out system. An improved trigger system with higher acceptance rate and longer latency and a better radiation tolerance require an upgrade of the read-out electronics. Concepts for the future read-out of the 183.000 calorimeter channels at 40-80 MHz and 16 bit dynamic range, and the development of radiation tolerant, low noise, low power and high-bandwidth electronic components will be presented.

  13. The ATLAS liquid argon calorimeter high-voltage system: commissioning, optimisation, and LHC relative luminosity measurement.

    CERN Document Server

    Arfaoui, Samir; Monnier, E

    2011-01-01

    The main goals of the ATLAS scientific programme are the observation or exclusion of physics beyond the Standard Model (SM), as well as the measurement of production cross-sections of SM processes. In oder to do so,it is important to measure the luminosity at the interaction point with great precision. The ATLAS luminosity is extracted using several detectors with varying efficiencies and acceptances. Different methods, such as inclusive - or coincidence - event counting and calorimeter integrated current measurements, are calibrated and cross-compared to provide the most accurate luminosity determination. In order to provide more cross-checks and a better control on the systematic uncertainties, an independent measurement using the liquid argon (LAr) forward calorimeter (FCal), based on the readout current of its high-voltage system, has been developed. This document describes how the LAr calorimeter high-voltage system has been installed and commissioned, as well as its application to a relative luminosity ...

  14. Monitoring and data quality assessment of the ATLAS liquid argon calorimeter

    CERN Document Server

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Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Gunther, Jaroslav; Guo, Jun; Gupta, Shaun; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guttman, Nir; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Haefner, Petra; Hageboeck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Hall, David; Halladjian, Garabed; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Hanke, Paul; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Paul Fraser; Hartjes, Fred; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Lukas; Heisterkamp, Simon; Hejbal, Jiri; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, James; Henderson, Robert; Hengler, Christopher; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herrberg-Schubert, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hofmann, Julia Isabell; Hohlfeld, Marc; Holmes, Tova Ray; Hong, Tae Min; Hooft van Huysduynen, Loek; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Xueye; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Ideal, Emma; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikematsu, Katsumasa; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Inamaru, Yuki; Ince, Tayfun; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Iturbe Ponce, Julia Mariana; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Matthew; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javůrek, Tomáš; Jeanty, Laura; Jeng, Geng-yuan; Jen-La Plante, Imai; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Joergensen, Morten Dam; Johansson, Erik; Johansson, Per; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Jussel, Patrick; Juste Rozas, Aurelio; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karastathis, Nikolaos; Karnevskiy, Mikhail; Karpov, Sergey; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Katre, Akshay; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Kehoe, Robert; Keil, Markus; Keller, John; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hee Yeun; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kitamura, Takumi; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolanoski, Hermann; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Köneke, Karsten; König, Adriaan; König, Sebastian; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kreiss, Sven; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kurumida, Rie; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laier, Heiko; Lambourne, Luke; Lammers, Sabine; Lampen, Caleb; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Le, Bao Tran; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire, Alexandra; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzen, Georg; Lenzi, Bruno; Leone, Robert; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lester, Christopher; Lester, Christopher Michael; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Lindquist, Brian Edward; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Jonathan; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Losty, Michael; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lungwitz, Matthias; Lynn, David; Lysak, Roman; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Macina, Daniela; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeno, Mayuko; Maeno, Tadashi; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mamuzic, Judita; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mantifel, Rodger; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marques, Carlos; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Homero; Martinez, Mario; Martin-Haugh, Stewart; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Matsunaga, Hiroyuki; Matsushita, Takashi; Mättig, Peter; Mättig, Stefan; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazzaferro, Luca; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Medinnis, Michael; Meehan, Samuel; Meera-Lebbai, Razzak; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mendoza Navas, Luis; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Meric, Nicolas; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Moeller, Victoria; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Mönig, Klaus; Monini, Caterina; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Klemens; Mueller, Thibaut; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murillo Quijada, Javier Alberto; Murray, Bill; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagai, Yoshikazu; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Nanava, Gizo; Narayan, Rohin; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nuti, Francesco; O'Brien, Brendan Joseph; O'grady, Fionnbarr; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Ohshima, Takayoshi; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pearce, James; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penwell, John; Perepelitsa, Dennis; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petteni, Michele; Pettersson, Nora Emilia; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pingel, Almut; Pinto, Belmiro; Pires, Sylvestre; Pizio, Caterina; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Poddar, Sahill; Podlyski, Fabrice; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospelov, Guennady; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopapadaki, Eftychia-sofia; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Przysiezniak, Helenka; Ptacek, Elizabeth; Pueschel, Elisa; Puldon, David; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qin, Gang; Quadt, Arnulf; Quarrie, David; Quayle, William; Quilty, Donnchadha; Qureshi, Anum; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Ragusa, Francesco; Rahal, Ghita; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Rangel-Smith, Camila; Rao, Kanury; Rauscher, Felix; Rave, Tobias Christian; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reinsch, Andreas; Reisin, Hernan; Relich, Matthew; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Ridel, Melissa; Rieck, Patrick; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodrigues, Luis; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romeo, Gaston; Romero Adam, Elena; Rompotis, Nikolaos; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Anthony; Rose, Matthew; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Christian; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruthmann, Nils; Ruzicka, Pavel; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sacerdoti, Sabrina; Saddique, Asif; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Sauvage, Gilles; Sauvan, Emmanuel; Savard, Pierre; Savu, Dan Octavian; Sawyer, Craig; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaelicke, Andreas; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R~Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Christopher; Schmitt, Sebastian; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schramm, Steven; Schreyer, Manuel; Schroeder, Christian; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwartzman, Ariel; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Scifo, Estelle; Sciolla, Gabriella; Scott, Bill; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellers, Graham; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Serre, Thomas; Seuster, Rolf; Severini, Horst; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Sherwood, Peter; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Shushkevich, Stanislav; Sicho, Petr; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Song, Hong Ye; Soni, Nitesh; Sood, Alexander; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soualah, Rachik; Soueid, Paul; Soukharev, Andrey; South, David; Spagnolo, Stefania; Spanò, Francesco; Spearman, William Robert; Spighi, Roberto; Spigo, Giancarlo; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Stavina, Pavel; Steele, Genevieve; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoerig, Kathrin; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramania, Halasya Siva; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Svatos, Michal; Swedish, Stephen; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tamsett, Matthew; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tapprogge, Stefan; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thoma, Sascha; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Tran, Huong Lan; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ugland, Maren; Uhlenbrock, Mathias; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Virzi, Joseph; Vitells, Ofer; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Wolfgang; Wagner, Peter; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chao; Wang, Chiho; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Xiaoxiao; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watanabe, Ippei; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wittig, Tobias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wright, Michael; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Un-Ki; Yang, Yi; Yanush, Serguei; Yao, Liwen; Yao, Weiming; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yen, Andy L; Yildirim, Eda; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zaytsev, Alexander; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Lei; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Lei; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Zinonos, Zinonas; Ziolkowski, Michael; Zitoun, Robert; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zutshi, Vishnu; Zwalinski, Lukasz

    2014-01-01

    The liquid argon calorimeter is a key component of the ATLAS detector installed at the CERN Large Hadron Collider. The primary purpose of this calorimeter is the measurement of electrons and photons. It also provides a crucial input for measuring jets and missing transverse momentum. An advanced data monitoring procedure was designed to quickly identify issues that would affect detector performance and ensure that only the best quality data are used for physics analysis. This article presents the validation procedure developed during the 2011 and 2012 LHC data-taking periods, in which more than 98% of the proton–proton luminosity recorded by ATLAS at a centre-of-mass energy of 7–8 TeV had calorimeter data quality suitable for physics analysis.

  15. The status of the construction and the performance of the ATLAS liquid argon electromagnetic calorimeters

    CERN Document Server

    Lund-Jensen, B

    2004-01-01

    The construction of the ATLAS liquid argon electromagnetic calorimeters is about to be completed The barrel calorimeter and the first end cap are inserted in their cryostats. The quality control performed during the production has resulted in only a very small fraction of malfunctioning channels, ~0.1 %o., and a low constant term in the energy resolution. Several modules of the calorimeter and their corresponding presampler sectors have been tested in electron beams and their energy resolution has been shown to be within the ATLAS requirements. The local constant term is better than 0.4% for all measured cells and the global constant term which includes the cell to cell response variation is less than 0.7%. (3 refs).

  16. The ATLAS liquid argon calorimeter high-voltage system: commissioning, optimisation and LHC relative luminosity measurement

    International Nuclear Information System (INIS)

    The main goals of the ATLAS scientific programme are the observation or exclusion of physics beyond the Standard Model (SM), as well as the measurement of production cross-sections of SM processes. In order to do so, it is important to measure the luminosity at the interaction point with great precision. The ATLAS luminosity is extracted using several detectors with varying efficiencies and acceptances. Different methods, such as inclusive - or coincidence - event counting and calorimeter integrated current measurements, are calibrated and cross-compared to provide the most accurate luminosity determination. In order to provide more cross-checks and a better control on the systematic uncertainties, an independent measurement using the liquid argon (LAr) forward calorimeter (FCal), based on the readout current of its high-voltage system, has been developed. This document describes how the LAr calorimeter high-voltage system has been installed and commissioned, as well as its application to a relative luminosity determination. (author)

  17. Upgrade of the Trigger System of the ATLAS Liquid Argon calorimeters

    CERN Document Server

    Kanaya, N; The ATLAS collaboration

    2014-01-01

    The ATLAS detector was designed and build to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm^-2s^-1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |η| <3.2, and for hadronic calorimetry in the region from |η| = 1.5 to |η| = 4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals, which are digitized and processed by the front-end and back-end electronics for each triggered event. In addition, the front-end electronics sums analog signals to provide coarse-grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2019, instantaneous luminosities of (2-3)×1034 cm^-2s^-1 are expected, far beyond that for which the detector was designed. In order to cope with this increased trigger rate, an improved spatial granularity of the trigger primitives is pro...

  18. Upgrade of the Trigger System of the ATLAS Liquid Argon calorimeters

    CERN Document Server

    Kanaya, N; The ATLAS collaboration

    2014-01-01

    ATLAS detector was designed and build to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm-2s-1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |η| <3.2, and for hadronic calorimetry in the region from |η| = 1.5 to |η| = 4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals, which are digitized and processed by the front-end and back-end electronics for each triggered event. In addition, the front-end electronics sums analog signals to provide coarse-grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2020, instantaneous luminosities of (2-3)×1034 cm-2s-1 are expected, far beyond that for which the detector was designed. In order to cope with this increased trigger rate, an improved spatial granularity of the trigger primitives is proposed, t...

  19. Electronic Readout of the Atlas Liquid Argon Calorimeter: Calibration and Performance

    CERN Document Server

    Majewski, S; The ATLAS collaboration

    2010-01-01

    The Liquid Argon (LAr) calorimeter is a key detector component in the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. The LHC is a proton-proton collider with a center-of-mass energy of 14 TeV. The machine has been operated at energies of 900 GeV and 2.36 TeV in 2009 and is expected to reach the energy of 7 TeV in 2010. The LAr calorimeter is designed to provide precision measurements of electrons, photons, jets and missing transverse energy. It consists of a set of sampling calorimeters with liquid argon as active medium kept into three separate cryostats. The LAr calorimeters are read out via a system of custom electronics. The electronic readout of the ATLAS LAr calorimeters is divided into a Front End (FE) system of boards mounted in custom crates directly on the cryostat feedthroughs, and a Back End (BE) system of VME-based boards located in an off-detector underground counting room where there is no radiation. The FE system includes Front End boards (FEBs), which perform the readout and dig...

  20. Upgrade of the Trigger Readout System of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Marino, CP; The ATLAS collaboration

    2013-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 10^34 cm^-2 s^-1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |eta|<3.2, and for hadronic calorimetry in the region from |eta|=1.5 to |eta|=4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitizedand processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics sums analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2018, an instantaneous luminosity of 2-3 x 10^34 cm^-2 s^-1 is expected, far beyond the nominal one for which the detector was designed. In order to cope with this increased trigger rate, an improved spatial granularity of the trigger primi...

  1. Upgrade of the Trigger Readout System of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Marino, CP; The ATLAS collaboration

    2014-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34} \\rm{cm}^{-2} \\rm{s}^{-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\\eta|$ < 3.2, and for hadronic calorimetry in the region from $|\\eta|=$1.5 to $|\\eta|=$4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics sums analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2018, an instantaneous luminosity of 2-3 $\\times 10^{34} \\rm{cm}^{-2} \\rm{s}^{-1}$ is expected, far beyond the nominal one for which the detector was designed. In order to cope with this increased trigger rate,...

  2. The monitoring and data quality assessment of the ATLAS liquid argon calorimeter

    CERN Document Server

    Simard, O; The ATLAS collaboration

    2014-01-01

    The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider (LHC) at CERN. Liquid argon (LAr) sampling calorimeters are used for all electromagnetic calorimetry in the pseudo-rapidity region |η|< 3.2, as well as for hadronic calorimetry in the range 1.5<|η|<4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform response without azimuthal gaps. Copper and tungsten were chosen as passive material for the hadronic calorimetry; while a classic parallel-plate geometry was adopted at large polar angles, an innovative design based on cylindrical electrodes with thin liquid argon gaps is employed for the coverage at low angles, where the particle flux is higher. All detectors are housed in three cryostats maintained at about 88.5K. The approximately 200K cells are read out via front-end boards housed in on-detector crates that also contain monitoring, calibration, trigg...

  3. The monitoring and data quality assessment of the ATLAS liquid argon calorimeter

    CERN Document Server

    Simard, O

    2014-01-01

    The ATLAS experiment is designed to study the proton-proton ($pp$) collisions produced at the Large Hadron Collider (LHC) at CERN. Liquid argon (LAr) sampling calorimeters are used for all electromagnetic calorimetry in the pseudo-rapidity region $|\\eta|< 3.2$, as well as for hadronic calorimetry in the range $1.5 < |\\eta| < 4.9$. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform response without azimuthal gaps. Copper and tungsten were chosen as passive material for the hadronic calorimetry; while a classic parallel-plate geometry was adopted at large polar angles, an innovative design based on cylindrical electrodes with thin liquid argon gaps is employed at low angles, where the particle flux is higher. All detectors are housed in three cryostats maintained at about 88.5~K. The 182,468 cells are read out via front-end boards housed in on-detector crates that also contain monitoring, calibration, trigger and t...

  4. ATLAS Liquid Argon Calorimeter Performance in Run 1 and Run 2

    CERN Document Server

    Kuwertz, Emma Sian; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}$ cm$^{−2}$ s$^{−1}$ . Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region $\\eta < 3.2$, and for hadronic calorimetry in the region from $\\eta = 1.5$ to $\\eta = 4.9$. In the first LHC run a total luminosity of $27$ fb$^{−1}$ has been collected at center-of-mass energies of 7-8 TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately $3.9$ fb$^{-1}$ of data at a center-of-mass energy of 13 TeV recorded in this year. The well calibrated and highly granular Liquid Argon Calorimeter achieved its design values both in energy measurement as well as in direction resolution, which was a main ingredient for the successful discovery of a Higgs boson in the di-photon decay channel. This contribution will give ...

  5. Development of ATLAS Liquid Argon Calorimeters Readout Electronics for HL-LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00388354; The ATLAS collaboration

    2016-01-01

    The high-luminosity phase of the Large Hadron Collider (LHC) will provide 5-7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters and their readout system. The improved trigger system has a higher acceptance rate of 1 MHz and a longer latency of up to 60 micro-seconds. This requires an upgrade of the readout electronics, a better radiation tolerance is also required. This paper will present concepts for the future readout of the 182,468 calorimeter channels at 40 or 80 MHz with a 16 bit dynamic range. Progress of the development of low-noise, low-power and high-bandwidth electronic components will be presented. These include radiation-tolerant preamplifiers, analog-to-digital converters (ADC) up to 14 bits and low-power optical links providing transfer rates of at least 10 Gbps per fiber.

  6. Development of ATLAS Liquid Argon Calorimeters Readout Electronics for HL-LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00388354; The ATLAS collaboration

    2016-01-01

    The high-luminosity phase of the Large Hadron Collider will provide 5-7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon Calorimeters and their readout system. An improved trigger system with a higher acceptance rate of 1 MHz and a longer latency of up to 60 micro-seconds together with a better radiation tolerance require an upgrade of the readout electronics. Concepts for the future readout of the 182,500 calorimeter channels at 40/80 MHz and 16 bit dynamic range, and the development of low-noise, low-power and high-bandwidth electronic components will be presented. These include ASIC developments towards radiation-tolerant low-noise pre-amplifiers, analog-to-digital converters up to 14 bits and low-power optical links providing transfer rates of at least 10 Gb/s per fiber.

  7. The monitoring and data quality assessment of the ATLAS liquid argon calorimeter

    International Nuclear Information System (INIS)

    The ATLAS experiment is designed to study the proton-proton (pp) collisions produced at the Large Hadron Collider (LHC) at CERN. Liquid argon (LAr) sampling calorimeters are used for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2, as well as for hadronic calorimetry in the range 1.5 < |η| < 4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform response without azimuthal gaps. Copper and tungsten were chosen as passive material for the hadronic calorimetry; while a classic parallel-plate geometry was adopted at large polar angles, an innovative design based on cylindrical electrodes with thin liquid argon gaps is employed at low angles, where the particle flux is higher. All detectors are housed in three cryostats maintained at about 88.5 K. The 182,468 cells are read out via front-end boards housed in on-detector crates that also contain monitoring, calibration, trigger and timing boards. In the first three years of LHC operation, approximately 27 fb−1 of pp collision data were collected at centre-of-mass energies of 7-8 TeV. Throughout this period, the calorimeter consistently operated with performances very close to specifications, with high data-taking efficiency. This is in large part due to a sophisticated data monitoring procedure designed to quickly identify issues that would degrade the detector performance, to ensure that only the best quality data are used for physics analysis. After a description of the detector design, main characteristics and operation principles, this paper details the data quality assessment procedures developed during the 2011 and 2012 LHC data-taking periods, when more than 98% of the luminosity recorded by ATLAS had high quality LAr calorimeter data suitable for physics analysis

  8. Status of the Atlas Liquid Argon Calorimeter and its Performance after two years of LHC operation

    CERN Document Server

    AperioBella, L; The ATLAS collaboration

    2012-01-01

    The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo-rapidity region up to 3.2, as well as for hadronic calorimetry. The most forward part (pseudo-rapidity region 3.1-4.9) contains a electromagnetic section and two hadronic wheels. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at 87 K. After installation in 2004-2006, the calorimeters were extensively commissioned over t...

  9. Signal Processing for the ATLAS Liquid Argon Calorimeter : studies and implementation

    CERN Document Server

    Oliveira Damazio, D; The ATLAS collaboration

    2013-01-01

    The ATLAS detector operated successfully in the LHC studying the pp collisions produced with an energy up to 8 TeV in the center of mass. During the period from 2009 to 2012, called the LHC Run 1, up to more than 36 independent collisions were produced every 50 ns at the LHC. The ATLAS detector has a set of calorimeters measuring the energy of different types of particles. The liquid argon calorimeters work by ionization of their active material and the free electrons are collected by electrodes at high voltages. The generated current signal has a well known pulse shape. Multiple samples of the analog signal are collected and digital signal processing techniques are used to extract its amplitude which is related to the energy deposited. The signal pulse is relatively long (up to 400 ns) and the probability of background events happening in the same detector area during that interval is high. A technique called optimal filtering is used to minimize the effects of such pile-up. In the next data taking period, t...

  10. Measurement of heat-flow for the ATLAS liquid-argon FCal under HL-LHC conditions

    International Nuclear Information System (INIS)

    The ATLAS Forward Calorimeter (FCal) is a sampling calorimeter made of copper and tungsten with liquid argon as active medium. In the high luminosity phase of the LHC (HL-LHC) the luminosity will be increased up to 7 . 1034 cm-2 s-1. Under these conditions, the high energy density in the FCal may lead to formation of bubbles in the liquid argon, which would prevent a safe operation of the FCal. The main resistance for the heat transport away from the FCal is a small gap between the FCal and the Hadronic Endcap Calorimeter (HEC) filled with liquid argon. A simulation of the heat-flow shows large systematic uncertainties. Therefore, a mock-up of this detector area has been built to determine the heat-flow across this gap experimentally. Measurement results from the FCal test setup are reported, which indicate if the FCal can be safely operated at the HL-LHC.

  11. Search for Technihadrons in Dielectron channel and alignments of the ATLAS liquid Argon Electromagnetic calorimeters

    International Nuclear Information System (INIS)

    The LHC campaign in the first years of data taking was successful. The 2011 run has allowed to record more than 5 fb-1 of data at √(s) = 7 TeV with the ATLAS experiment. In the work presented in this this thesis the whole 2011 data set is used to performed different studies. This thesis is organized in five chapters. In the first chapter is presented a theoretical introduction to the Standard Model (SM) and to one of its possible extension the TechniColor model (TC). The second chapter gives an overview of the LHC complex and of the ATLAS detector components. In the third chapter the timing analysis on all the readout channels of the Liquid Argon Calorimeter is reported. A precise timing alignment over the whole calorimeter is used to synchronize the detector readout system with the LHC bunch crossing and has also application in some physics analysis such as those looking for long lived particles. In the searches for new phenomena an excellent electron identification capability, with high efficiency and high jet rejection rate, is required over a broad energy range. The fourth chapter of this thesis presents the measurements of the trigger and the identification electron efficiency using Z → ee events. Finally the last chapter describes a search for resonant deviations from the Standard Model in the high masses of the dielectron spectrum within two different Technicolor scenarios the Low-scale Technicolor and the Minimal Walking Technicolor. The significance of potential excess of the TC candidate events over the SM background expectation is evaluated in the dilepton invariant mass distribution. In the absence of any significant signal 95% confidence level limits are set on the cross section and on the resonance mass. (author)

  12. Upgrade readout and trigger electronics for the ATLAS liquid argon calorimeters for future LHC running

    CERN Document Server

    Yamanaka, T; The ATLAS collaboration

    2014-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that must be digitized and processed by the front-end and back-end electronics at every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first-level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34 cm^-2s^-1. However, in future higher-luminosity phases of LHC operation, the luminosity (and associated pile-up noise) will be 3-7 times higher. An improved spatial granularity of the trigger primitives is therefore proposed, in order to improve the trigger performance at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards are being designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new digital processing system (DPS). This applies digital filtering and identifies significant energy depositions in each trigger ch...

  13. Upgraded readout and trigger electronics for the ATLAS liquid argon calorimeters for future LHC running

    CERN Document Server

    Yamanaka, T; The ATLAS collaboration

    2014-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that must be digitized and processed by the front-end and back-end electronics at every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first-level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34 cm^-2s^-1. However, in future higher-luminosity phases of LHC operation, the luminosity (and associated pile-up noise) will be 3-7 times higher. An improved spatial granularity of the trigger primitives is therefore proposed, in order to improve the trigger performance at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards are being designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new digital processing system (DPS). This applies digital filtering and identifies significant energy depositions in each trigger ch...

  14. Upgraded readout and trigger electronics for the ATLAS liquid argon calorimeters for future LHC running

    CERN Document Server

    Ma, Hong; The ATLAS collaboration

    2014-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that must be digitized and processed by the front-end and back-end electronics for every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first-level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34/cm^2/s. However, in future higher-luminosity phases of LHC operation, the luminosity (and associated pile-up noise) will be 3-7 times higher. An improved spatial granularity of the trigger primitives is therefore proposed, in order to improve the trigger performance at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards are being designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new digital processing system (DPS). This applies digital filtering and identifies significant energy depositions in each trigger chan...

  15. Electronics Development for the ATLAS Liquid Argon Calorimeter Trigger and Readout for Future LHC Running

    CERN Document Server

    Hopkins, Walter; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will provide 7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019-2020, a trigger readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024-2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energies of a...

  16. Electronics Development for the ATLAS Liquid ArgonCalorimeter Trigger and Readout for Future LHC Running

    CERN Document Server

    Hopkins, Walter; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will provide 7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019-2020, a trigger readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024-2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energies of a...

  17. The ATLAS liquid argon calorimeter: upgrade plans for the HL-LHC

    International Nuclear Information System (INIS)

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm−2s−1. Liquid argon (LAr) sampling calorimeters are employed for electromagnetic and hadronic calorimetry. The luminosity for the proposed High Luminosity LHC phase (HL-LHC) will increase up to 5×1034 cm−2s−1 with the goal of accumulating an integrated luminosity of 3000 fb−1. This is well beyond the values for which the detectors were designed. The electromagnetic and hadronic calorimeters will be able to tolerate the increased particle flux, but the performance of the forward calorimeter (FCal) will be affected. Two possible solutions for keeping the current performance are being discussed. The readout electronics will also need to withstand larger radiation environment. In the hadronic endcap calorimeter (HEC) cold GaAs preamplifiers are located inside the endcap cryostats. The properties of these devices have been investigated in recent proton and neutron irradiation tests to determine whether they must be replaced. In addition, the entire front-end readout system is not expected to survive the integrated luminosity at the HL-LHC and will be replaced. The description of the new readout system is presented

  18. Electronics Development for the ATLAS Liquid Argon Calorimeter - Trigger and Readout for Future LHC Running -

    CERN Document Server

    Starz, Steffen; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will provide up to 7.5 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019-2020, a trigger-readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024-2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energ...

  19. Performance of the ATLAS Liquid Argon Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    Benitez, Jose; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}$ cm$^{-2}$ s${^-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\\eta|<3.2$, and for hadronic calorimetry in the region from $|\\eta|=1.5$ to $|\\eta|=4.9$. The calibration and performance of the LAr calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb$^{-1}$ of data have been collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~fb$^{-1}$ of data at a center-of-mass energy of 13~TeV recorded in this year. Results on the LAr calorimeter operation, monitoring and data quality, as we...

  20. The ATLAS liquid argon calorimeter: upgrade plans for the HL-LHC

    CERN Document Server

    Novgorodova, O; The ATLAS collaboration

    2014-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034cm-2s-1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |η|<3.2, and for hadronic calorimetry in the region from |η|=1.5 to |η|=4.9. Although the nominal LHC experimental programme is still in progress, plans for a High Luminosity LHC (HL-LHC) are already being developed for operation of the collider and associated detectors at luminosities of up to (5-7)×1034 cm-2s-1, with the goal of accumulating an integrated luminosity of 3000 fb-1. The proposed instantaneous and integrated luminosities are both well beyond the values for which the detectors were designed. The electromagnetic and hadronic calorimeters will be able to tolerate the increased particle flux, but the performance of the forward calorimeter (FCal) will be affected. Two solutions for this are un...

  1. FPGA-based 10-Gbit Ethernet data acquisition interface for the upgraded electronics of the ATLAS liquid argon calorimeters

    International Nuclear Information System (INIS)

    A stepwise upgrade of the LHC is foreseen starting now until the year 2023 to increase the instantaneous luminosity up to five times of its design value. It implies a challenge for the ATLAS experiment coping with the expected event pile-up, especially for the Level-1 calorimeter trigger system. In order to keep the trigger rates within the limited bandwidth new algorithms have to be applied which in turn requires an upgrade of the ATLAS Liquid Argon calorimeter trigger readout electronics. Towards this upgrade, the ATLAS Liquid Argon calorimeter group develops a high-speed data acquisition interface in ATCA standard using commercial hardware instead of complex and expensive in-house developments where possible. This paper gives an overview of the general concepts of the DAQ interface, the engaged technologies and the current status of the development efforts for an FPGA based fast data link with a standard 10 Gbps Ethernet protocol which may also be useful for DAQ systems of other high energy physics experiments.

  2. Irradiation tests of ATLAS liquid argon forward calorimeter (FCAL) electronics components

    CERN Document Server

    Leroy, C; Golikov, V; Golubyh, S M; Kukhtin, V; Kulagin, E; Luschikov, V; Merkulov, L; Minashkin, V F; Shalyugin, A N

    2002-01-01

    FCAL resistors, capacitors, and transformers together with capacitors and sintimid disks of the purity monitor have been irradiated in liquid argon to study their possible lead to argon pollution at a maximal neutron fluence of 1016 n cm-2 at the IBR-2 reactor of JINR, Dubna. The results of charge collection measurements before and after irradiation are reported. Electrical measurement on these FCAL capacitors, resistors and transformers were also performed after irradiation. In general, the results of resistance, capacitance, impedance, leakage current and high voltage breakdown measurements after irradiation show minor changes of value only for some parameters from nominal values or values measured before irradiation.

  3. Development of Digital Signal Processing with FPGAs for the Readout of the ATLAS Liquid Argon Calorimeter at HL-LHC

    CERN Document Server

    Stärz, Steffen; Zuber, K

    2010-01-01

    The Liquid Argon calorimeter of the ATLAS detector at CERN in Geneva is supposed to be equipped with advanced readout electronics for the operation at High Luminosity LHC. In this diploma thesis the aspect of fast serial data transmission and data processing to be used for the communication between different readout modules and data storage buffers of the trigger shall be further developed. Furthermore, the main focus is put on first preparation of the detector raw data with regard to a signal correction using a FIR filter. It is aimed at a most efficient, most resource economising and minimal latency causing solution that allows to process the huge amount of upcoming detector raw data in real time. Therefore a via UDP/IP reconfigurable prototype of a 5-stage FIR filter with Gigabit Ethernet Interface was implemented in a Xilinx Virtex-5 FPGA. The performance reached is fully within the the requirements for the upgraded calorimeter readout of ATLAS.

  4. Radiation Tolerant Electronics and Digital Processing for the Phase-1 Readout Upgrade of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Milic, Adriana; The ATLAS collaboration

    2015-01-01

    The high luminosities of $L > 10^{34} cm^{-2} s^{-1}$ at the Large Hadron Collider (LHC) at CERN produce an intense radiation environment that the detectors and their electronics must withstand. The ATLAS detector is a multi-purpose apparatus constructed to explore the new particle physics regime opened by the LHC. Of the many decay particles observed by the ATLAS detector, the energy of the created electrons and photons is measured by a sampling calorimeter technique that uses Liquid Argon (LAr) as its active medium. The front end (FE) electronic readout of the ATLAS LAr calorimeter located on the detector itself consists of a combined analog and digital processing system. In order to exploit the higher luminosity while keeping the same trigger bandwidth of 100 kHz, higher transverse granularity, higher resolution and longitudinal shower shape information will be provided from the LAr calorimeter to the Level-1 trigger processors. New trigger readout electronics have been designed for this purpose, which wil...

  5. Radiation Tolerant Electronics and Digital Processing for the Phase-I Trigger Readout Upgrade of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Milic, Adriana; The ATLAS collaboration

    2015-01-01

    The high luminosities of $\\mathcal{L} > 10^{34} \\mathrm{cm}^{-2} \\mathrm{s}^{-1}$at the Large Hadron Collider (LHC) at CERN produce an intense radiation environment that the detectors and their electronics must withstand. The ATLAS detector is a multi-purpose apparatus constructed to explore the new particle physics regime opened by the LHC. Of the many decay particles observed by the ATLAS detector, the energy of the created electrons and photons is measured by a sampling calorimeter technique that uses Liquid Argon (LAr) as its active medium. The Front End (FE) electronic readout of the ATLAS LAr calorimeter located on the detector itself consists of a combined analog and digital processing system. The FE electronics were qualified for radiation levels corresponding to 10 years of LHC operations. The high luminosity running of the LHC (HL-LHC), with instantaneous luminosities of $5 \\times 10^{34} \\mathrm{cm}^ {-2} \\mathrm{s}^{-1}$ and an integrated luminosity of $3000 \\ \\mathrm{fb}^{-1}$ will exceed these d...

  6. A linear low power remote preamplifier for the atlas liquid argon em calorimeter

    International Nuclear Information System (INIS)

    In a previous paper, it was shown that, for shaping times of the order of the transmission line delay, a remote, external Preamplifier could perform as well as one connected directly to a liquid argon calorimeter. Here we describe an improved circuit configuration where, by attributing the functions of low noise and high dynamic range to two different transistors, the linearity can be improved and the noise can be decreased while reducing the power dissipation by a factor of three (to about 40 mW). The gain (i.e., the transresistance) and the input impedance can be chosen independently without changing the power supply voltages and power dissipation

  7. Installation of the Liquid Argon Calorimater Barrel in the ATLAS Experimental Cavern

    CERN Multimedia

    Vandoni, G.

    On the 27th of October, the Liquid Argon Barrel cryostat was transported from Building 180 to point 1. The next day, the Barrel was lowered into the cavern, and was placed on jacks close to its final position inside the completed lower half of the Tile calorimeter. After a day of precise adjustment, it was resting within a few millimetres of its nominal final position, waiting for the upper half of the Tile calorimeter to be installed. Tight requests had been issued by the Liquid Argon collaboration for the whole transport. It was foreseen that the cryostat should not see any acceleration larger than 0.15g along its axis, 0.08g transversally and 0.3g in the vertical direction. In addition, no acceleration higher than 0.03g (or even 0.003g for permanent oscillation) would be allowed at 20Hz, to avoid the risk of damaging the absorbers at this spontaneous vibration frequency. The difficulty would arise when coping these demands with the tortuous route, its slopes and curbs, vibration transmission from the engi...

  8. Liquid Argon Barrel Cryostat Arrived

    CERN Multimedia

    Pailler, P

    Last week the first of three cryostats for the ATLAS liquid argon calorimeter arrived at CERN. It had travelled for 46 days over several thousand kilometers from Japan to CERN. During three years it has been fabricated by Kawasaki Heavy Industries Ltd. at Harima, close to Kobe, under contract from Brookhaven National Laboratory (BNL) of the U.S.. This cryostat consists of two concentric cylinders made of aluminium: the outer vacuum vessel with a diameter of 5.5 m and a length of 7 m, and the inner cold vessel which will contain the electromagnetic barrel calorimeter immersed in liquid argon. The total weight will be 270 tons including the detectors and the liquid argon. The cryostat is now located in building 180 where it will be equipped with 64 feed-throughs which serve for the passage of 122,880 electrical lines which will carry the signals of the calorimeter. After integration of the calorimeter, the solenoidal magnet of ATLAS will be integrated in the vacuum vessel. A final cold test of the cryostat inc...

  9. Development of the Trigger Readout System for the Phase-I Upgrade of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Xu, Hao; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and at instantaneous luminosities up to 1034cm-2s-1. An LHC upgrade is planned to enhance the luminosities to 2-3 x 1034cm-2s-1 and to deliver an integrated luminosity of about 300 fb-1 during Run 3 from 2019 through 2021. In order to improve the identification performance for electrons, photons, taus, jets, missing energy at high background rejection rates, an improved spatial granularity of the trigger primitives has been proposed. Therefore, a new trigger readout system is being designed to digitize and process the signals with higher spatial granularity. A demonstrator system has been developed and installed on the ATLAS detector to evaluate the technical and performance aspects. Analog signal parameters including noise and cross-talk have been analyzed. The performance of the new demonstrator system in the ...

  10. Development of the Trigger Readout System for Phase-I Upgrade of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Xu, Hao; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and at instantaneous luminosities up to 10^34 cm^-2s^-1. An LHC upgrade is planned to enhance the luminosities to 2-3 x 10^34 cm^-2 s^-1 and to deliver an integrated luminosity of about 300 fb^-1 during Run 3 from 2019 through 2021. In order to improve the identification performance for electrons, photons, taus, jets, missing energy at high background rejection rates, an improved spatial granularity of the trigger primitives has been proposed. Therefore, a new trigger readout system is being designed to digitize and process the signals with higher spatial granularity. A demonstrator system has been developed and installed on the ATLAS detector to evaluate the technical and performance aspects. Analog signal parameters including noise and cross-talk have been analyzed. The performance of the new readout system is...

  11. Simulation of the upgraded Phase-1 Trigger Readout Electronics of the Liquid-Argon Calorimeter of the ATLAS Detector at the LHC

    OpenAIRE

    Grohs, Johannes Philipp

    2016-01-01

    In the context of an intensive upgrade plan for the Large Hadron Collider (LHC) in order to provide proton beams of increased luminosity, a revision of the data readout electronics of the Liquid-Argon-Calorimeter of the ATLAS detector is scheduled. This is required to retain the efficiency of the trigger at increased event rates despite its fixed bandwidth. The focus lies on the early digitization and finer segmentation of the data provided to the trigger. Furthermore, there is the possibilit...

  12. Upgraded Readout and Trigger Electronics for the ATLAS Liquid Argon Calorimeter at the LHC at the Horizons 2018-2022

    CERN Document Server

    Oliveira Damazio, Denis; The ATLAS collaboration

    2013-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics is summing analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up noise expected during the High Luminosity phases of LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons, photons, tau leptons, jets, total and missing energy, at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Board (LTDB) are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new digital processing system (DPS). The DPS applies...

  13. Study of the response of ATLAS electromagnetic liquid argon calorimeters to muons

    CERN Document Server

    Aharrouche, M; Di Ciaccio, L; El Kacimi, M; Gaumer, O; Gouanère, M; Goujdami, D; Lafaye, R; Laplace, S; Le Maner, C; Neukermans, L; Perrodo, P; Poggioli, L; Prieur, D; Przysiezniak, H; Sauvage, G; Wingerter-Seez, I; Zitoun, R; Lanni, F; Ma, H; Rajagopalan, S; Rescia, S; Takai, H; Belymam, A; Benchekroun, D; Hakimi, M; Hoummada, A; Gao, Y; Lu, L; Stroynowski, R; Aleksa, M; Carli, T; Fassnacht, P; Gianotti, F; Hervas, L; Lampl, W; Collot, J; Hostachy, J Y; Ledroit-Guillon, F; Malek, F; Martin, P; Viret, S; Leltchouk, M; Parsons, J A; Simion, S; Barreiro, F; Del Peso, J; Labarga, L; Oliver, C; Rodier, S; Barrillon, P; Djama, F; Hubaut, F; Mangeard, P S; Monnier, E; Niess, V; Pralavorio, P; Resende, B; Sauvage, D; Serfon, C; Tisserant, S; Toth, J; Zhang, H; Banfi, D; Carminati, L; Cavalli, D; Costa, G; Delmastro, M; Fanti, M; Mandelli, L; Mazzanti, M; Tartarelli, G F; Kotov, K; Maslennikov, A; Pospelov, G; Tikhonov, Yu; Bourdarios, C; Fayard, L; Fournier, D; Iconomidou-Fayard, L; Kado, M; Parrour, G; Plamondon, M; Puzo, P; Rousseau, D; Sacco, R; Serin, L; Unal, G; Zerwas, D; Dekhissi, B; Derkaoui, J; El Kharrim, A; Maaroufi, F; Cleland, W; Lacour, D; Laforge, B; Nikolic-Audit, I; Schwemling, Ph; Ghazlane, H; Cherkaoui El Moursli, R; Idrissi Fakhr-Eddine, A; Boonekamp, M; Mansoulié, B; Meyer, P; Schwindling, J; Lund-Jensen, B; Tayalati, Y

    2009-01-01

    The response of the ATLAS electromagnetic calorimeter to muons has been studied in this paper. Results on signal over noise ratio, assessment of the detector response uniformity, and position resolution are presented. The possibility to study fine details of the structure of the detector through its response to muons is illustrated on a specific example. Finally, the performance obtained on muons in test-beam is used to estimate the detector uniformity and time alignment precision that will be reachable after the commissioning of the ATLAS detector with cosmic rays.

  14. Monitoring and data quality assessment of the ATLAS liquid argon calorimeter

    Czech Academy of Sciences Publication Activity Database

    Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav

    2014-01-01

    Roč. 9, Jul (2014), s. 1-39. ISSN 1748-0221 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : missing-energy * data acquisition * ATLAS * CERN LHC Coll * monitoring performance Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.399, year: 2014

  15. Combined Intercalibration and Longitudinal Weight Extraction for the ATLAS Liquid-Argon EM Calorimeter

    CERN Document Server

    Paganis, S; Carli, T; Unal, G

    2004-01-01

    Two major problems for most physics analyses in ATLAS are: (i) the equalization of response of different physical regions of the electromagnetic (EM) Calorimeter (intercalibration), and (ii) the correction of upstream material effects in energy reconstruction through extraction of the EM longitudinal weights. A possible solution to these problems consists of the in-situ calibration of the calorimeter using electrons from W$^\\pm$ or Z$^0$-boson decays. When electrons are used, intercalibration depends on longitudinal weights and vice versa, making it very hard to decouple the two effects in-situ. In this note we report on the development of a combined minimization method that provides simultaneous intercalibration and longitudinal weight extraction and can be used during the ATLAS data taking. It is shown that an intercalibration at the $\\simeq$2ppm level, including upstream material effects and excluding the crack region, can be achieved under realistic conditions. A small degradation of the energy resolution...

  16. Phase-I Trigger Readout Electronics Upgrade of the ATLAS Liquid-Argon Calorimeters

    CERN Document Server

    Mori, Tatsuya; The ATLAS collaboration

    2015-01-01

    This document for NEC’2015 proceedings gives an overview of the Phase-I Upgrade on the ATLAS LAr Calorimeter Trigger Readout. The design of custom developed hardware for fast real-time data processing and transfer is also overviewed. Performance results from the prototype boards in the demonstrator system are shown. First measurements of noise levels and linearity on response from the demonstrator system are shown.

  17. RT2016 Phase-I Trigger Readout Electronics Upgrade for the ATLAS Liquid-Argon Calorimeters

    CERN Document Server

    AUTHOR|(SzGeCERN)478829; The ATLAS collaboration

    2016-01-01

    For the Phase-I luminosity upgrade of the LHC, a higher granularity trigger readout of the ATLAS LAr Calorimeters is foreseen in order to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, which are grouped into 34000 so-called Super Cells, with 12-bit precision at 40 MHz. The data is transferred via optical links to a digital processing system which extracts the Super Cell energies. A demonstrator version of the complete system has now been installed and operated on the ATLAS detector. The talk will give an overview of the Phase-I Upgrade of the ATLAS LAr Calorimeter readout and present the custom developed hardware including their role in real-time data processing and fast data transfer. This contribution will also report on the performance of the newly developed ASICs including their radiation tolerance and on the performance of the prototype boards in the demonstrator system based on various measurements with the 13 TeV collision data. R...

  18. Phase-I Trigger Readout Electronics Upgrade of the ATLAS Liquid-Argon Calorimeters

    CERN Document Server

    Mori, Tatsuya; The ATLAS collaboration

    2015-01-01

    The Large Hadron Collider (LHC) is foreseen to be upgraded during the shut-down period of 2018-2019 to deliver about 3 times the instantaneous design luminosity. Since the ATLAS trigger system, at that time, will not support such an increase of the trigger rate an improvement of the trigger system is required. The ATLAS LAr Calorimeter readout will therefore be modified and digital trigger signals with a higher spatial granularity will be provided to the trigger. The new trigger signals will be arranged in 34000 Super Cells which achieves a 5-10 better granularity than the trigger towers currently used and allows an improved background rejection. The Super Cell readout is composed of custom developed 12-bit combined SAR ADCs in 130 nm CMOS technology which will be installed on-detector in a radiation environment and digitizes the detector pulses at 40 MHz. The data will be transmitted to the back end using a custom serializer and optical converter applying 5.44 Gb/s optical links. These components are install...

  19. Liquid argon neutrino detectors

    CERN Document Server

    Battistoni, G

    2001-01-01

    The liquid argon imaging technique, as proposed for the ICARUS detector, offers the possibility to perform complementary and simultaneous measurements of neutrinos, as those of CERN to Gran Sasso beam (CNGS) and those from cosmic ray events. For the currently allowed values of the Super-Kamiokande results, the combination of both CNGS and atmospheric data will provide a precise determination of the oscillation parameters. Since one can observe and unambiguously identify nu /sub e/, nu /sub mu / and nu /sub tau / components, this technology allows to explore the full (3*3) mixing matrix. The same class of detector can be proposed for high precision measurements at a neutrino factory. (3 refs).

  20. The Liquid Argon Purity Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Adamowski, M.; Carls, B.; Dvorak, E.; Hahn, A.; Jaskierny, W.; Johnson, C.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Stancari, M.; Tope, T.; Voirin, E.; Yang, T.

    2014-07-01

    The Liquid Argon Purity Demonstrator was an R&D test stand designed to determine if electron drift lifetimes adequate for large neutrino detectors could be achieved without first evacuating the cryostat. We describe here the cryogenic system, its operations, and the apparatus used to determine the contaminant levels in the argon and to measure the electron drift lifetime. The liquid purity obtained by this system was facilitated by a gaseous argon purge. Additionally, gaseous impurities from the ullage were prevented from entering the liquid at the gas-liquid interface by condensing the gas and filtering the resulting liquid before returning to the cryostat. The measured electron drift lifetime in this test was greater than 6 ms, sustained over several periods of many weeks. Measurements of the temperature profile in the argon, to assess convective flow and boiling, were also made and are compared to simulation.

  1. The Liquid Argon Purity Demonstrator

    CERN Document Server

    Adamowski, M; Dvorak, E; Hahn, A; Jaskierny, W; Johnson, C; Jostlein, H; Kendziora, C; Lockwitz, S; Pahlka, B; Plunkett, R; Pordes, S; Rebel, B; Schmitt, R; Stancari, M; Tope, T; Voirin, E; Yang, T

    2014-01-01

    The Liquid Argon Purity Demonstrator was an R&D test stand designed to determine if electron drift lifetimes adequate for large neutrino detectors could be achieved without first evacuating the cryostat. We describe here the cryogenic system, its operations, and the apparatus used to determine the contaminant levels in the argon and to measure the electron drift lifetime. The liquid purity obtained by this system was facilitated by a gaseous argon purge. Additionally, gaseous impurities from the ullage were prevented from entering the liquid at the gas-liquid interface by condensing the gas and filtering the resulting liquid before returning to the cryostat. The measured electron drift lifetime in this test was greater than 6 ms, sustained over several periods of many weeks. Measurements of the temperature profile in the argon, to assess convective flow and boiling, were also made and are compared to simulation.

  2. Testing a liquid Argon calorimeter

    CERN Multimedia

    1976-01-01

    Physicists from Karlsruhe test a liquid argon calorimeter in the neutral beam b16 at the PS. The calorimeter was meant to supply some neutral particles identification at the Split-Field Magnet Facility for R416.

  3. Simulation of the upgraded Phase-1 Trigger Readout Electronics of the Liquid-Argon Calorimeter of the ATLAS Detector at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00338138

    In the context of an intensive upgrade plan for the LHC in order to provide proton beams of increased luminosity, a revision of the data readout electronics of the Liquid-Argon-Calorimeter of the ATLAS detector is scheduled. This is required to retain the efficiency of the trigger at increased event rates despite its fixed bandwidth. The focus lies on the early digitization and finer segmentation of the data provided to the trigger. Furthermore, there is the possibility to implement new energy reconstruction algorithms which are adapted to the specific requirements of the trigger. In order to constitute crucial design decisions, such as the digitization scale or the choice of digital signal processing algorithms, comprehensive simulations are required. High trigger efficiencies are decisive at it for the successful continuation of the measurements of rare Standard Model processes as well as for a high sensitivity to new physics beyond the established theories. It can be shown that a significantly improved res...

  4. Energy Reconstruction and high-speed Data Transmission with FPGAs for the Upgrade of the ATLAS Liquid Argon Calorimeter at LHC

    CERN Document Server

    Stärz, Steffen

    The Liquid Argon calorimeter of the ATLAS detector at CERN near Geneva is equipped with improved readout and trigger electronics for the operation at higher luminosity LHC in the frame of several upgrades (Phase-0, I, and II). Special attention is given to an early digitisation of detector raw data and their following digital data transmission and processing via FPGAs already for the Level-1 trigger. The upgrades additionally foresee to provide higher spatial granularity information for the Level-1 trigger in order to improve its performance for low momentum single particles at increased collision rates. The first part of this dissertation contains the development and implementation of a modular detector simulation framework, AREUS, which allows to analyse different filter algorithms for the energy reconstruction as well as their performance with respect to the expected digitised detector raw data. In this detector simulation framework the detailed algorithmic functionality of the FPGAs has been taken into ac...

  5. Search for the Higgs boson through two photons decays with the Atlas detector at the LHC and calibration of the Liquid Argon calorimeter

    International Nuclear Information System (INIS)

    The physics program of the ATLAS experiment at the Large Hadron Collider (CERN) covers a wide area going from the search for a Standard Model Higgs boson to the search for new physics (supersymmetry, extra-dimensions...). This thesis focuses on two main axes: First, some studies on the liquid argon calorimeter electronics are presented. Studies related to the search for the Standard Model Higgs boson in the H →γγ decay channel (which is one of the most promising discovery channels in the low mass region, between the LEP limit mH > 144.4 GeV and 150 GeV) are also detailed. In particular the reconstruction of photons and the use of photons conversion into electron-positron pair are detailed. The aim of these studies is to increase the discovery potential of the Higgs boson. Aspects related to the validation of the fast simulation package of the ATLAS experiment are also discussed: The performances of the photon reconstruction (for both unconverted and converted photons) as well as the ability to reproduce full simulation results are emphasized. (author)

  6. Qualification procedure of the electromagnetic calorimeter of the ATLAS detector; Conception et mise au point de la procedure de qualification du calorimetre electromagnetique a argon liquide du detecteur ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Massol, N

    2000-04-19

    LHC is the next collider based at CERN in Europe. The purpose of this machine is the Higgs boson and SUSY particles search. The detectors must have an excellent electromagnetic calorimetry to measure electron and photon energy. To maximize the signal to noise ratio for a low mass Higgs, it is fundamental to obtain a constant term as small as possible. LAPP is participating in the construction of the liquid argon electromagnetic calorimeter of the ATLAS collaboration. This technology is well adapted to the LHC experimental conditions. A systematic procedure to qualify the modules of this detector is an essential step to guarantee a 0,7% constant term, which is the collaboration objective. The procedure detailed in this thesis consists of quality monitoring during mechanical assembly and of a set of electrical tests such as electrical continuity, cell and cross-talk capacitance measurement, and high-voltage behaviour. For the whole test, it has been necessary to develop dedicated electronic cards, to develop measurement methods, and the whole operation software. Making the procedure automatic will guarantee the quality of each module during assembly, cabling, and test in liquid argon. (author)

  7. Upgraded Readout and Trigger Electronics for the ATLAS Liquid-Argon Calorimeters at the LHC at the Horizons 2018-2022

    CERN Document Server

    Damazio, D O; The ATLAS collaboration

    2013-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics is summing analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up noise expected during the High Luminosity phases of LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons, photons, tau leptons, jets, total and missing energy, at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Board (LTDB) are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new digital processing system (DPS). The DPS applies...

  8. Pollution of liquid argon after neutron irradiation

    CERN Document Server

    Andrieux, M L; Collot, J; de Saintignon, P; Ferrari, A; Hostachy, J Y; Hoummada, A; Martin, P; Merkel, B; Puzo, P; Sauvage, D; Wielers, M

    2001-01-01

    The purpose of the neutron facility installed at SARA is to investigate the behavior of various materials to be used in the ATLAS liquid argon calorimeter, when submitted to fast neutron radiation. The samples are placed in a liquid argon cryostat a few cm away from the neutron source. Various pieces of the electromagnetic calorimeter have been tested in order to evaluate the rate of pollution of the liquid and consequently the possible signal loss in energy measurements. The average fluence was equivalent to the maximum expected in the calorimeter in about 10 years. The most striking feature of the results is that the pollution is not due to oxygen, at least for most of it. Using a particular value of the absorption length derived from these data, a simulation was carried out and the energy signal loss in the calorimeter could be predicted. Within the limits of our present knowledge, the conclusion is that damages due to this pollution will not be a problem. (17 refs).

  9. Pollution of liquid argon after neutron irradiation

    International Nuclear Information System (INIS)

    The purpose of the neutron facility installed at SARA is to investigate the behavior of various materials to be used in the ATLAS liquid argon calorimeter, when submitted to fast neutron radiation. The samples are placed in a liquid argon cryostat a few cm away from the neutron source. Various pieces of the electromagnetic calorimeter have been tested in order to evaluate the rate of pollution of the liquid and consequently the possible signal loss in energy measurements. The average fluence was equivalent to the maximum expected in the calorimeter in about 10 years. The most striking feature of the results is that the pollution is not due to oxygen, at least for most of it. Using a particular value of the absorption length derived from these data, a simulation was carried out and the energy signal loss in the calorimeter could be predicted. Within the limits of our present knowledge, the conclusion is that damages due to this pollution will not be a problem

  10. The scintillation of liquid argon

    CERN Document Server

    Heindl, T; Hofmann, M; Krücken, R; Oberauer, L; Potzel, W; Wieser, J; Ulrich, A

    2015-01-01

    A spectroscopic study of liquid argon from the vacuum ultraviolet at 110 nm to 1000 nm is presented. Excitation was performed using continuous and pulsed 12 keV electron beams. The emission is dominated by the analogue of the so called 2nd excimer continuum. Various additional emission features were found. The time structure of the light emission has been measured for a set of well defined wavelength positions. The results help to interpret literature data in the context of liquid rare gas detectors in which the wavelength information is lost due to the use of wavelength shifters.

  11. Photon reconstruction in the ATLAS Inner Detector and Liquid Argon Barrel Calorimeter at the 2004 Combined Test Beam

    International Nuclear Information System (INIS)

    The reconstruction of photons in the ATLAS detector is studied with data taken during the 2004 Combined Test Beam, where a full slice of the ATLAS detector was exposed to beams of particles of known energy at the CERN SPS. The results presented show significant differences in the longitudinal development of the electromagnetic shower between converted and unconverted photons as well as in the total measured energy. The potential to use the reconstructed converted photons as a means to precisely map the material of the tracker in front of the electromagnetic calorimeter is also considered. All results obtained are compared with a detailed Monte-Carlo simulation of the test-beam setup which is based on the same simulation and reconstruction tools as those used for the ATLAS detector itself.

  12. Photon reconstruction in the ATLAS Inner Detector and Liquid Argon Barrel Calorimeter at the 2004 Combined Test Beam

    CERN Document Server

    Abat, E; Addy, T N; Adragna, P; Aharrouche, M; Ahmad, A; Akesson, T.P A; Aleksa, M; Alexa, C; Anderson, K; Andreazza, A; Anghinolfi, F; Antonaki, A; Arabidze, G; Arik, E; Atkinson, T; Baines, J; Baker, O K; Banfi, D; Baron, S; Barr, A J; Beccherle, R; Beck, H P; Belhorma, B; Bell, P J; Benchekroun, D; Benjamin, D P; Benslama, K; Bergeaas Kuutmann, E; Bernabeu, J; Bertelsen, H; Binet, S; Biscarat, C; Boldea, V; Bondarenko, V G; Boonekamp, M; Bosman, M; Bourdarios, C; Broklova, Z; Burckhart-Chromek, D; Bychkov, V; Callahan, J; Calvet, D; Canneri, M; Capeans Garrido, M; Caprini, M; Cardiel Sas, L; Carli, T; Carminati, L; Carvalho, J; Cascella, M; Castillo, M V; Catinaccio, A; Cauz, D; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Cetin, S A; Chen, H; Cherkaoui, R; Chevalier, L; Chevallier, F; Chouridou, S; Ciobotaru, M; Citterio, M; Clark, A; Cleland, B; Cobal, M; Cogneras, E; Conde Muino, P; Consonni, M; Constantinescu, S; Cornelissen, T; Correard, S; Corso-Radu, A; Costa, G; Costa, M J; Costanzo, D; Cuneo, S; Cwetanski, P; Da Silva, D; Dam, M; Dameri, M; Danielsson, H O; Dannheim, D; Darbo, G; Davidek, T; De, K; Defay, P O; Dekhissi, B; Del Peso, J; Del Prete, T; Delmastro, M; Derue, F; Di Ciaccio, L; Di Girolamo, B; Dita, S; Dittus, F; Djama, F; Djobava, T; Dobos, D; Dobson, M; Dolgoshein, B A; Dotti, A; Drake, G; Drasal, Z; Dressnandt, N; Driouchi, C; Drohan, J; Ebenstein, W L; Eerola, P; Efthymiopoulos, I; Egorov, K; Eifert, T F; Einsweiler, K; El Kacimi, M; Elsing, M; Emelyanov, D; Escobar, C; Etienvre, A I; Fabich, A; Facius, K; Idrissi Fakhr-Eddine, A; Fanti, M; Farbin, A; Farthouat, P; Fassouliotis, D; Fayard, L; Febbraro, R; Fedin, O L; Fenyuk, A; Fergusson, D; Ferrari, P; Ferrari, R; Ferreira, B C; Ferrer, A; Ferrere, D; Filippini, G; Flick, T; Fournier, D; Francavilla, P; Francis, D; Froeschl, R; Froidevaux, D; Fullana, E; Gadomski, S; Gagliardi, G; Gagnon, P; Gallas, M; Gallop, B J; Gameiro, S; Gan, K K; Garcia, R; Garcia, C; Gavrilenko, I L; Gemme, C; Gerlach, P; Ghodbane, N; Giakoumopoulou, V; Giangiobbe, V; Giokaris, N; Glonti, G; Gottfert, T.; Golling, T; Gollub, N; Gomes, A; Gomez, M D; Gonzalez-Sevilla, S; Goodrick, M J; Gorfine, G; Gorini, B; Goujdami, D; Grahn, K J; Grenier, P; Grigalashvili, N; Grishkevich, Y; Grosse-Knetter, J; Gruwe, M; Guicheney, C; Gupta, A; Haeberli, C; Hartel, R.; Hajduk, Z; Hakobyan, H; Hance, M; Hansen, J D; Hansen, P H; Hara, K; Harvey, A., Jr; Hawkings, R J; Heinemann, F.E W; Henriques Correia, A; Henss, T; Hervas, L; Higon, E; Hill, J C; Hoffman, J; Hostachy, J Y; Hruska, I; Hubaut, F; Huegging, F; Hulsbergen, W; Hurwitz, M; Iconomidou-Fayard, L; Jansen, E; Jen-La Plante, I; Johansson, P.D C; Jon-And, K; Joos, M; Jorgensen, S; Joseph, J; Kaczmarska, A; Kado, M; Karyukhin, A; Kataoka, M; Kayumov, F; Kazarov, A; Keener, P T; Kekelidze, G D; Kerschen, N; Kersten, S; Khomich, A; Khoriauli, G; Khramov, E; Khristachev, A; Khubua, J; Kittelmann, T H; Klingenberg, R; Klinkby, E B; Kodys, P; Koffas, T; Kolos, S; Konovalov, S P; Konstantinidis, N; Kopikov, S; Korolkov, I; Kostyukhin, V; Kovalenko, S; Kowalski, T Z; Kruger, K.; Kramarenko, V; Kudin, L G; Kulchitsky, Y; Lacasta, C; Lafaye, R; Laforge, B; Lampl, W; Lanni, F; Laplace, S; Lari, T; Le Bihan, A C; Lechowski, M; Ledroit-Guillon, F; Lehmann, G; Leitner, R; Lelas, D; Lester, C G; Liang, Z; Lichard, P; Liebig, W; Lipniacka, A; Lokajicek, M; Louchard, L; Loureiro, K F; Lucotte, A; Luehring, F; Lund-Jensen, B; Lundberg, B; Ma, H; Mackeprang, R; Maio, A; Maleev, V P; Malek, F; Mandelli, L; Maneira, J; Mangin-Brinet, M; Manousakis, A; Mapelli, L; Marques, C; Marti i Garcia, S; Martin, F; Mathes, M; Mazzanti, M; McFarlane, K W; McPherson, R; Mchedlidze, G; Mehlhase, S; Meirosu, C; Meng, Z; Meroni, C; Mialkovski, V; Mikulec, B; Milstead, D; Minashvili, I; Mindur, B; Mitsou, V A; Moed, S; Monnier, E; Moorhead, G; Morettini, P; Morozov, S V; Mosidze, M; Mouraviev, S V; Moyse, E.W J; Munar, A; Myagkov, A; Nadtochi, A V; Nakamura, K; Nechaeva, P; Negri, A; Nemecek, S; Nessi, M; Nesterov, S Y; Newcomer, F M; Nikitine, I; Nikolaev, K; Nikolic-Audit, I; Ogren, H; Oh, S H; Oleshko, S B; Olszowska, J; Onofre, A; Padilla Aranda, C; Paganis, S; Pallin, D; Pantea, D; Paolone, V; Parodi, F; Parsons, J; Parzhitski, S; Pasqualucci, E; Passmore, S M; Pater, J; Patrichev, S; Peez, M; Perez Reale, V; Perini, L; Peshekhonov, V D; Petersen, J; Petersen, T C; Petti, R; Phillips, P W; Pilcher, J; Pina, J; Pinto, B; Podlyski, F; Poggioli, L; Poppleton, A; Poveda, J; Pralavorio, P; Pribyl, L; Price, M J; Prieur, D; Puigdengoles, C; Puzo, P; Ragusa, F; Rajagopalan, S; Reeves, K; Reisinger, I; Rembser, C; Bruckman de Renstrom, P.A.; Reznicek, P; Ridel, M; Risso, P; Riu, I; Robinson, D; Roda, C; Roe, S; Rohne, O.; Romaniouk, A; Rousseau, D; Rozanov, A; Ruiz, A; Rusakovich, N; Rust, D; Ryabov, Y F; Ryjov, V; Salto, O; Salvachua, B; Salzburger, A; Sandaker, H; Santamarina Rios, C.Santamarina; Santi, L; Santoni, C; Saraiva, J G; Sarri, F; Sauvage, G; Says, L P; Schaefer, M; Schegelsky, V A; Schiavi, C; Schieck, J; Schlager, G; Schlereth, J; Schmitt, C; Schultes, J; Schwemling, P; Schwindling, J; Seixas, J M; Seliverstov, D M; Serin, L; Sfyrla, A; Shalanda, N; Shaw, C; Shin, T; Shmeleva, A; Silva, J; Simion, S; Simonyan, M; Sloper, J E; Smirnov, S.Yu; Smirnova, L; Solans, C; Solodkov, A; Solovianov, O; Soloviev, I; Sosnovtsev, V V; Spano, F; Speckmayer, P; Stancu, S; Stanek, R; Starchenko, E; Straessner, A; Suchkov, S I; Suk, M; Szczygiel, R; Tarrade, F; Tartarelli, F; Tas, P; Tayalati, Y; Tegenfeldt, F; Teuscher, R; Thioye, M; Tikhomirov, V O; Timmermans, C.J.W P; Tisserant, S; Toczek, B; Tremblet, L; Troncon, C; Tsiareshka, P; Tyndel, M; Karagoz Unel, M.; Unal, G; Unel, G; Usai, G; Van Berg, R; Valero, A; Valkar, S; Valls, J A; Vandelli, W; Vannucci, F; Vartapetian, A; Vassilakopoulos, V I; Vasilyeva, L; Vazeille, F; Vernocchi, F; Vetter-Cole, Y; Vichou, I; Vinogradov, V; Virzi, J; Vivarelli, I; de Vivie, J B; Volpi, M; Vu Anh, T; Wang, C; Warren, M; Weber, J; Weber, M; Weidberg, A R; Weingarten, J; Wells, P S; Werner, P; Wheeler, S; Wiesmann, M; Wilkens, H; Williams, H H; Wingerter-Seez, I; Yasu, Y; Zaitsev, A; Zenin, A; Zenis, T; Zenonos, Z; Zhang, H; Zhelezko, A; Zhou, N

    2011-01-01

    The reconstruction of photons in the ATLAS detector is studied with data taken during the 2004 Combined Test Beam, where a full slice of the ATLAS detector was exposed to beams of particles of known energy at the CERN SPS. The results presented show significant differences in the longitudinal development of the electromagnetic shower between converted and unconverted photons as well as in the total measured energy. The potential to use the reconstructed converted photons as a means to precisely map the material of the tracker in front of the electromagnetic calorimeter is also considered. All results obtained are compared with a detailed Monte-Carlo simulation of the test-beam setup which is based on the same simulation and reconstruction tools as those used for the ATLAS detector itself.

  13. Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    FRAGNAUD, J; The ATLAS collaboration

    2014-01-01

    The trigger readout electronics of the ATLAS LAr Calorimeters will be improved for the Phase-I luminosity upgrade of the LHC to enhance the trigger feature extraction. Signals with higher spatial granularity will be digitized and processed by newly developed front-end and back-end components. In order to evaluate technical and performance aspects, a demonstrator system is being set up which is planned to be installed on the ATLAS detector during the upcoming LHC run. Results from system tests of the analog signal treatment, the trigger digitizer, the optical signal transmission and the FPGA-based back-end are reported.

  14. Status and perspecitves of liquid argon calorimeters

    International Nuclear Information System (INIS)

    The status of liquid argon calorimeters is reviewed, and experience obtained with these devices is described. Future perspectives of the liquid ionization chamber technique in calorimetry are also discussed. (orig.)

  15. Liquid argon neutrals detector (LAND) for PEP

    International Nuclear Information System (INIS)

    The physical effects limiting the gamma energy resolution of a liquid argon calorimeter without passive converter plates is discussed. An example of such a detector based on the General User's Magnet designed at this Summer Study is given

  16. Measurements on scintillation light from liquid argon

    International Nuclear Information System (INIS)

    It is shown that an argon calorimeter can operate as a scintillation detector, provided that xenon is added. With the addition of 170 ppm xenon a light yield of 70% has been obtained. In addition the light yield is determined under influence of an electric field, from differently ionising particles and by the use of aluminium mirrors acting as light guides. Finally first measurements with a photomultiplier working at liquid argon temperatures are reported. (orig.)

  17. A radiation-hard dual channel 4-bit pipeline for a 12-bit 40 MS/s ADC prototype with extended dynamic range for the ATLAS Liquid Argon Calorimeter readout electronics upgrade at the CERN LHC

    International Nuclear Information System (INIS)

    The design of a radiation-hard dual-channel 12-bit 40 MS/s pipeline ADC with extended dynamic range is presented, for use in the readout electronics upgrade for the ATLAS Liquid Argon Calorimeters at the CERN Large Hadron Collider. The design consists of two pipeline A/D channels with four Multiplying Digital-to-Analog Converters with nominal 12-bit resolution each. The design, fabricated in the IBM 130 nm CMOS process, shows a performance of 68 dB SNDR at 18 MHz for a single channel at 40 MS/s while consuming 55 mW/channel from a 2.5 V supply, and exhibits no performance degradation after irradiation. Various gain selection algorithms to achieve the extended dynamic range are implemented and tested

  18. ELECTROMAGNETIC COMPATIBILITY OF A DC POWER DISTRIBUTION SYSTEM FOR THE ATLAS LIQUID ARGON CALORIMETER COMPATIBILIDAD ELECTROMAGNÉTICA EN EL SISTEMA DE DISTRIBUCIÓN DE CORRIENTE CONTINUA PARA EL CALORÍMETRO DE ARGÓN LÍQUIDO EN ATLAS

    OpenAIRE

    George Blanchot; Luis Hervas; Jim Kierstead; Francesco Lanni; Sergio Rescia(Brookhaven National Lab); Mauricio Verdugo; Jorge Pontt; Ricardo Olivares; Hernán Robles; Sergio Díaz

    2008-01-01

    The front-end electronics of the ATLAS Liquid Argon Calorimeter is powered by DC/DC converters nearby the front-end crates. They are fed by AC/DC converters located in a remote control room through long power cables. The stability of the power distribution scheme is compromised by the impedance of the long interconnection cable, and proper matching of the converters dynamic impedances is required. Also, the long power cable fed by a powerful AC/DC converter is a source of electromagnetic inte...

  19. Near-infrared scintillation of liquid argon

    Science.gov (United States)

    Alexander, T.; Escobar, C. O.; Lippincott, W. H.; Rubinov, P.

    2016-03-01

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 μm motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  20. Pollution of liquid argon after neutron irradiation measured at SARA: summary of raw data

    CERN Document Server

    Andrieux, M L; de Saintignon, P; Ferrari, A; Hostachy, J Y; Martin, P; Wielers, M; Belymam, A; Hoummada, A; Merkel, B; Puzo, P M; Sauvage, D

    1998-01-01

    The SARA fast neutron facility has been used to irradiate various pieces of materials due to be used in the ATLAS electromagnetic calorimeter, immersed in a liquid argon cryostat. The subsequent pollution was measured. The raw data have been summarized in this paper.

  1. Current and future liquid argon neutrino experiments

    International Nuclear Information System (INIS)

    The liquid argon time projection chamber (LArTPC) detector technology provides an opportunity for precision neutrino oscillation measurements, neutrino cross section measurements, and searches for rare processes, such as SuperNova neutrino detection. These proceedings review current and future LArTPC neutrino experiments. Particular focus is paid to the ICARUS, MicroBooNE, LAr1, 2-LArTPC at CERN-SPS, LBNE, and 100 kton at Okinoshima experiments

  2. Attenuation of vacuum ultraviolet light in liquid argon

    CERN Document Server

    Neumeier, A; Oberauer, L; Potzel, W; Schönert, S; Dandl, T; Heindl, T; Ulrich, A; Wieser, J

    2015-01-01

    The transmission of liquid argon has been measured, wavelength resolved, for a wavelength interval from 118 to 250 nm. The wavelength dependent attenuation length is presented for pure argon. It is shown that no universal wavelength independent attenuation length can be assigned to liquid argon for its own fluorescence light due to the interplay between the wavelength dependent emission and absorption. A decreasing transmission is observed below 130 nm in both chemically cleaned and distilled liquid argon and assigned to absorption by the analogue of the first argon excimer continuum. For not perfectly cleaned argon a strong influence of impurities on the transmission is observed. Two strong absorption bands at 126.5 and 141.0 nm with approximately 2 and 4 nm width, respectively, are assigned to traces of xenon in argon. A broad absorption region below 180 nm is found for unpurified argon and tentatively attributed to the presence of water in the argon sample.

  3. Electron scattering and transport in liquid argon

    International Nuclear Information System (INIS)

    The transport of excess electrons in liquid argon driven out of equilibrium by an applied electric field is revisited using a multi-term solution of Boltzmann’s equation together with ab initio liquid phase cross-sections calculated using the Dirac-Fock scattering equations. The calculation of liquid phase cross-sections extends previous treatments to consider multipole polarisabilities and a non-local treatment of exchange, while the accuracy of the electron-argon potential is validated through comparison of the calculated gas phase cross-sections with experiment. The results presented highlight the inadequacy of local treatments of exchange that are commonly used in liquid and cluster phase cross-section calculations. The multi-term Boltzmann equation framework accounting for coherent scattering enables the inclusion of the full anisotropy in the differential cross-section arising from the interaction and the structure factor, without an a priori assumption of quasi-isotropy in the velocity distribution function. The model, which contains no free parameters and accounts for both coherent scattering and liquid phase screening effects, was found to reproduce well the experimental drift velocities and characteristic energies

  4. Liquid argon imaging a novel detection technology

    CERN Document Server

    Rubbia, Carlo

    2002-01-01

    Ionisation electrons may drift over large distances (meters) in a volume of highly purified liquid argon (O2 equivalent less than 0.1 ppb!) under the action of an electric field. With an appropriate readout system (i.e. a set of fine pitch wire grids) we have realised a massive, continuously sensitive 'bubble chamber' with multiple readouts of the same, small charge (a minimum ionising track segment, 2 mm long, yields • 10000 electrons). We have developed this technology since 1987, initially with small laboratory devices and later with progressively larger and more sophisticated detectors, the latest being the T600 module (740 ton of liquid Argon), which has been operated in Pavia, as a step toward the ICARUS programme in the Gran Sasso Laboratory (LNGS). With cloning of T600 we aim at a 3000 ton detector by 2005. Argon is a medium with density 1.4 g/cm3, similar in characteristics to the heavy freon used in the famous Gargamelle. With wire pitches of 2-3 mm, it provides an extremely high spatial re...

  5. Performance of the Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid Argon Calorimeters

    International Nuclear Information System (INIS)

    For the Phase-I luminosity upgrade of the LHC a higher granularity trigger readout of the ATLAS LAr Calorimeters is foreseen to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, which are grouped into 34000 so-called Super Cells, with 12 bit precision at 40 MHz and transfers the data on optical links to the digital processing system, which extracts the Super Cell energies. A demonstrator version of the complete system has now been installed and operated on the ATLAS detector. Results from the commissioning and performance measurements are reported

  6. Performance of the Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid-Argon Calorimeters

    CERN Document Server

    Dumont Dayot, Nicolas; The ATLAS collaboration

    2015-01-01

    For the Phase-I luminosity upgrade of the LHC a higher granularity trigger readout of the ATLAS LAr Calorimeters is foreseen in order to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, which are grouped into 34000 so-called Super Cells, with 12 bit precision at 40 MHz and transfers the data on optical links to the digital processing system, which extracts the Super Cell energies. A demonstrator version of the complete system has now been installed and operated on the ATLAS detector. Results from the commissioning and performance measurements will be reported.

  7. Performance of the Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Dumont Dayot, Nicolas; The ATLAS collaboration

    2015-01-01

    For the Phase-I luminosity upgrade of the LHC a higher granularity trigger readout of the ATLAS LAr Calorimeters is foreseen in order to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, which are grouped into 34000 so-called Super Cells, with 12 bit precision at 40 MHz and transfers the data on optical links to the digital processing system, which extracts the Super Cell energies. A demonstrator version of the complete system has now been installed and operated on the ATLAS detector. Results from the commissioning and performance measurements will be reported.

  8. Effects of Nitrogen contamination in liquid Argon

    Science.gov (United States)

    Acciarri, R.; Antonello, M.; Baibussinov, B.; Baldo-Ceolin, M.; Benetti, P.; Calaprice, F.; Calligarich, E.; Cambiaghi, M.; Canci, N.; Carbonara, F.; Cavanna, F.; Centro, S.; Cocco, A. G.; Di Pompeo, F.; Fiorillo, G.; Galbiati, C.; Gallo, V.; Grandi, L.; Meng, G.; Modena, I.; Montanari, C.; Palamara, O.; Pandola, L.; Piano Mortari, G. B.; Pietropaolo, F.; Raselli, G. L.; Roncadelli, M.; Rossella, M.; Rubbia, C.; Segreto, E.; Szelc, A. M.; Ventura, S.; Vignoli, C.

    2010-06-01

    A dedicated test of the effects of Nitrogen contamination in liquid Argon has been performed at the INFN-Gran Sasso Laboratory (LNGS, Italy) within the WArP R&D program. A detector has been designed and assembled for this specific task and connected to a system for the injection of controlled amounts of gaseous Nitrogen into the liquid Argon. The purpose of the test is to detect the reduction of the Ar scintillation light emission as a function of the amount of the Nitrogen contaminant injected in the Argon volume. A wide concentration range, spanning from ~ 10-1 ppm up to ~ 103 ppm, has been explored. Measurements have been done with electrons in the energy range of minimum ionizing particles (γ-conversion from radioactive sources). Source spectra at different Nitrogen contaminations are analyzed, showing sensitive reduction of the scintillation yield at increasing concentrations. Direct PMT signal acquisition exploiting high time resolution by fast waveform recording allowed high precision extraction of the main characteristics of the scintillation light emission in contaminated LAr. In particular, the decreasing behavior in lifetime and relative amplitude of the slow component is found to be appreciable starting from Script O(1 ppm) of Nitrogen concentrations. The rate constant of the quenching process induced by Nitrogen in liquid Ar has been found to be kQ(N2) = 0.11 ± 0.01 μs-1ppm-1, consistent with a previous measurement of this quantity but with significant improvement in precision. On the other hand, no evidence for absorption by N2 impurities has been found up to the higher concentrations here explored.

  9. Ion-beam excitation of liquid argon

    CERN Document Server

    Hofmann, M; Heindl, T; Neumeier, A; Oberauer, L; Potzel, W; Roth, S; Schönert, S; Wieser, J; Ulrich, A

    2015-01-01

    The scintillation light of liquid argon has been recorded wavelength and time resolved with very good statistics in a wavelength interval ranging from 118 nm through 970 nm. Three different ion beams, protons, sulfur ions and gold ions, were used to excite liquid argon. Only minor differences were observed in the wavelength-spectra obtained with the different incident particles. Light emission in the wavelength range of the third excimer continuum was found to be strongly suppressed in the liquid phase. In time-resolved measurements, the time structure of the scintillation light can be directly attributed to wavelength in our studies, as no wavelength shifter has been used. These measurements confirm that the singlet-to-triplet intensity ratio in the second excimer continuum range is a useful parameter for particle discrimination, which can also be employed in wavelength-integrated measurements as long as the sensitivity of the detector system does not rise steeply for wavelengths longer than 190 nm. Using ou...

  10. Near-infrared scintillation of liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, T. [Fermilab; Escobar, C. O. [Campinas State U.; Lippincott, W. H. [Fermilab; Rubinov, P. [Fermilab

    2016-03-03

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 $\\mu$m < $\\lambda$; < 1.5$\\mu$m). More controversial has been the question of the NIR light yield for condensed noble gases. We first present the motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  11. Near-infrared scintillation of liquid argon

    CERN Document Server

    Alexander, T; Lippincott, W H; Rubinov, P

    2016-01-01

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 $\\mu$m < $\\lambda$; < 1.5$\\mu$m). More controversial has been the question of the NIR light yield for condensed noble gases. We first present the motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  12. Direct WIMP Detection Using Scintillation Time Discrimination in Liquid Argon

    OpenAIRE

    Boulay, M. G.; Hime, A.

    2004-01-01

    Discrimination between electron and nuclear recoil events in a liquid argon scintillation detector has been demonstrated with simulations by using the differences in the scintillation photon time distribution between these classes of events. A discrimination power greater than 10^{8} is predicted for a liquid argon experiment with a 10 keV threshold, which would mitigate electron and gamma-ray backgrounds, including beta decays of 39-Ar and 42-Ar in atmospheric argon. A dark matter search usi...

  13. Liquid Argon Calorimeters Operation and Data Quality During the 2015 Proton Run

    CERN Document Server

    Camincher, Clement; The ATLAS collaboration

    2016-01-01

    In 2015 ATLAS operated with an excellent efficiency, recording an integrated luminosity of 3.9fb^{-1} at \\sqrt{s} = 13 TeV. The Liquid Argon (LAr) Calorimeter contributed to this effort by operating with a good data quality efficiency of 99.4% . This poster highlights the overall status, performances and data quality of the LAr Calorimeters during the first year of Run-2 operations.

  14. Neutron Inelastic Scattering Study of Liquid Argon

    International Nuclear Information System (INIS)

    The inelastic scattering functions for liquid argon have been measured at 85.2 K. The coherent scattering function was obtained from a measurement on pure A-36 and the incoherent function was derived from the result obtained from the A-36 sample and the result obtained from a mixture of A-36 and A-40 for which the scattering is predominantly incoherent. The data, which are presented as smooth scattering functions at constant values of the wave vector transfer in the range 10 - 44/nm, are corrected for multiple scattering contributions and for resolution effects. Such corrections are shown to be essential in the derivation of reliable scattering functions from neutron scattering data. The incoherent data are compared to recent molecular dynamics results and the mean square displacement as a function of time is derived. The coherent data are compared to molecular dynamics results and also, briefly, to some recent theoretical models

  15. Ideas for future liquid Argon detectors

    International Nuclear Information System (INIS)

    We outline a strategy for future experiments on neutrino and astroparticle physics based on the use, at different detector mass scales (100 ton and 100 kton), of the liquid Argon Time Projection Chamber (LAr TPC) technique. The LAr TPC technology has great potentials for both cases with large degree of interplay between the two applications and a strong synergy. The ICARUS R and D programme has demonstrated that the technology is mature and that one can built a large (∼ 1 kton) LAr TPC. We believe that one can conceive and design a very large mass LAr TPC with a mass of 100 kton by employing a monolithic technology based on the use of industrial, large volume cryogenic tankers developed by the petro-chemical industry. We show a potential implementation of a large LAr TPC detector. Such a detector would be an ideal match for a Superbeam[New J. Phys. 4 (2002) 88 [arXiv:hep-ph/0208047

  16. Z $\\rightarrow$ $\\tau\\tau$ Cross Section Measurement and Liquid-Argon Calorimeter Performance at High Rates at the ATLAS Experiment

    CERN Document Server

    Seifert, Frank

    In this study, a measurement of the production cross section of Standard Model $Z$ bosons in proton-proton collisions in the decay channel $Z\\rightarrow\\tau\\tau$ is performed with data of 1.34$\\,\\mathrm{fb^{-1}}$ - 1.55$\\,\\mathrm{fb^{-1}}$ recorded by the ATLAS experiment at the LHC at a center-of-mass energy of $\\sqrt{s}=7\\,\\mathrm{TeV}$. An event selection of the data is applied in order to obtain a sample enriched with $Z\\rightarrow\\tau\\tau$ events. After background estimations using data and Monte Carlo (MC) simulations, the fiducial cross sections in the sub-channels $Z\\rightarrow\\tau\\tau\\rightarrow e\\tau_h + 3\

  17. Pulse shape discrimination studies in a liquid Argon scintillation detector

    OpenAIRE

    Pollmann, T.

    2007-01-01

    Liquid rare gases have been gaining popularity as detector media in rare event searches, especially dark matter experiments, and one factor driving their adoption is the possibility to recognise different types of ionizing radiation by the pulse shapes they evoke. This work on pulse shape discrimination in a liquid argon scintillation detector was done in the framework of the GERDA experiment, where liquid argon scintillation signals may be used for background suppression purposes. Liquid arg...

  18. Liquid-argon cylindrical pulsed ionization chamber

    International Nuclear Information System (INIS)

    A liquid-argon cylindrical ionization chamber with a working volume of 200 cm2 is described. The chamber anode is made of stainless steel in the form of a hollow cylinder 30 mm in diameter and 140 mm in length. A beryllium bronze wire in diameter of 0.1 mm and at a spacing of 1 mm is used for winding the chamber screen grid. The chamber cathode is a brass thin-walled cylinder having an internal diameter of 56 mm and a height of 156 mm. The cathode-grid gap is 10 mm, the cathode-case gap is 2 mm. A 0.5 l cooling bath filled with liquid nitrogen is used to refrigirate the chamber. The chamber is evacuated to about 10-5 mm Hg. The total concentration of electronegative impurities in argon does not exceed 6x10-9. Dependences of the chamber counting and amplitude responses, on the cathode voltage under irradiation with γ-quanta at energies of 0.898 MeV and 1.836 MeV are given. The value of the energy resolution was evaluated by differentiating the high-energy edge of the Compton spectrum. The total width at a peak half-height constitutes 5% for an electron energy of 1.612 MeV. To achieve better resolution of the chamber it is necessary to reduce preamplifier noises by three times, to increase the working gap of the chamber and decrease the grid-anode gap

  19. ELECTROMAGNETIC COMPATIBILITY OF A DC POWER DISTRIBUTION SYSTEM FOR THE ATLAS LIQUID ARGON CALORIMETER COMPATIBILIDAD ELECTROMAGNÉTICA EN EL SISTEMA DE DISTRIBUCIÓN DE CORRIENTE CONTINUA PARA EL CALORÍMETRO DE ARGÓN LÍQUIDO EN ATLAS

    Directory of Open Access Journals (Sweden)

    George Blanchot

    2008-06-01

    Full Text Available The front-end electronics of the ATLAS Liquid Argon Calorimeter is powered by DC/DC converters nearby the front-end crates. They are fed by AC/DC converters located in a remote control room through long power cables. The stability of the power distribution scheme is compromised by the impedance of the long interconnection cable, and proper matching of the converters dynamic impedances is required. Also, the long power cable fed by a powerful AC/DC converter is a source of electromagnetic interferences in the experimental area. The optimal grounding and shielding configuration to minimize these EMI is discussed.El Calorímetro de Argón Líquido en ATLAS es alimentado por convertidores DC/DC localizados cerca de sus compartimientos. Ellos son alimentados por convertidores AC/DC localizados en una sala de control lejana conectados mediante cables largos de poder. La estabilidad del sistema de distribución es sensible a la impedancia del cable largo de interconexión y son requeridos los convertidores apropiados para estabilizar la dinámica de la impedancia. También, el cable largo alimentado por el convertidor AC/DC es una fuente de interferencia electromagnética en el área experimental. En este trabajo se analiza La óptima configuración de aterrizamiento y blindaje para minimizar los efectos de EMI.

  20. Scintillation efficiency of liquid argon in low energy neutron-argon scattering

    International Nuclear Information System (INIS)

    Experiments searching for weak interacting massive particles with noble gases such as liquid argon require very low detection thresholds for nuclear recoils. A determination of the scintillation efficiency is crucial to quantify the response of the detector at low energy. We report the results obtained with a small liquid argon cell using a monoenergetic neutron beam produced by a deuterium-deuterium fusion source. The light yield relative to electrons was measured for six argon recoil energies between 11 and 120 keV at zero electric drift field

  1. Evidence of electric breakdown induced by bubbles in liquid argon

    CERN Document Server

    Bay, F; Murphy, S; Resnati, F; Rubbia, A; Sergiampietri, F; Wu, S

    2014-01-01

    We report on the results of a high voltage test in liquid argon in order to measure its dielectric rigidity. Under stable conditions and below the boiling point, liquid argon was found to sustain a uniform electric field of 100 kV/cm, applied in a region of 20 cm$^2$ area across 1 cm thick gap. When the liquid is boiling, breakdowns may occur at electric fields as low as 40 kV/cm. This test is one of the R&D efforts towards the Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER) as proposed Liquid Argon Time Projection Chamber (LAr TPC) for the LBNO observatory for neutrino physics, astrophysics and nucleon decay searches.

  2. A purity monitoring system for liquid argon calorimeters

    International Nuclear Information System (INIS)

    For liquid argon calorimeters electronegative impurities dissolved in the medium degrade the detector response and deteriorate the energy resolution, especially at high energies. A concept for a purity monitoring system for liquid argon calorimeters has been developed and is presented here. Special combined monitors of 241Am- and 207Bi-cells are used to monitor the concentration of impurities. The working principle as well as results from test measurements are discussed

  3. Studies of Electron Avalanche Behavior in Liquid Argon

    OpenAIRE

    Kim, J.G.; Dardin, S. M.; Jackson, K.H.; Kadel, R. W.(Lawrence Berkeley National Laboratory and University of California, 94720, Berkeley, California, USA); Kadyk, J. A.; Peskov, V.; Wenzel, W. A.

    2002-01-01

    Electron avalanching in liquid argon is being studied as a function of voltage, pressure, radiation intensity, and the concentrations of certain additives, especially xenon. The avalanches produced in an intense electric field at the tip of a tungsten needle are initiated by ionization from a moveable americium (241Am) gamma ray source. Photons from xenon excimers are detected as photomultiplier signals in coincidence with the current pulse from the needle. In pure liquid argon the avalanche ...

  4. LArGe - A liquid argon scintillation veto for GERDA

    OpenAIRE

    Heisel, M.(Max-Planck-Institut für Kernphysik, Heidelberg, Germany)

    2011-01-01

    LArGe is a Gerda low-background test facility to study novel background suppression methods in a low-background environment, for possible applications in the Gerda experiment. Gerda searches for the neutrinoless double-beta decay in 76Ge, by operating naked germanium detectors submersed into 65 m3 of liquid argon. Similarly, LArGe runs Ge-detectors in 1 m3 (1.4 tons) of liquid argon, which in addition is instrumented with photomultipliers to detect argon scintillation light. The light is used...

  5. Characterisation of GERDA Phase-I detectors in liquid argon

    International Nuclear Information System (INIS)

    GERDA will search for neutrinoless double beta decay in 76Ge by submerging bare enriched HPGe detectors in liquid argon. In GERDA Phase-I, reprocessed enriched-Ge detectors, which were previously operated by the Heidelberg-Moscow and IGEX collaborations, and reprocessed natural-Ge detectors from Genius-TF, will be redeployed. We have tested the operation and performance of bare HPGe detectors in liquid nitrogen and in liquid argon over more than three years with three non-enriched p-type prototype detectors. The detector handling and mounting procedures have been defined and the Phase-I detector technology, the low-mass assembly and the long-term stability in liquid argon have been tested successfully. The Phase-I detectors were reprocessed by Canberra Semiconductor NV, Olen, according to their standard technology but without the evaporation of a passivation layer. After their reprocessing, the detectors have been mounted in their low-mass holders and their characterisation in liquid argon performed. The leakage current, the counting characteristics and the efficiency of the detectors have been measured. The testing of the detectors was carried out in the liquid argon test stand of the GERDA underground Detector Laboratory (GDL) at LNGS. The detectors are now stored underground under vacuum until their operation in GERDA.

  6. The Effects of Dissolved Methane upon Liquid Argon Scintillation Light

    CERN Document Server

    Jones, B J P; Back, H O; Collin, G; Conrad, J M; Greene, A; Katori, T; Pordes, S; Toups, M

    2013-01-01

    In this paper we report on measurements of the effects of dissolved methane upon argon scintillation light. We monitor the light yield from an alpha source held 20 cm from a cryogenic photomultiplier tube (PMT) assembly as methane is injected into a high-purity liquid argon volume. We observe significant suppression of the scintillation light yield by dissolved methane at the 10 part per billion (ppb) level. By examining the late scintillation light time constant, we determine that this loss is caused by an absorption process and also see some evidence of methane-induced scintillation quenching at higher concentrations (50-100 ppb). Using a second PMT assembly we look for visible re-emission features from the dissolved methane which have been reported in gas-phase argon methane mixtures, and we find no evidence of visible re-emission from liquid-phase argon methane mixtures at concentrations between 10 ppb and 0.1%.

  7. Attenuation measurements of vacuum ultraviolet light in liquid argon revisited

    CERN Document Server

    Neumeier, A; Himpsl, A; Hofmann, M; Oberauer, L; Potzel, W; Schönert, S; Ulrich, A

    2015-01-01

    The attenuation of vacuum ultraviolet light in liquid argon in the context of its application in large liquid noble gas detectors has been studied. Compared to a previous publication several technical issues concerning transmission measurements in general are addressed and several systematic effects were quantitatively measured. Wavelength-resolved transmission measurements have been performed from the vacuum ultraviolet to the near-infrared region. On the current level of sensitivity with a length of the optical path of 11.6 cm, no xenon-related absorption effects could be observed, and pure liquid argon is fully transparent down to the short wavelength cut-off of the experimental setup at 118 nm. A lower limit for the attenuation length of pure liquid argon for its own scintillation light has been estimated to be 1.10 m based on a very conservative approach.

  8. Photoionization in liquid argon doped with trimethylamine or triethylamine

    International Nuclear Information System (INIS)

    Ionization yields for alpha particles and 1 MeV electrons in liquid argon doped with trimethylamine and with triethylamine have been measured. In both liquids, a collected charge larger than Anderson's results is observed for alpha particles although that for electrons is similar to Anderson's value. By using a new equation for the collected charge, the photoionization quantum efficiencies for scintillation light in liquid argon are estimated to be 0.35+-0.05 for trimethylamine and greater than 0.23+-0.03 for triethylamine. (orig.)

  9. Energy resolution for α-particles in doped liquid argon

    International Nuclear Information System (INIS)

    The report describes experiments on the effect of allene doped in liquid argon. In the case of doped argon, a large amount of charge is obtained even at low electric fields and the measured charge increases with the field gradually. This can be explained as follows; part of deposited energy which does not form charge in pure argon contributes to charge signal in doped argon through scintillation photons which ionize allene molecules. The main factors determining the energy resolution for α-particles are considered to be (1) fluctuation in the number of produced ion-electron pairs as expressed by the Fano factor, (2) fluctuation in recombination process, (3) fluctuation in photoionization, (4) fluctuation due to the condition of radioactive source and surface of electrodes, (5) fluctuation in geometrical efficiency due to the range and emission angle of α-particles in liquid argon, and (6) electronic noise of amplifier. The factors (1) and (3) can be neglected because of a large number of associated electrons or photons. In pure liquid argon, the factor (2) may be a cause of bad resolution since the fraction of the produced ion-electron paris which do not recombine is small and the photoionization process never occurs for photons emitted through recombination. (N.K.)

  10. On the electric breakdown in liquid argon at centimeter scale

    Science.gov (United States)

    Auger, M.; Blatter, A.; Ereditato, A.; Goeldi, D.; Janos, S.; Kreslo, I.; Luethi, M.; von Rohr, C. Rudolf; Strauss, T.; Weber, M. S.

    2016-03-01

    We present a study on the dependence of electric breakdown discharge properties on electrode geometry and the breakdown field in liquid argon near its boiling point. The measurements were performed with a spherical cathode and a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of the time evolution of the breakdown volt-ampere characteristics was performed for the first time. It revealed a slow streamer development phase in the discharge. The results of a spectroscopic study of the visible light emission of the breakdowns complement the measurements. The light emission from the initial phase of the discharge is attributed to electro-luminescence of liquid argon following a current of drifting electrons. These results contribute to set benchmarks for breakdown-safe design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).

  11. On the Electric Breakdown in Liquid Argon at Centimeter Scale

    CERN Document Server

    Auger, M; Ereditato, A; Goeldi, D; Janos, S; Kreslo, I; Luethi, M; von Rohr, C Rudolf; Strauss, T; Weber, M S

    2015-01-01

    We present a study on the dependence of electric breakdown discharge parameters on electrode geometry and the breakdown field in liquid argon near its boiling point. The measurements were performed with a spherical cathode and a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of the time evolution of the breakdown volt-ampere characteristics was performed for the first time. It revealed a slow streamer development phase in the discharge. The results of a spectroscopic study of the visible light emission of the breakdowns complement the measurements. The light emission from the initial phase of the discharge is attributed to electro-luminescence of liquid argon following a current of drifting electrons. These results contribute to set benchmarks for breakdown-safe design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).

  12. Liquid Argon Calorimetry with LHC-Performance Specifications

    CERN Multimedia

    2002-01-01

    % RD-3 Liquid Argon Calorimetry with LHC-Performance Specifications \\\\ \\\\Good electromagnetic and hadronic calorimetry will play a central role in an LHC detector. Among the techniques used so far, or under development, the liquid argon sampling calorimetry offers high radiation resistence, good energy resolution (electromagnetic and hadronic), excellent calibration stability and response uniformity. Its rate capabilities, however, do not yet match the requirements for LHC. \\\\ \\\\The aim of this proposal is to improve the technique in such a way that high granularity, good hermiticity and adequate rate capabilities are obtained, without compromising the above mentioned properties. To reach this goal, we propose to use a novel structure, the $^{\\prime\\prime}$accordion$^{\\prime\\prime}$, coupled to fast preamplifiers working at liquid argon temperature. Converter and readout electrodes are no longer planar and perpendicular to particles, as usual, but instead they are wiggled around a plane containing particles. ...

  13. Argon Purification Studies and a Novel Liquid Argon Re-circulation System

    CERN Document Server

    Mavrokoridis, K; Coleman, J; Lightfoot, P K; McCauley, N; McCormick, K J; Touramanis, C

    2011-01-01

    Future giant liquid argon (LAr) time projection chambers (TPCs) require a purity of better than 0.1 parts per billion (ppb) to allow the ionised electrons to drift without significant capture by any electronegative impurities. We present a comprehensive study of the effects of electronegative impurity on gaseous and liquid argon scintillation light, an analysis of the efficacy of various purification chemicals, as well as the Liverpool LAr setup, which utilises a novel re-circulation purification system. Of the impurities tested - Air, O_2, H_2O, N_2 and CO_2 in the range of between 0.01 ppm to 1000 ppm - H_2O was found to have the most profound effect on gaseous argon scintillation light, and N_2 was found to have the least. Additionally, a correlation between the slow component decay time and the total energy deposited with 0.01 ppm - 100 ppm O_2 contamination levels in liquid argon has been established. The superiority of molecular sieves over anhydrous complexes at absorbing Ar gas, N_2 gas and H_2O vapou...

  14. Study of Liquid Argon Dopants for LHC Hadron Calorimetry

    CERN Multimedia

    2002-01-01

    Hadron calorimetry based on the Liquid Argon Ionisation Chamber technique is one of the choice techniques for LHC-experimentation. A systematic study of the effect of selected dopants on Liquid Argon (LAr) will be carried out with the aim to achieve an improvement on: \\item (i)~``Fast Liquid Argon'' search and study of dopants to increase the drift velocity. It has been already shown that CH&sub4. added at a fraction of one percent increases the drift velocity by a factor of two or more. \\item (ii)~``Compensated Liquid Argon'' search and study of dopants to increase the response to densely ionising particles, resulting in improved compensation, such as photosensitive dopants. \\end{enumerate}\\\\ \\\\ Monitoring of the parameters involved in understanding the response of a calorimeter is essential. In case of doped LAr, the charge yield, the non-saturated drift velocity and the electron lifetime in the liquid should be precisely and simultaneously monitored as they all vary with the level of dopant concentrati...

  15. Energy resolution studies of liquid argon ionization detectors

    International Nuclear Information System (INIS)

    A gridded ionization chamber was used to study the energy resolution in liquid argon with electrons from a 207Bi radioactive source. Argon was purified in the gas phase with a simple and reliable system, capable of reducing the impurity level below 1 ppb O2 equivalent, as inferred by a pulse shape analysis of the ionization signals. The electron spectrum was measured at different drift fields, up to 10.9 KV/cm. At this maximum field, a total energy resolution of 32 keV (fwhm), corresponding to a noise-subtracted energy resolution of 26 keV (fwhm), was obtained for the 976 keV conversion electron line. This value is the best reported so far in liquid argon but is still a factor of seven worse than the theoretical limit set by the Fano factor. The reasons for this discrepancy are discussed. (orig.)

  16. Uranium-liquid argon calorimetry: preliminary results from the DO tests

    International Nuclear Information System (INIS)

    The motivations for using uranium and liquid argon in sampling calorimetry are reviewed and the pros and cons of the technique are discussed. Preliminary results of the DO uranium-liquid argon test program are presented. 9 refs., 7 figs

  17. Resource Review Board Celebrates the Magnet and Liquid Argon Barrel Tests in Hall 180

    CERN Document Server

    Jenni, P.

    2004-01-01

    Address by the Director-General, R. Aymar, in front of the barrel cryostat. On 25th October 2004 many RRB delegates and guests, ATLAS National Contact Physicists, and colleagues from far and from CERN working on the Liquid Argon calorimeter and the magnet system were gathering in Hall 180 to celebrate the major milestones reached during the past months in this hall: the successful cold tests of the first barrel toroid coil, of the solenoid, and of the barrel Liquid Argon calorimeter. About 250 people spent a relaxing evening after the speeches by the Director-General R. Aymar and by the spokesperson who gave the following address: 'It is a great pleasure for me to welcome you all here in Hall 180 in the name of the ATLAS Collaboration! With a few words I would like to recall why we are actually here today to share, what I hope, is a relaxed and joyful moment. To concentrate it all in one sentence I could say: To thank cordially all the main actors for the enormous work accomplished here over many years,...

  18. Measurement of Longitudinal Electron Diffusion in Liquid Argon

    CERN Document Server

    Li, Yichen; Thorn, Craig; Qian, Xin; Diwan, Milind; Joshi, Jyoti; Kettell, Steve; Morse, William; Rao, Triveni; Stewart, Jim; Tang, Wei; Viren, Brett

    2015-01-01

    We report the measurement of longitudinal electron diffusion coefficients in liquid argon for electric fields between 100 and 2000 V/cm with a gold photocathode as a bright electron source. The measurement principle, apparatus, and data analysis are described. Our results, which are consistent with previous measurements in the region between 100 to 350 V/cm [1] , are systematically higher than the prediction of Atrazhev-Timoshkin[2], and represent the world's best measurement in the region between 350 to 2000 V/cm. The quantum efficiency of the gold photocathode, the drift velocity and longitudinal diffusion coefficients in gas argon are also presented.

  19. LArGe. A liquid argon scintillation veto for GERDA

    International Nuclear Information System (INIS)

    LArGe is a GERDA low-background test facility to study novel background suppression methods in a low-background environment, for possible applications in the GERDA experiment. GERDA searches for the neutrinoless double-beta decay in 76Ge, by operating naked germanium detectors submersed into 65 m3 of liquid argon. Similarly, LArGe runs Ge-detectors in 1 m3 (1.4 tons) of liquid argon, which in addition is instrumented with photomultipliers to detect argon scintillation light. The light is used in anti-coincidence with the germanium detectors, to effectively suppress background events that deposit energy in the liquid argon. This work adresses the design, construction, and commissioning of LArGe. The background suppression efficiency has been studied in combination with a pulse shape discrimination (PSD) technique for various sources, which represent characteristic backgrounds to GERDA. Suppression factors of a few times 103 have been achieved. First background data of LArGe (without PSD) yield a background index of (0.12-4.6).10-2 cts/(keV.kg.y) (90% c.l.), which is at the level of the Gerda phase I design goal. Furthermore, for the first time we measure the natural 42Ar abundance (in parallel to Gerda), and have indication for the 2νββ-decay in natural germanium. (orig.)

  20. LArGe. A liquid argon scintillation veto for GERDA

    Energy Technology Data Exchange (ETDEWEB)

    Heisel, Mark

    2011-04-13

    LArGe is a GERDA low-background test facility to study novel background suppression methods in a low-background environment, for possible applications in the GERDA experiment. GERDA searches for the neutrinoless double-beta decay in {sup 76}Ge, by operating naked germanium detectors submersed into 65 m{sup 3} of liquid argon. Similarly, LArGe runs Ge-detectors in 1 m{sup 3} (1.4 tons) of liquid argon, which in addition is instrumented with photomultipliers to detect argon scintillation light. The light is used in anti-coincidence with the germanium detectors, to effectively suppress background events that deposit energy in the liquid argon. This work adresses the design, construction, and commissioning of LArGe. The background suppression efficiency has been studied in combination with a pulse shape discrimination (PSD) technique for various sources, which represent characteristic backgrounds to GERDA. Suppression factors of a few times 10{sup 3} have been achieved. First background data of LArGe (without PSD) yield a background index of (0.12-4.6).10{sup -2} cts/(keV.kg.y) (90% c.l.), which is at the level of the Gerda phase I design goal. Furthermore, for the first time we measure the natural {sup 42}Ar abundance (in parallel to Gerda), and have indication for the 2{nu}{beta}{beta}-decay in natural germanium. (orig.)

  1. Performance du calorimètre à argon liquide et recherche du boson de Higgs dans son canal de désintégration $H\\to ZZ^{(*)} \\to 4\\ell$ avec l'expérience ATLAS auprès du LHC.

    CERN Document Server

    Tiouchichine, Elodie

    The work presented in this thesis within the ATLAS collaboration was performed in the context of the discovery of a new particle at the LHC in the search for the Standard Model Higgs boson. My contribution to the Higgs boson search is focused in the $H \\to ZZ^* \\to 4 \\ell$ channel at different level, from the data taking to the physics analysis. After a theoretical introduction, the LHC and the ATLAS detector are presented as well as their performance during the 2011 and 2012 runs. A particular consideration is given to the liquid argon calorimeters and to the data quality assessment of this system. The validation of the data recorded during non-nominal high voltage conditions is presented. This study allowed to recover 2\\% of the data collected available for physics analyses. This has a direct impact on the $H \\to ZZ^* \\to 4 \\ell$ channel were the number of signal events expected is very low. In order to optimize the acceptance of the four electrons decay channel, novel electron reconstruction algorithms wer...

  2. Demonstration and comparison of photomultiplier tubes at liquid Argon temperature

    International Nuclear Information System (INIS)

    Liquified noble gases are widely used as a target in direct Dark Matter searches. Signals from scintillation in the liquid, following energy deposition from the recoil nuclei scattered by Dark Matter particles (e.g. WIMPs), should be recorded down to very low energies by photosensors suitably designed to operate at cryogenic temperatures. Liquid Argon based detectors for Dark Matter searches currently implement photomultiplier tubes for signal read-out. In the last few years PMTs with photocathodes operating down to liquid Argon temperatures (87 K) have been specially developed with increasing Quantum Efficiency characteristics. The most recent of these, Hamamatsu Photonics K.K. Mod. R11065 with peak QE up to about 35%, has been extensively tested within the R and D program of the WArP Collaboration. During these tests the Hamamatsu PMTs showed excellent performance and allowed obtaining a light yield around 7 phel/keVee in a Liquid Argon detector with a photocathodic coverage in the 12% range, sufficient for detection of events down to few keVee of energy deposition. This shows that this new type of PMT is suited for experimental applications, in particular for new direct Dark Matter searches with LAr-based experiments.

  3. Demonstration and comparison of photomultiplier tubes at liquid Argon temperature

    Science.gov (United States)

    Acciarri, R.; Antonello, M.; Boffelli, F.; Cambiaghi, M.; Canci, N.; Cavanna, F.; Cocco, A. G.; Deniskina, N.; Di Pompeo, F.; Fiorillo, G.; Galbiati, C.; Grandi, L.; Kryczynski, P.; Meng, G.; Montanari, C.; Palamara, O.; Pandola, L.; Perfetto, F.; Piano Mortari, G. B.; Pietropaolo, F.; Raselli, G. L.; Rubbia, C.; Segreto, E.; Szelc, A. M.; Triossi, A.; Ventura, S.; Vignoli, C.; Zani, A.

    2012-01-01

    Liquified noble gases are widely used as a target in direct Dark Matter searches. Signals from scintillation in the liquid, following energy deposition from the recoil nuclei scattered by Dark Matter particles (e.g. WIMPs), should be recorded down to very low energies by photosensors suitably designed to operate at cryogenic temperatures. Liquid Argon based detectors for Dark Matter searches currently implement photomultiplier tubes for signal read-out. In the last few years PMTs with photocathodes operating down to liquid Argon temperatures (87 K) have been specially developed with increasing Quantum Efficiency characteristics. The most recent of these, Hamamatsu Photonics K.K. Mod. R11065 with peak QE up to about 35%, has been extensively tested within the R&D program of the WArP Collaboration. During these tests the Hamamatsu PMTs showed excellent performance and allowed obtaining a light yield around 7 phel/keVee in a Liquid Argon detector with a photocathodic coverage in the 12% range, sufficient for detection of events down to few keVee of energy deposition. This shows that this new type of PMT is suited for experimental applications, in particular for new direct Dark Matter searches with LAr-based experiments.

  4. Development of cryogenic installations for large liquid argon neutrino detectors

    CERN Document Server

    Adamowski, M; Geynisman, M; Hentschel, S; Montanari, D; Nessi, M; Norris, B

    2015-01-01

    A proposal for a very large liquid argon (68,000 kg) based neutrino detector is being studied. To validate the design principles and the detector technology, and to gain experience in the development of the cryostats and the cryogenic systems needed for such large experiments, several smaller scale installations will be developed and implemented, at Fermilab and CERN. The cryogenic systems for these installations will be developed, constructed, installed and commissioned by an international engineering team. These installations shall bring the required cooling power under specific conditions to the experiments for the initial cool-down and the long term operation, and shall also guarantee the correct distribution of the cooling power within the cryostats to ensure a homogeneous temperature distribution within the cryostat itself. The cryogenic systems shall also include gaseous and liquid phase argon purification devices to be used to reach and maintain the very stringent purity requirements needed for these...

  5. Scintillation time dependence and pulse shape discrimination in liquid argon

    International Nuclear Information System (INIS)

    Using a single-phase liquid argon detector with a signal yield of 4.85 photoelectrons per keV of electronic-equivalent recoil energy (keVee), we measure the scintillation time dependence of both electronic and nuclear recoils in liquid argon down to 5 keVee. We develop two methods of pulse shape discrimination to distinguish between electronic and nuclear recoils. Using one of these methods, we measure a background- and statistics-limited level of electronic recoil contamination to be 7.6x10-7 between 52 and 110 keV of nuclear recoil energy (keVr) for a nuclear recoil acceptance of 50% with no nuclear recoil-like events above 62 keVr. Finally, we develop a maximum likelihood method of pulse shape discrimination based on the measured scintillation time dependence

  6. Demonstration of a Lightguide Detector for Liquid Argon TPCs

    CERN Document Server

    Bugel, L; Ignarra, C; Jones, B J P; Katori, T; Smidt, T; Tanaka, H -K

    2011-01-01

    We report demonstration of light detection in liquid argon using an acrylic lightguide detector system. This opens the opportunity for development of an inexpensive, large-area light collection system for large liquid argon time projection chambers. The guides are constructed of acrylic, with TPB embedded in a surface coating with a matching index of refraction. We study the response to early scintillation light produced by a 5.3 MeV alpha. We measure coating responses from 7 to 8 PE on average, compared to an ideal expectation of 10 PE on average. We estimate the attenuation length of light along the lightguide bar to be greater than 0.5 m. The coating response and the attenuation length can be improved; we show, however, that these results are already sufficient for triggering in a large detector.

  7. Electron Neutrino Classification in Liquid Argon Time Projection Chamber Detector

    OpenAIRE

    Płoński, Piotr; Stefan, Dorota; Sulej, Robert; Zaremba, Krzysztof

    2015-01-01

    Neutrinos are one of the least known elementary particles. The detection of neutrinos is an extremely difficult task since they are affected only by weak sub-atomic force or gravity. Therefore large detectors are constructed to reveal neutrino's properties. Among them the Liquid Argon Time Projection Chamber (LAr-TPC) detectors provide excellent imaging and particle identification ability for studying neutrinos. The computerized methods for automatic reconstruction and identification of parti...

  8. Operational performance of a large liquid argon photon calorimeter

    International Nuclear Information System (INIS)

    We describe the performance of a large (0.9x1.4 m2) liquid argon photon calorimeter in high energy experiments at Fermilab. Resolutions for π0 and electron showers, obtained under data-taking conditions, are compared with electron-beam calibration results. Exceptional spatial and time resolutions have been achieved for isolated showers (sigmasub(x,y)0 data up to 180 GeV are presented. (orig.)

  9. Elastic properties of liquid and solid argon in nanopores.

    Science.gov (United States)

    Schappert, Klaus; Pelster, Rolf

    2013-10-16

    We have measured sorption isotherms and determined the intrinsic longitudinal elastic modulus β(Ar,ads) of nanoconfined material via ultrasonic measurements combined with a special effective medium analysis. In the liquid regime the adsorbate only contributes to the measured effective properties when the pores are completely filled and the modulus is bulklike. At partial fillings its contribution is cancelled out by the high compressibility of the vapour phase. In contrast, at lower temperatures frozen argon as well as underlying liquid surface layers cause a linear increase of the effective longitudinal modulus upon filling. During sorption the contribution of the liquid surface layers near the pore wall β(Ar,surf) increases with the thickness of the solid layers reaching the bulk value β(Ar,liquid) only in the limit of complete pore filling. We interpret this effect as due to the gradual stiffening of the solid argon membrane. The measurements and their analysis show that longitudinal ultrasonic waves are well suited to the study of the elastic properties and liquid-solid phase transitions in porous systems. This method should also help to detect the influence of nanoconfinement on elastic properties in further research. PMID:24057946

  10. A liquid argon scintillation veto for the Gerda experiment

    Energy Technology Data Exchange (ETDEWEB)

    Wegmann, Anne [Max-Planck Institut fuer Kernphysik, Heidelberg (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    Gerda is an experiment to search for the neutrinoless double beta decay of {sup 76}Ge. Bare germanium detectors are operated in a cryostat with 65 m{sup 3} of liquid argon (LAr). To reach the aspired background index of ≤10{sup -3} cts/(keV.kg.yr) for Phase II active background-suppression techniques will be applied, including an active liquid argon veto (LAr veto). A light instrumentation of LAr installed in the LArGe test facility has demonstrated that the detection of argon scintillation light can be used to effectively suppress background events in the germanium, which simultaneously deposit energy in LAr. Based on these results, Gerda pursues several options for the light instrumentation, which have to be compatible with the stringent radiopurity requirements of the experiment and should provide a significant suppression of the background in the region of interest around Q{sub ββ} at 2039 keV. This talk gives an account of the competing design options under investigation in the Gerda collaboration. The design options using photomultiplier tubes (PMT) and silicon photomultipliers (SiPM) are discussed, together with their expected performance from Monte Carlo simulations. In addition, the progress of development is reported, along with the design criteria for light instrumentation in Gerda.

  11. A liquid argon scintillation veto for the Gerda experiment

    International Nuclear Information System (INIS)

    Gerda is an experiment to search for the neutrinoless double beta decay of 76Ge. Bare germanium detectors are operated in a cryostat with 65 m3 of liquid argon (LAr). To reach the aspired background index of ≤10-3 cts/(keV.kg.yr) for Phase II active background-suppression techniques will be applied, including an active liquid argon veto (LAr veto). A light instrumentation of LAr installed in the LArGe test facility has demonstrated that the detection of argon scintillation light can be used to effectively suppress background events in the germanium, which simultaneously deposit energy in LAr. Based on these results, Gerda pursues several options for the light instrumentation, which have to be compatible with the stringent radiopurity requirements of the experiment and should provide a significant suppression of the background in the region of interest around Qββ at 2039 keV. This talk gives an account of the competing design options under investigation in the Gerda collaboration. The design options using photomultiplier tubes (PMT) and silicon photomultipliers (SiPM) are discussed, together with their expected performance from Monte Carlo simulations. In addition, the progress of development is reported, along with the design criteria for light instrumentation in Gerda.

  12. ARAPUCA a new device for liquid argon scintillation light detection

    International Nuclear Information System (INIS)

    We present a totally innovative device for the detection of liquid argon scintillation light, that has been named ARAPUCA (Argon R and D Advanced Program at UniCAmp). It is composed of a passive light collector and of active devices. The latters are standard SiPMs that operate at liquid argon temperature, while the passive collector is based on a new technology, never explored in this field before. It is a photon trap, that allows to collect light with extremely high efficiency. The total detection efficiency of the device can be tuned by modifying the ratio between the area of the active devices (SiPM) and the area of the optical window. For example, it will allow to reach a detection efficiency at the level of 1% on a surface of 50 × 50 cm2 with an active coverage of 2 × 2 cm2 (two/three large area SiPM). It is also a cheap device, since the major part of its cost is represented by the active devices. For these reason this appears to be the ideal device for scintillation light detection in large Time Projection Chambers. With appropriate modifications it can be used also in next generation Dark Matter detectors

  13. ARAPUCA a new device for liquid argon scintillation light detection

    Science.gov (United States)

    Machado, A. A.; Segreto, E.

    2016-02-01

    We present a totally innovative device for the detection of liquid argon scintillation light, that has been named ARAPUCA (Argon R&D Advanced Program at UniCAmp). It is composed of a passive light collector and of active devices. The latters are standard SiPMs that operate at liquid argon temperature, while the passive collector is based on a new technology, never explored in this field before. It is a photon trap, that allows to collect light with extremely high efficiency. The total detection efficiency of the device can be tuned by modifying the ratio between the area of the active devices (SiPM) and the area of the optical window. For example, it will allow to reach a detection efficiency at the level of 1% on a surface of 50 × 50 cm2 with an active coverage of 2 × 2 cm2 (two/three large area SiPM). It is also a cheap device, since the major part of its cost is represented by the active devices. For these reason this appears to be the ideal device for scintillation light detection in large Time Projection Chambers. With appropriate modifications it can be used also in next generation Dark Matter detectors.

  14. Measurement of longitudinal electron diffusion in liquid argon

    Science.gov (United States)

    Li, Yichen; Tsang, Thomas; Thorn, Craig; Qian, Xin; Diwan, Milind; Joshi, Jyoti; Kettell, Steve; Morse, William; Rao, Triveni; Stewart, James; Tang, Wei; Viren, Brett

    2016-04-01

    We report the measurement of longitudinal electron diffusion coefficients in liquid argon for electric fields between 100 and 2000 V/cm with a gold photocathode as a bright electron source. The measurement principle, apparatus, and data analysis are described. In the region between 100 and 350 V/cm, our results show a discrepancy with the previous measurement [1]. In the region between 350 and 2000 V/cm, our results represent the world's best measurement. Over the entire measured electric field range, our results are systematically higher than the calculation of Atrazhev-Timoshkin [2]. The quantum efficiency of the gold photocathode, the drift velocity and longitudinal diffusion coefficients in gas argon are also presented.

  15. Evaporation and condensation at a liquid surface. I. Argon

    Science.gov (United States)

    Yasuoka, Kenji; Matsumoto, Mitsuhiro; Kataoka, Yosuke

    1994-11-01

    Molecular dynamics computer simulations were carried out to investigate the dynamics of evaporation and condensation for argon at the temperature of 80 and 100 K. From the decrease of the survival probability of vapor molecules, the ratio of self reflection to collision is estimated to be 12%-15%, only weakly dependent on the temperature. This suggests that argon vapor molecules are in the condition of almost complete capture, and the condensation is considered to be a barrierless process. The total ratio of reflection which is evaluated with the flux correlation of condensation and evaporation is 20% at both temperature. The difference between these two ratios of reflection is ascribed to a phenomenon that vapor molecules colliding with the surface drive out other liquid molecules. This molecule exchange at the surface is as important as the self-reflection, and the conventional picture of condensation as a unimolecular chemical reaction is not appropriate.

  16. Performance of the TGT liquid argon calorimeter and trigger system

    International Nuclear Information System (INIS)

    A novel concept of a liquid argon calorimeter, the 'Thin Gap Turbine' (TGT) calorimeter, is presented. A TGT test module, equipped with specially developed cold front-end electronics in radiation hard GaAs technology, has been operated in a particle beam. Results on its performance are given. A 40 MHz FADC system with a 'circular data store' and standalone readout and playback capability has been developed to test the properties of the TGT detector for trigger purposes. Results on trigger efficiency, response and energy resolution are given. 12 refs., 21 figs., 6 tabs

  17. Optical fiber read-out for liquid argon scintillation light

    CERN Document Server

    Csáthy, J Janicskó; Kratz, J; Schönert, S; Wiesinger, Ch

    2016-01-01

    In this paper we describe the performance of a light detector for Ar scintillation light made of wavelength-shifting (WLS) fibers connected to Silicon-Photomultipliers (SiPM). The setup was conceived to be used as anti-Compton veto for high purity germanium (HPGe) detectors operated directly in liquid Argon (LAr). Background suppression efficiencies for different radioactive sources were measured in a test cryostat with about 800 kg LAr. This work was part of the R\\&D effort for the GERDA experiment.

  18. Searching for dark matter with single phase liquid argon

    Science.gov (United States)

    Caldwell, Thomas S., Jr.

    The first hint that we fail to understand the nature of a large fraction of the gravitating matter in the universe came from Fritz Zwicky's measurements of the velocity distribution of the Coma cluster in 1933. Using the Virial theorem, Zwicky found that galaxies in the cluster were orbiting far too fast to remain gravitationally bound when their mass was estimated by the brightness of the visible matter. This led to the postulation that some form of non-luminous dark matter is present in galaxies comprising a large fraction of the galactic mass. The nature of this dark matter remains yet unknown over 80 years after Zwicky's measurements despite the efforts of many experiments. Dark matter is widely believed to be a beyond the Standard Model particle which brings the dark matter problem into the realm of particle physics. Supersymmetry is one widely explored extension of the Standard model, from which particles meeting the constraints on dark matter properties can naturally arise. These particles are generically termed weakly interacting massive particles (WIMPs), and are a currently favored dark matter candidate. A variety of experimental efforts are underway aimed towards direct detection of dark matter through observation of rare scattering of WIMPs in terrestrial detectors. Single phase liquid argon detectors are an appealing WIMP detection technique due to the scintillation properties of liquid argon and the scalability of the single phase approach. The MiniCLEAN dark matter detector is a single phase liquid argon scintillation scintillation detector with a 500 kg active mass. The modular design offers 4pi coverage with 92 optical cassettes, each containing TPB coated acrylic and a cryogenic photomultiplier tube. The MiniCLEAN detector has recently completed construction at SNOLAB. The detector is currently being commissioned, and will soon begin operation with the liquid argon target. Utilizing advanced pulse-shape discrimination techniques, MiniCLEAN will

  19. Study of a Novel Concept for a Liquid Argon Calorimeter \

    CERN Multimedia

    2002-01-01

    % RD33 \\\\ \\\\ The development of a fast, highly granular and compact electromagnetic liquid argon calorimeter prototype is proposed as a generic R\\&D project for a novel concept of calorimetry in proton-proton and electron-positron collider detectors: the $^{\\prime$Thin Gap Turbine$^{\\prime}$ (TGT). The TGT calorimeter has a modular construction, is flexible in its longitudinal and transverse granularity, and offers a uniform energy response and resolution, independent of the production angle of incident particles. An important aspect of the project is the development of fast, radiation-hard front-end electronics which is operating in the cold.

  20. Study of a novel electromagnetic liquid argon calorimeter TGT

    International Nuclear Information System (INIS)

    The concept and the basic design of a fast, highly granular and compact electromagnetic liquid argon calorimeter are described. This novel calorimeter offers uniform energy response and constant energy resolution independent of the production angle of an impinging particle and of its impact position at the calorimeter. An example of a calorimeter with full rapidity coverage in an application in a collider detector is given. An important aspect of the concept is the electronics for fast signal processing matched to the short charge collection time. We report on the experience with the realization of a prototype calorimeter module and on its performance in a test beam exposure. 15 refs., 16 figs., 2 tabs

  1. Liquid argon scintillation read-out with silicon devices

    International Nuclear Information System (INIS)

    Silicon photosensors represent a viable alternative to standard photomultipliers in fields such as communications and medical imaging. We explored the interesting possibility of using these sensors in combination with liquid argon (LAr) for astroparticle physics applications such as neutrino, dark matter and double beta decay experiments. In fact, silicon photosensors have detection efficiencies comparable with those of the highest performance PMTs and can be manufactured with high level of radiopurity. In particular within the on-going R and D activity of the SILENT project (Low background and low noise techniques for double beta decay physics funded by ASPERA) a large area SiPM (Silicon PhotoMultiplier - Hamamatsu S11828-3344M - 1.7 cm2 area) has been installed in a LAr scintillation chamber of 0.5 liters volume together with a cryogenic photomultiplier tube (Hamamatsu R11065) used as a reference. The liquid argon chamber has been exposed to many gamma sources of different energies and single photoelectron response and light yield for the SiPM and PMT have been measured and compared. In this contribution the results of the tests, and the ongoing R and D to optimize the SiPM for cryogenic and for ultralow background applications, are reported, as well as the possible application in the GERDA experiment on Double Beta Decay Searches of 76Ge

  2. Liquid argon scintillation read-out with silicon devices

    Science.gov (United States)

    Canci, N.; Cattadori, C.; D'Incecco, M.; Lehnert, B.; Machado, A. A.; Riboldi, S.; Sablone, D.; Segreto, E.; Vignoli, C.

    2013-10-01

    Silicon photosensors represent a viable alternative to standard photomultipliers in fields such as communications and medical imaging. We explored the interesting possibility of using these sensors in combination with liquid argon (LAr) for astroparticle physics applications such as neutrino, dark matter and double beta decay experiments. In fact, silicon photosensors have detection efficiencies comparable with those of the highest performance PMTs and can be manufactured with high level of radiopurity. In particular within the on-going R&D activity of the SILENT project (Low background and low noise techniques for double beta decay physics funded by ASPERA) a large area SiPM (Silicon PhotoMultiplier - Hamamatsu S11828-3344M - 1.7 cm2 area) has been installed in a LAr scintillation chamber of 0.5 liters volume together with a cryogenic photomultiplier tube (Hamamatsu R11065) used as a reference. The liquid argon chamber has been exposed to many gamma sources of different energies and single photoelectron response and light yield for the SiPM and PMT have been measured and compared. In this contribution the results of the tests, and the ongoing R&D to optimize the SiPM for cryogenic and for ultralow background applications, are reported, as well as the possible application in the GERDA experiment on Double Beta Decay Searches of 76Ge.

  3. Large area liquid argon detectors for interrogation systems

    International Nuclear Information System (INIS)

    Measurements of the efficiency, pulse shape, and energy and time resolution of liquid argon (LAr) detectors are presented. Liquefied noble gas-based (LNbG) detectors have been developed for the detection of dark matter and neutrinoless double-beta decay. However, the same qualities that make LNbG detectors ideal for these applications, namely their size, cost, efficiency, pulse shape discrimination and resolution, make them promising for portal screening and the detection of Special Nuclear Materials (SNM). Two 18-liter prototype detectors were designed, fabricated, and tested, one with pure LAr and the other doped with liquid Xe (LArXe). The LArXe detector presented the better time and energy resolution of 3.3 ns and 20% at 662 KeV, respectively. The total efficiency of the detector was measured to be 35% with 4.5% of the total photons detected in the photopeak.

  4. ATLAS rewards two Japanese suppliers of major detector components.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The ATLAS supplier award in recognition of excellence has just been attributed to Kawasaki Heavy Industries, who produced the liquid-argon barrel cryostat. Kawasaki received its award in Hall 189 on the Meyrin site, where the cryostat is currently located. Toshiba Corporation's award for the superconducting central solenoid was presented two months ago at the Toshiba headquarters in Japan. Photo 01: P. Pailler, project leader for the ATLAS liquid-argon cryostats, addressing the Kawasaki delegation. Photo 04: H. Oberlack, project leader for the ATLAS liquid-argon system, addressing the Kawasaki delegation. Photo 11: P. Jenni (left), ATLAS Collaboration spokesperson, presenting the ATLAS supplier award for the barrel cryostat for the liquid-argon calorimeter to Mr. S. Nose, General Manager of Kawasaki Heavy Industries Ltd. Photo 18: J. Sondericker (left), liquid-argon barrel cryostat project engineer (BNL), presenting Mr. Nose (Kawasaki) an award from Brookhaven for the barrel cryostat for the ATLAS liquid-argo...

  5. A liquid argon scintillation veto for the GERDA experiment

    International Nuclear Information System (INIS)

    Gerda is an experiment to search for the neutrinoless double beta decay of 76Ge. Results of Phase I have been published in summer 2013. Currently Gerda is being upgraded to a second phase. To reach the aspired background index of ≤ 10-3 cts/(keV . kg . yr) for Phase II active background-suppression techniques will be applied, including an active liquid argon veto (LAr veto). It has been demonstrated by the LArGe test facility that the detection of argon scintillation light can be used to effectively suppress background events in the germanium, which simultaneously deposit energy in LAr. This talk focusses on the light instrumentation which is being installed in GERDA. Photomultiplier tubes (PMT) and wavelength-shifting fibers connected to silicon photomultipliers (SiPM) are combined to maximize the photoelectron-yield with respect to various background sources. Monte Carlo simulations have been performed to optimize the design for background suppression and low self-induced background. First results of the prototypes and the progress of installation are reported.

  6. A liquid argon scintillation veto for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Wegmann, Anne [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Collaboration: GERDA-Collaboration

    2014-07-01

    Gerda is an experiment to search for the neutrinoless double beta decay of {sup 76}Ge. Results of Phase I have been published in summer 2013. Currently Gerda is being upgraded to a second phase. To reach the aspired background index of ≤ 10{sup -3} cts/(keV . kg . yr) for Phase II active background-suppression techniques will be applied, including an active liquid argon veto (LAr veto). It has been demonstrated by the LArGe test facility that the detection of argon scintillation light can be used to effectively suppress background events in the germanium, which simultaneously deposit energy in LAr. This talk focusses on the light instrumentation which is being installed in GERDA. Photomultiplier tubes (PMT) and wavelength-shifting fibers connected to silicon photomultipliers (SiPM) are combined to maximize the photoelectron-yield with respect to various background sources. Monte Carlo simulations have been performed to optimize the design for background suppression and low self-induced background. First results of the prototypes and the progress of installation are reported.

  7. Study of electron recombination in liquid argon with the ICARUS TPC

    International Nuclear Information System (INIS)

    Electron recombination in liquid argon (LAr) is studied by means of charged particle tracks collected in various ICARUS liquid argon TPC prototypes. The dependence of the recombination on the particle stopping power has been fitted with a Birks functional dependence. The simulation of the process of electron recombination in Monte Carlo calculations is discussed. A quantitative comparison with previously published data is carried out

  8. Argon entrainment into liquid sodium in fast breeder reactor

    International Nuclear Information System (INIS)

    Highlights: ► In the present work, different types of entrainment mechanisms have been studied. ► Onset of entrainment could be characterized with turbulent intensities. ► For vortex type entrainment, a correlation has been proposed. - Abstract: Gas entrainment in pool type sodium cooled fast breeder reactors has been a subject of great interest for a quite long time now. The issue of entrainment of argon cover gas in LMFBR's is being addressed by fundamental studies. Present work focuses on characterization of onset of shear type entrainment and liquid fall type entrainment based on mean velocity and turbulent kinetic energy at liquid surface. Study also includes characterization of onset of vortex type entrainment based on mean velocities (time averaged) in the outlet pipe. Experiments were carried out to characterize shear type entrainment in stirred tank with different impeller geometries with air–water and xylene–water systems. Onset of liquid fall type entrainment was studied with cylindrical tank with a nozzle whose input angle varied. Mean and r.m.s. velocity profiles near the liquid surface were measured with the help of ultrasonic velocity profiler (UVP). The results are compared with other literature. It is observed that the onset of entrainment can be characterized by the turbulent kinetic energy near the free liquid surface. Re-submergence angle was measured and r.m.s. velocities found to be in the same range as in case of shear type of entrainment. Cylindrical tank with tangential inlet and bottom outlet was used to study onset of vortex formation. Effect of different parameters like outlet diameter, tank diameter and liquid height in the tank on critical velocity was studied and correlation has been proposed.

  9. First measurements with ARGONTUBE, a 5 m long drift Liquid Argon TPC

    International Nuclear Information System (INIS)

    The Liquid Argon Time Projection Chamber (LAr TPC) technique is a promising technology for future neutrino detectors. At LHEP of the University of Bern (Switzerland), an R and D program towards large detectors are on-going. The main goal is to show the feasibility of long drift paths over many meters. Therefore, a liquid Argon TPC with 5 m of drift distance was constructed. Many other aspects of the liquid Argon TPC technology are also investigated, such as a new device to generate high voltage in liquid Argon (Greinacher circuit), a recirculation filtering system and the multi-photon ionization of liquid Argon with a UV laser. Two detectors are built: a medium size prototype for specific detector technology studies, and ARGONTUBE, a 5 m long device

  10. Electron Neutrino Classification in Liquid Argon Time Projection Chamber Detector

    CERN Document Server

    Płoński, Piotr; Sulej, Robert; Zaremba, Krzysztof

    2015-01-01

    Neutrinos are one of the least known elementary particles. The detection of neutrinos is an extremely difficult task since they are affected only by weak sub-atomic force or gravity. Therefore large detectors are constructed to reveal neutrino's properties. Among them the Liquid Argon Time Projection Chamber (LAr-TPC) detectors provide excellent imaging and particle identification ability for studying neutrinos. The computerized methods for automatic reconstruction and identification of particles are needed to fully exploit the potential of the LAr-TPC technique. Herein, the novel method for electron neutrino classification is presented. The method constructs a feature descriptor from images of observed event. It characterizes the signal distribution propagated from vertex of interest, where the particle interacts with the detector medium. The classifier is learned with a constructed feature descriptor to decide whether the images represent the electron neutrino or cascade produced by photons. The proposed ap...

  11. Image Segmentation in Liquid Argon Time Projection Chamber Detector

    CERN Document Server

    Płoński, Piotr; Sulej, Robert; Zaremba, Krzysztof

    2015-01-01

    The Liquid Argon Time Projection Chamber (LAr-TPC) detectors provide excellent imaging and particle identification ability for studying neutrinos. An efficient and automatic reconstruction procedures are required to exploit potential of this imaging technology. Herein, a novel method for segmentation of images from LAr-TPC detectors is presented. The proposed approach computes a feature descriptor for each pixel in the image, which characterizes amplitude distribution in pixel and its neighbourhood. The supervised classifier is employed to distinguish between pixels representing particle's track and noise. The classifier is trained and evaluated on the hand-labeled dataset. The proposed approach can be a preprocessing step for reconstructing algorithms working directly on detector images.

  12. Photodegradation Mechanisms of Tetraphenyl Butadiene Coatings for Liquid Argon Detectors

    CERN Document Server

    Jones, B J P; Conrad, J M; Pla-Dalmau, A

    2013-01-01

    We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone (BP). We monitored the drop in performance and increase of benzophenone concentration in TPB plates with exposure to ultraviolet (UV) light, and demonstrate the correlation between these two variables. Based on the presence and initially exponential increase in the concentration of benzophenone observed, we propose that TPB degradation is a free radical-mediated photooxidation reaction, which is subsequently confirmed by displaying delayed degradation using a free radical inhibitor. Finally we show that the performance of wavelength-shifting coatings of the type envisioned for the LBNE experiment can be improved by 10-20%, with significantly delayed UV degradation, by using a 20% admixture of 4-tert-Butylcatechol.

  13. Photodegradation mechanisms of tetraphenyl butadiene coatings for liquid argon detectors

    Science.gov (United States)

    Jones, B. J. P.; VanGemert, J. K.; Conrad, J. M.; Pla-Dalmau, A.

    2013-01-01

    We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone. We monitored the drop in performance and increase of benzophenone concentration in TPB plates with exposure to ultraviolet (UV) light, and demonstrate the correlation between these two variables. Based on the presence and initially exponential increase in the concentration of benzophenone observed, we propose that TPB degradation is a free radical-mediated photooxidation reaction, which is subsequently confirmed by displaying delayed degradation using a free radical inhibitor. Finally we show that the performance of wavelength-shifting coatings of the type envisioned for the LBNE experiment can be improved by 10-20%, with significantly delayed UV degradation, by using a 20% admixture of 4-tert-Butylcatechol.

  14. Liquid Argon Cryogenic Detector Calibration by Inelastic Scattering of Neutrons

    CERN Document Server

    Polosatkin, Sergey; Dolgov, Alexander

    2014-01-01

    A method for calibration of cryogenic liquid argon detector response to recoils with certain energy -8.2 keV - is proposed. The method utilizes a process of inelastic scattering of monoenergetic neutrons produced by fusion DD neutron generator. Features of kinematics of inelastic scattering cause sufficient (forty times) increase in count rate of useful events relative to traditional scheme exploited elastic scattering with the same recoil energy and compatible energy resolution. The benefits of the proposed scheme of calibration most well implemented with the use of tagged neutron generator as a neutron source that allows to eliminate background originated from casual coincidence of signals on cryogenic detector and additional detector of scattered neutrons.

  15. The liquid argon TPC for the ICARUS experiment

    CERN Document Server

    Arneodo, F

    1997-01-01

    The ICARUS project aims at the realisation of a large liquid argon TPC to be run at the Underground Laboratories of Gran Sasso in Italy. An intense R&D; activity has put on firm grounds this new detector technology and experimentally confirmed its feasibility on a few ton scale. Based on these solid achievements, the collaboration is now confident of being able to build and safely operate a multi-kton detector. The reseach program of the experiment involves the systematic study of a wide spectrum of physical phenomena covering many orders of magnitude in the energy deposited in the detector: from the few MeV of solar neutrino interactions, to the about one GeV of the proton decay and atmospheric neutrinos, up to the higher energies of neutrinos from accelerators.

  16. Development of membrane cryostats for large liquid argon neutrino detectors

    CERN Document Server

    Montanari, D; Gendotti, A; Geynisman, M; Hentschel, S; Loew, T; Mladenov, D; Montanari, C; Murphy, S; Nessi, M; Norris, B; Noto, F; Rubbia, A; Sharma, R; Smargianaki, D; Stewart, J; Vignoli, C; Wilson, P; Wu, S

    2015-01-01

    A new collaboration is being formed to develop a multi-kiloton Long-Baseline neutrino experiment that will be located at the Surf Underground Research Facility (SURF) in Lead, SD. In the present design, the detector will be located inside cryostats filled with 68,400 ton of ultrapure liquid argon (less than 100 parts per trillion of oxygen equivalent contamination). To qualify the membrane technology for future very large-scale and underground implementations, a strong prototyping effort is ongoing: several smaller detectors of growing size with associated cryostats and cryogenic systems will be designed and built at Fermilab and CERN. They will take physics data and test different detector elements, filtration systems, design options and installation procedures. In addition, a 35 ton prototype is already operational at Fermilab and will take data with single-phase detector in early 2016. After the prototyping phase, the multi-kton detector will be constructed. After commissioning, it will detect and study ne...

  17. Photodegradation mechanisms of tetraphenyl butadiene coatings for liquid argon detectors

    International Nuclear Information System (INIS)

    We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone. We monitored the drop in performance and increase of benzophenone concentration in TPB plates with exposure to ultraviolet (UV) light, and demonstrate the correlation between these two variables. Based on the presence and initially exponential increase in the concentration of benzophenone observed, we propose that TPB degradation is a free radical-mediated photooxidation reaction, which is subsequently confirmed by displaying delayed degradation using a free radical inhibitor. Finally we show that the performance of wavelength-shifting coatings of the type envisioned for the LBNE experiment can be improved by 10-20%, with significantly delayed UV degradation, by using a 20% admixture of 4-tert-Butylcatechol.

  18. First measurement of the ionization yield of nuclear recoils in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, T. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Sangiorgio, Samuele [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Bernstein, A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Foxe, Michael P. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Hagmann, Chris [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Jovanovic, Igor [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Kazkaz, K. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Mozin, Vladimir V. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Norman, E. B. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Pereverzev, S. V. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Rebassoo, Finn O. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Sorensen, Peter F. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

    2014-05-01

    Liquid phase argon has long been used as a target medium for particle detection via scintillation light. Recently there has been considerable interest in direct detection of both hypothetical darkmatter particles and coherent elastic neutrino nucleus scattering. These as-yet unobserved neutral particle interactions are expected to result in a recoiling argon atom O(keV), generally referred to in the literature as a nuclear recoil. This prompts the question of the available electromagnetic signal in a liquid argon detector. In this Letter we report the first measurement of the ionization yield (Qy), detected electrons per unit energy, resulting from nuclear recoils in liquid argon, measured at 6.7 keV. This is also the lowest energy measurement of nuclear recoils in liquid argon.

  19. Simulation of the transition radiation detection conditions in the ATLAS TRT detector filled with argon and krypton gas mixtures

    International Nuclear Information System (INIS)

    Performance of the Transition Radiation Tracker (TRT) at the ATLAS experiment with argon and krypton gas mixtures was simulated. The efficiency of transition radiation registration, which is necessary for electron identification, was estimated along with the electron identification capabilities under such conditions

  20. Simulation of the transition radiation detection conditions in the ATLAS TRT detector filled with argon and krypton gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Boldyrev, A. S., E-mail: Alexey.Boldyrev@cern.ch [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Maevskiy, A. S., E-mail: Artem.Maevskiy@cern.ch [Moscow State University, Faculty of Physics (Russian Federation)

    2015-12-15

    Performance of the Transition Radiation Tracker (TRT) at the ATLAS experiment with argon and krypton gas mixtures was simulated. The efficiency of transition radiation registration, which is necessary for electron identification, was estimated along with the electron identification capabilities under such conditions.

  1. A dual type gridded ionization chamber as purity monitor of liquid argon

    International Nuclear Information System (INIS)

    The liquid argon time projection chamber (LATPC) is currently developed for detecting solar neutrons or proton decays. A dual type gripped ionization chamber with different drift distances of liberated electrons is constructed to measure the purity of liquid argon. A purification system of gaseous argon for LATPC with a drift space of about 150 cm is also constructed. The performances of both the dual type gripped ionization chamber and the purifier are tested seeking to develop a large scale LATPC. It is demonstrated that the attenuation length of electrons and also the impurity level in liquid argon can be well determined in the dual type gripped ionization chamber. In the case of the purifier, there still remains unknown low-level impurities in purified liquid argon. The results are compared with UCI data which were obtained with liquid argon mixed with water vapor. the same tendency is found in the attenuation length of their data as in the present results. This seems to suggest the dominant impurity remaining in the purifier is still water. The present apparatus was previously tested with liquid argon purified by other purification system of Ti-Ba getters. The attenuation length obtained by those tests was almost 100 cm. (N.K.)

  2. Dynamic range compression in a liquid argon calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, W.E. [Univ. of Pittsburgh, PA (United States); Lissauer, D.; Radeka, V.; Rescia, S.; Takai, H. [Brookhaven National Lab., Upton, NY (United States); Wingerter-Seez, I. [LAPP, Annecy-le-Vieux (France)

    1996-12-31

    The anticipated range of particle energies at the LHC, coupled with the need for precision, low noise calorimetry makes severe demands on the dynamic range of the calorimeter readout. A common approach to this problem is to use shapers with two or more gain scales. In this paper, the authors describe their experience with a new approach in which a preamplifier with dynamic gain compression is used. An unavoidable consequence of dynamic gain adjustment is that the peaking time of the shaper output signal becomes amplitude dependent. The authors have carried out a test of such a readout system in the RD3 calorimeter, a liquid argon device with accordion geometry. The calibration system is used to determine both the gain of the individual channels as well as to map the shape of the waveform as a function of signal amplitude. A new procedure for waveform analysis, in which the fitted parameters describe the impulse response of the system, permits a straightforward translation of the calibration waveform to the waveform generated by a particle crossing the ionization gap. They find that the linearity and resolution of the calorimeter is equivalent to that obtained with linear preamplifiers, up to an energy of 200 GeV.

  3. Scintillation Light from Cosmic-Ray Muons in Liquid Argon

    CERN Document Server

    Whittington, Denver

    2014-01-01

    This paper reports the results of the first experiment to directly measure the properties of the scintillation light generated by minimum ionizing cosmic-ray muons in liquid argon. Scintillation light from these muons is of value to studies of weakly-interacting particles in neutrino experiments and dark matter searches, as well as for particle identification. The experiment was carried out at the TallBo facility at Fermilab using prototype light guides and electronics developed for the Long-Baseline Neutrino Experiment. Analysis of the time-resolved structure of the scintillation light from cosmic-ray muons gives $\\langle \\tau_{\\text{T}}\\rangle = 1.43 \\pm 0.04~\\text{(stat.)} \\pm 0.007~\\text{(sys.)}~\\mu$s for the triplet light decay time constant. The ratio of singlet to triplet light measured using surface-coated light guides is $R = 0.39 \\pm 0.01~\\text{(stat.)} \\pm 0.008~\\text{(sys.)}$. There is some evidence that this value is not consistent with $R$ for minimum ionizing electrons. However, the value for $...

  4. Summary of the liquid argon calorimeter hermeticity working group

    International Nuclear Information System (INIS)

    The cryogenic nature, and hence the need to provide thermal insulation, of liquid argon calorimeters is known to pose serious problems for precise measurements of missing transverse energy, a key signature for new physics at the SSC. This problem is exacerbated by the central detector requirement of access to both sides of the detector. The original DiGiacomo et al. design sought to satisfy this access requirement and still minimize the effect of electromagnetic showers by protruding the end cap calorimeter into the central volume. This design was compared with two design variations by using a parameterization of hadronic and electromagnetic showers assuming no transverse width. These authors concluded that a flat head End Cap design was preferable to the original design for both electromagnetic and hadronic showers. The practical design advantages of this method was further demonstrated by the conclusions that instrumented calorimeter volumes which are not thick enough to absorb most of an electromagnetic shower before a dead volume enhance the resolution degradation. This means, for instance, that calorimeter modules should have their large eta edge on the front face beveled to decrease the effect of the structural washers separating the calorimeter module bays

  5. Energy resolution for 1 MeV electrons in liquid argon doped with allene

    International Nuclear Information System (INIS)

    The energy spectrum of conversion electrons (976 keV) from 207Bi has been measured by an ionization chamber filled with pure or allene-doped liquid argon. The collected charge in allene-doped liquid argon was increased compared to that in pure liquid argon. The resolution was not improved by doping liquid argon with allene in high electric fields, but it was improved in low fiels. This indicates that the recombination process is not a main cause of the observed resolutions. The best resolution was about 30 keV which is the same as the best value obtained so far. This is several times worse than the theoretical ultimate value based on the Fano factor. (orig.)

  6. Inside the ATLAS solenoid cryostat

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    Scientists are seen working on the inside of the ATLAS cryostat, which will be used to cool liquid argon to 90 K in the electromagnetic calorimeter. Thin lead plates immersed in the cooled liquid will produce electromagnetic showers of particles when an electron, positron or photon enter the detector. This causes the argon to glow, allowing the initial particle energy to be measured.

  7. Benchmarking TPB-coated Light Guides for Liquid Argon TPC Light Detection Systems

    OpenAIRE

    Baptista, B.; Bugel, L.; Chiu, C; Conrad, J. M.; Ignarra, C. M.; Jones, B. J. P.; Katori, T.; Mufson, S.

    2012-01-01

    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 (UV...

  8. Energy resolution for alpha particles in liquid argon doped with allene

    International Nuclear Information System (INIS)

    The charge response of liquid argon doped with small quantities of allene (C3H4) to α-particles has been studied. The addition of allene increased the amount of collected charge through photoionization and greatly improved the energy resolution of the incident α-particles. The noise subtracted resolution was 1.4% FWHM at the best with 4 ppm allene doped liquid argon. (orig.)

  9. A correction to Birks' Law in liquid argon ionization chamber simulations for highly ionizing particles

    International Nuclear Information System (INIS)

    We present a study of the performance of Birks' Law in liquid argon ionization chamber simulations as applied to highly ionizing particles, such as particles with multiple electric charges or with magnetic charge. We used Birks' Law to model recombination effects in a GEANT4 simulation of heavy ions in a liquid argon calorimeter. We then compared the simulation to published heavy-ion data to extract a highly ionizing particle correction to Birks' Law.

  10. Configurational Entropy,Diffusivity and Potential Energy Landscape in Liquid Argon

    Institute of Scientific and Technical Information of China (English)

    DUAN Yong-Ping; MA Cong-Xiao; LI Jia-Yun; LI Cong; WANG Dan; LI Mei-Li; SUN Min-Hua

    2009-01-01

    The configurational entropy, diffusion coefficient, dynamics and thermodynamics fragility indices of liquid argon are calculated using molecular dynamics simulations at two densities. The relationship between dynamics and thermodynamics properties is studied. The diffusion coefficient depends linearly on configurational entropy, which is consistent with the hypothesis of Adam-Gibbs. The consistence of dynamics and thermodynamics fragility indices demonstrates that dynamical behaviour is governed by thermodynamics behaviour in glass transition of liquid argon.

  11. LArGe: Background suppression using liquid argon (LAr) scintillation for 0$\

    CERN Document Server

    Marco, M D; Schönert, S

    2007-01-01

    Measurements with a bare p-type high purity germanium diode (HPGe) submerged in a 19 kg liquid argon (LAr) scintillation detector at MPIK Heidelberg are reported. The liquid argon--germanium system (LArGe) is operated as a 4$\\pi$ anti-Compton spectrometer to suppress backgrounds in the HPGe. This R&D is carried out in the framework of the GERDA experiment which searches for 0$\

  12. Scintillation light from cosmic-ray muons in liquid argon

    Science.gov (United States)

    Whittington, D.; Mufson, S.; Howard, B.

    2016-05-01

    This paper reports the results of an experiment to directly measure the time-resolved scintillation signal from the passage of cosmic-ray muons through liquid argon. Scintillation light from these muons is of value to studies of weakly-interacting particles in neutrino experiments and dark matter searches. The experiment was carried out at the TallBo dewar facility at Fermilab using prototype light guide detectors and electronics developed for the Deep Underground Neutrino Experiment. Two models are presented for the time structure of the scintillation light, a phenomenological model and a composite model. Both models find τT = 1.52 μs for the decay time constant of the Ar2* triplet state. These models also show that the identification of the ``early'' light fraction in the phenomenological model, FE ≈ 25% of the signal, with the total light from singlet decays is an underestimate. The total fraction of singlet light is FS ≈ 36%, where the increase over FE is from singlet light emitted by the wavelength shifter through processes with long decay constants. The models were further used to compute the experimental particle identification parameter Fprompt, the fraction of light coming in a short time window after the trigger compared with the light in the total recorded waveform. The models reproduce quite well the typical experimental value ~0.3 found by dark matter and double β-decay experiments, which suggests this parameter provides a robust metric for discriminating electrons and muons from more heavily ionizing particles.

  13. Scintillation light from cosmic-ray muons in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Whittington, Denver Wade [Indiana Univ., Bloomington, IN (United States). Physics Dept.; Mufson, S. [Indiana Univ., Bloomington, IN (United States). Astronomy Dept.; Howard, B. [Indiana Univ., Bloomington, IN (United States). Physics Dept.

    2016-05-01

    This paper reports the results of an experiment to directly measure the time-resolved scintillation signal from the passage of cosmic-ray muons through liquid argon. Scintillation light from these muons is of value to studies of weakly-interacting particles in neutrino experiments and dark matter searches. The experiment was carried out at the TallBo dewar facility at Fermilab using prototype light guide detectors and electronics developed for the Deep Underground Neutrino Experiment. Two models are presented for the time structure of the scintillation light, a phenomenological model and a physically-motivated model. Both models find tT = 1:52 ms for the decay time constant of the Ar 2 triplet state. These models also show that the identification of the “early” light fraction in the phenomenological model, FE 25% of the signal, with the total light from singlet decays is an underestimate. The total fraction of singlet light is FS 36%, where the increase over FE is from singlet light emitted by the wavelength shifter through processes with long decay constants. The models were further used to compute the experimental particle identification parameter Fprompt, the fraction of light coming in a short time window after the trigger compared with the light in the total recorded waveform. The models reproduce quite well the typical experimental value 0.3 found by dark matter and double b-decay experiments, which suggests this parameter provides a robust metric for discriminating electrons and muons from more heavily ionizing particles.

  14. Experimental Measurement for Shock Velocity-Mass Velocity Relationship of Liquid Argon Up to 46 GPa

    Institute of Scientific and Technical Information of China (English)

    孟川民; 施尚春; 董石; 杨向东; 谭华; 经福谦

    2003-01-01

    Shock properties of liquid argon were measured in the shock pressure up to 46 GPa by employing the two-stage light gas gun. Liquid nitrogen was used as coolant liquid. The cryogenic target system has been improved to compare with the previous work. Shock velocities were measured with self-shorting electrical probes. Impactor velocities were measured with an electrical-magnetic induction system. Mass velocities were obtained by mean of shock impedance matching method. The experimental data shows that the slope of experimental Hugoniot curve of liquid argon begins to decrease above 30 GPa.

  15. Operation of a GERDA phase I prototype detector in liquid argon and nitrogen

    International Nuclear Information System (INIS)

    A GERDA phase I prototype detector, consisting of a bare non-enriched high-purity (HP) p-type germanium diode mounted in a low mass holder has been operated both in liquid nitrogen and liquid argon. Because of its high density, liquid argon has been selected as cryogenic liquid and shield for GERDA experiment. The testing of this detector assembly has been carried out in the underground detector laboratory at LNGS, and at the detector manufacturer. The best resolution achieved is 2.2 keV FWHM at 1.332 MeV, which is the same as the resolution measured in a standard test cryostat. The long-term measurements with the prototype detector are performed in liquid argon. Up to now, 38 thermal cycles have been carried out with this detector. The operations, measurements and results of the prototype detector testing are summarized. (orig.)

  16. Results from a new combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter

    International Nuclear Information System (INIS)

    A new combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 10 to 300 GeV at an incident angle θ of about 12 deg. is well described by the expression σ/E=((41.9±1.6)%/√E+(1.8±0.1)%)+(1.8±0.1)/E, where E is in GeV. The response to electrons and muons was evaluated. Shower profiles, shower leakage and the angular resolution of hadronic showers were also studied. Results are compared with those from the previous beam test

  17. Results from a combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter

    CERN Document Server

    Ajaltouni, Ziad J; Alifanov, A; Amaral, P; Ambrosini, G; Amorim, A; Anderson, K J; Astvatsaturov, A R; Aubert, Bernard; Augé, E; Autiero, D; Azuelos, Georges; Badaud, F; Baisin, L; Battistoni, G; Bazan, A; Bee, C P; Bellettini, Giorgio; Berglund, S R; Berset, J C; Blaj, C; Blanchot, G; Blucher, E; Bogush, A A; Bohm, C; Boldea, V; Borisov, O N; Bosman, M; Bouhemaid, N; Brette, P; Bromberg, C; Brossard, M; Budagov, Yu A; Buono, S; Calôba, L P; Camin, D V; Canton, B; Casado, M P; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Chadelas, R; Chase, Robert L; Chekhtman, A; Chevaleyre, J C; Chevalley, J L; Chirikov-Zorin, I E; Chlachidze, G; Chollet, J C; Cobal, M; Cogswell, F; Colas, Jacques; Collot, J; Cologna, S; Constantinescu, S; Costa, G; Costanzo, D; Cozzi, L; Crouau, M; Dargent, P; Daudon, F; David, M; Davidek, T; Dawson, J; De, K; de La Taille, C; Del Prete, T; Depommier, P; de Saintignon, P; De Santo, A; Dinkespiler, B; Di Girolamo, B; Dita, S; Dolejsi, J; Dolezal, Z; Downing, R; Dugne, J J; Duval, P Y; Dzahini, D; Efthymiopoulos, I; Errede, D; Errede, S; Etienne, F; Evans, H; Fassnacht, P; Fedyakin, N N; Ferrari, A; Ferreira, P; Ferrer, A; Flaminio, Vincenzo; Fouchez, D; Fournier, D; Fumagalli, G; Gallas, E J; Gaspar, M; Gianotti, F; Gildemeister, O; Gingrich, D M; Glagolev, V V; Golubev, V B; Gómez, A; González, J; Gordon, H A; Grabskii, V; Hakopian, H H; Haney, M; Hellman, S; Henriques, A; Holmgren, S O; Honoré, P F; Hostachy, J Y; Huston, J; Ivanyushenkov, Yu M; Jézéquel, S; Johansson, E K; Jon-And, K; Jones, R; Juste, A; Kakurin, S; Karapetian, G V; Karyukhin, A N; Khokhlov, Yu A; Klioukhine, V I; Kolomoets, V; Kopikov, S V; Kostrikov, M E; Kovtun, V E; Kukhtin, V V; Kulagin, M; Kulchitskii, Yu A; Laborie, G; Lami, S; Lapin, V; Lebedev, A; Lefebvre, M; Le Flour, T; Leitner, R; León-Florián, E; Leroy, C; Le Van-Suu, A; Li, J; Liba, I; Linossier, O; Lokajícek, M; Lomakin, Yu F; Lomakina, O V; Lund-Jensen, B; Mahout, G; Maio, A; Malyukov, S N; Mandelli, L; Mansoulié, B; Mapelli, Livio P; Marin, C P; Marroquin, F; Martin, L; Mazzanti, M; Mazzoni, E; Merritt, F S; Michel, B; Miller, R; Minashvili, I A; Miotto, A; Miralles, L; Mnatzakanian, E A; Monnier, E; Montarou, G; Mornacchi, Giuseppe; Muanza, G S; Nagy, E; Némécek, S; Nessi, Marzio; Nicoleau, S; Noppe, J M; Olivetto, C; Orteu, S; Padilla, C; Pallin, D; Pantea, D; Parrour, G; Pereira, A; Perini, L; Perlas, J A; Pétroff, P; Pilcher, J E; Pinfold, James L; Poggioli, Luc; Poirot, S; Polesello, G; Price, L; Protopopov, Yu; Proudfoot, J; Pukhov, O; Radeka, V; Rahm, David Charles; Reinmuth, G; Renardy, J F; Renzoni, G; Resconi, S; Richards, R; Riu, I; Romanov, V; Ronceux, B; Rumyantsev, V; Rusakovitch, N A; Sala, P R; Sanders, H; Sauvage, G; Savard, P; Savoy-Navarro, Aurore; Sawyer, L; Says, L P; Schaffer, A C; Scheel, C V; Schwemling, P; Schindling, J; Seguin-Moreau, N; Seixas, J M; Selldén, B; Seman, M; Semenov, A A; Senchyshyn, V G; Serin, L; Shchelchkov, A S; Shevtsov, V P; Shochet, M J; Sidorov, V; Simaitis, V J; Simion, S; Sissakian, A N; Solodkov, A A; Sonderegger, P; Soustruznik, K; Stanek, R; Starchenko, E A; Stephani, D; Stephens, R; Studenov, S; Suk, M; Surkov, A; Tang, F; Tardell, S; Tas, P; Teiger, J; Teubert, F; Thaler, J J; Tisserant, S; Tokár, S; Topilin, N D; Trka, Z; Turcot, A S; Turcotte, M; Valkár, S; Vartapetian, A H; Vazeille, F; Vichou, I; Vinogradov, V; Vorozhtsov, S B; Vuillemin, V; Wagner, D; White, Alan R; Wingerter-Seez, I; Yamdagni, N; Yarygin, G; Yosef, C; Zaitsev, A; Zdrazil, M; Zitoun, R; Zolnierowski, Y

    1996-01-01

    The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300~GeV at an incident angle $\\theta$ of about 11$^\\circ$ is well-described by the expression $\\sigma/E = ((46.5 \\pm 6.0)\\%/\\sqrt{E} +(1.2 \\pm 0.3)\\%) \\oplus (3.2 \\pm 0.4)~\\mbox{GeV}/E$. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied.

  18. Results from a new combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter

    CERN Document Server

    Akhmadaliev, S Z; Amaral, P; Ambrosini, G; Amorim, A; Anderson, K; Andrieux, M L; Aubert, Bernard; Augé, E; Badaud, F; Baisin, L; Barreiro, F; Battistoni, G; Bazan, A; Bazizi, K; Bee, C P; Belorgey, J; Belymam, A; Benchekroun, D; Berglund, S R; Berset, J C; Blanchot, G; Bogush, A A; Bohm, C; Boldea, V; Bonivento, W; Borgeaud, P; Borisov, O N; Bosman, M; Bouhemaid, N; Breton, D; Brette, P; Bromberg, C; Budagov, Yu A; Burdin, S V; Calôba, L P; Camarena, F; Camin, D V; Canton, B; Caprini, M; Carvalho, J; Casado, M P; Cases, R; Castillo, M V; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Chadelas, R; Chalifour, M; Chekhtman, A; Chevalley, J L; Chirikov-Zorin, I E; Chlachidze, G; Chollet, J C; Citterio, M; Cleland, W E; Clément, C; Cobal, M; Cogswell, F; Colas, Jacques; Collot, J; Cologna, S; Constantinescu, S; Costa, G; Costanzo, D; Coulon, J P; Crouau, M; Dargent, P; Daudon, F; David, M; Davidek, T; Dawson, J; De, K; Delagnes, E; de La Taille, C; Del Peso, J; Del Prete, T; de Saintignon, P; Di Girolamo, B; Dinkespiler, B; Dita, S; Djama, F; Dodd, J; Dolejsi, J; Dolezal, Z; Downing, R; Dugne, J J; Duval, P Y; Dzahini, D; Efthymiopoulos, I; Errede, D; Errede, S; Etienne, F; Evans, H; Eynard, G; Farida, F; Fassnacht, P; Fedyakin, N N; Fernández de Troconiz, J; Ferrari, A; Ferrer, A; Flaminio, Vincenzo; Fournier, D; Fumagalli, G; Gallas, E J; García, G; Gaspar, M; Gianotti, F; Gildemeister, O; Glagolev, V; Glebov, V Yu; Gómez, A; González, V; González de la Hoz, S; Gordeev, A; Gordon, H A; Grabskii, V; Graugès-Pous, E; Grenier, P; Hakopian, H H; Haney, M; Hébrard, C; Henriques, A; Henry-Coüannier, F; Hervás, L; Higón, E; Holmgren, S O; Hostachy, J Y; Hoummada, A; Huet, M; Huston, J; Imbault, D; Ivanyushenkov, Yu M; Jacquier, Y; Jézéquel, S; Johansson, E K; Jon-And, K; Jones, R; Juste, A; Kakurin, S; Karst, P; Karyukhin, A N; Khokhlov, Yu A; Khubua, J I; Klioukhine, V I; Kolachev, G M; Kolomoets, V; Kopikov, S V; Kostrikov, M E; Kovtun, V E; Kozlov, V; Krivkova, P; Kukhtin, V V; Kulagin, M; Kulchitskii, Yu A; Kuzmin, M V; Labarga, L; Laborie, G; Lacour, D; Lami, S; Lapin, V; Le Dortz, O; Lefebvre, M; Le Flour, T; Leitner, R; Leltchouk, M; Le Van-Suu, A; Li, J; Liapis, C; Linossier, O; Lissauer, D; Lobkowicz, F; Lokajícek, M; Lomakin, Yu F; Lomakina, O V; López-Amengual, J M; Lottin, J P; Lund-Jensen, B; Lundqvist, J M; Maio, A; Makowiecki, D S; Malyukov, S N; Mandelli, L; Mansoulié, B; Mapelli, Livio P; Marin, C P; Marrocchesi, P S; Marroquin, F; Martin, L; Martin, O; Martin, P; Maslennikov, A M; Massol, N; Mazzanti, M; Mazzoni, E; Merritt, F S; Michel, B; Miller, R; Minashvili, I A; Miralles, L; Mirea, A; Mnatzakanian, E A; Monnier, E; Montarou, G; Mornacchi, Giuseppe; Mosidze, M D; Moynot, M; Muanza, G S; Nagy, E; Nayman, P; Némécek, S; Nessi, Marzio; Nicod, D; Nicoleau, S; Niculescu, M; Noppe, J M; Onofre, A; Pallin, D; Pantea, D; Paoletti, R; Park, I C; Parrour, G; Parsons, J; Pascual, J I; Pereira, A; Perini, L; Perlas, J A; Perrodo, P; Petroff, P; Pilcher, J E; Pinhão, J; Plothow-Besch, Hartmute; Poggioli, Luc; Poirot, S; Price, L; Protopopov, Yu; Proudfoot, J; Pukhov, O; Puzo, P; Radeka, V; Rahm, David Charles; Reinmuth, G; Renardy, J F; Renzoni, G; Rescia, S; Resconi, S; Richards, R; Richer, J P; Riu, I; Roda, C; Roldán, J; Romance, J B; Romanov, V; Romero, P; Rusakovitch, N A; Sala, P R; Sanchis, E; Sanders, H; Santoni, C; Santos, J; Sauvage, D; Sauvage, G; Savoy-Navarro, Aurore; Sawyer, L; Says, L P; Schaffer, A C; Schwemling, P; Schwindling, J; Seguin-Moreau, N; Seidl, W; Seixas, J M; Selldén, B; Seman, M; Semenov, A A; Senchyshyn, V G; Serin, L; Shaldaev, E; Shchelchkov, A S; Shochet, M J; Sidorov, V; Silva, J; Simaitis, V J; Simion, S; Sissakian, A N; Soloviev, I V; Snopkov, R; Söderqvist, J; Solodkov, A A; Sonderegger, P; Soustruznik, K; Spanó, F; Spiwoks, R; Stanek, R; Starchenko, E A; Stavina, P; Stephens, R; Studenov, S; Suk, M; Surkov, A; Sykora, I; Taguet, J P; Takai, H; Tang, F; Tardell, S; Tas, P; Teiger, J; Teubert, F; Thaler, J J; Thion, J; Tikhonov, Yu A; Tisserand, V; Tisserant, S; Tokar, S; Topilin, N D; Trka, Z; Turcotte, M; Valkár, S; Varanda, M J; Vartapetian, A H; Vazeille, F; Vichou, I; Vincent, P; Vinogradov, V; Vorozhtsov, S B; Vuillemin, V; Walter, C; White, A; Wielers, M; Wingerter-Seez, I; Wolters, H; Yamdagni, N; Yarygin, G; Yosef, C; Zaitsev, A; Zitoun, R; Zolnierowski, Y

    2000-01-01

    A new combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 10 to 300 GeV at an incident angle theta of about 12 degrees is well described by the expression sigma /E=((41.9+or-1.6)%/ square root E+(1.8+or-0.1)%)(+) (1.8+or-0.1)/E, where E is in GeV. The response to electrons and muons was evaluated. Shower profiles, shower leakage and the angular resolution of hadronic showers were also studied. Results are compared with those from the previous beam test. (22 refs).

  19. Results from the Bo Liquid Argon Scintillation Test Stand at Fermilab

    International Nuclear Information System (INIS)

    In these proceedings I discuss results from the Bo test stand at the Proton Assembly Building, Fermilab. This test stand has been used to characterize elements of the MicroBooNE optical system as well as to perform studies of processes affecting argon scintillation light such as scintillation quenching and optical absorption by impurities. I review in detail a recent measurement of the absorption of liquid argon scintillation light by dissolved nitrogen at the part-per-million level

  20. TPB-coated Light Guides for Liquid Argon TPC Light Detection Systems

    CERN Document Server

    Ignarra, C M

    2013-01-01

    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.

  1. TPB-coated light guides for liquid argon TPC light detection systems

    Science.gov (United States)

    Ignarra, C. M.

    2013-10-01

    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.

  2. Improved TPB-coated light guides for liquid argon TPC light detection systems

    International Nuclear Information System (INIS)

    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 guides for future LArTPCs. Improvements come from using a new acrylic-based coating, diamond-polished cast UV transmitting acrylic bars, and a hand-dipping technique to coat the bars. We discuss a model for connecting bar response in air to response in liquid argon and compare this to data taken in liquid argon. The good agreement between the prediction of the model and the measured response in liquid argon demonstrates that characterization in air is sufficient for quality control of bar production. This model can be used in simulations of light guides for future experiments

  3. Improved TPB-coated light guides for liquid argon TPC light detection systems

    Science.gov (United States)

    Moss, Z.; Bugel, L.; Collin, G.; Conrad, J. M.; Jones, B. J. P.; Moon, J.; Toups, M.; Wongjirad, T.

    2015-08-01

    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 guides for future LArTPCs. Improvements come from using a new acrylic-based coating, diamond-polished cast UV transmitting acrylic bars, and a hand-dipping technique to coat the bars. We discuss a model for connecting bar response in air to response in liquid argon and compare this to data taken in liquid argon. The good agreement between the prediction of the model and the measured response in liquid argon demonstrates that characterization in air is sufficient for quality control of bar production. This model can be used in simulations of light guides for future experiments.

  4. Studies with a liquid argon time projection chamber. Addressing technological challenges of large-scale detectors

    International Nuclear Information System (INIS)

    Michael Schenk evaluates new technologies and methods, such as cryogenic read-out electronics and a UV laser system, developed to optimise the performance of large liquid argon time projection chambers (LArTPC). Amongst others, the author studies the uniformity of the electric field produced by a Greinacher high-voltage generator operating at cryogenic temperatures, measures the linear energy transfer (LET) of muons and the longitudinal diffusion coefficient of electrons in liquid argon. The results are obtained by analysing events induced by cosmic-ray muons and UV laser beams. The studies are carried out with ARGONTUBE, a prototype LArTPC in operation at the University of Bern, Switzerland, designed to investigate the feasibility of drift distances of up to five metres for electrons in liquid argon.

  5. Operation of a high purity germanium crystal in liquid argon as a Compton suppressed radiation spectrometer

    CERN Document Server

    Orrell, J L; Amsbaugh, J F; Doe, P J; Hossbach, T W; Orrell, John L.; Aalseth, Craig E.; Amsbaugh, John F.; Doe, Peter J.; Hossbach, Todd W.

    2007-01-01

    A high purity germanium crystal was operated in liquid argon as a Compton suppressed radiation spectrometer. Spectroscopic quality resolution of less than 1% of the full-width half maximum of full energy deposition peaks was demonstrated. The construction of the small apparatus used to obtain these results is reported. The design concept is to use the liquid argon bath to both cool the germanium crystal to operating temperatures and act as a scintillating veto. The scintillation light from the liquid argon can veto cosmic-rays, external primordial radiation, and gamma radiation that does not fully deposit within the germanium crystal. This technique was investigated for its potential impact on ultra-low background gamma-ray spectroscopy. This work is based on a concept initially developed for future germanium-based neutrinoless double-beta decay experiments.

  6. The ATLAS solenoid approaches its final position

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The ATLAS superconducting solenoid during one of the transport operations. Securely attached to the overhead crane, the solenoid is situated in front of the opening to the liquid-argon electromagnetic calorimeter, where it will soon be inserted.

  7. ATLAS Solenoid placed in its final position

    CERN Multimedia

    2004-01-01

    The ATLAS superconducting solenoid during one of the transport operations. Securely attached to the overhead crane, the solenoid is situated in front of the opening to the liquid-argon electromagnetic calorimeter, where it will soon be inserted.

  8. The ArDM, a ton-scale liquid argon experiment for direct dark matter detection

    International Nuclear Information System (INIS)

    Full text: The ArDM is a 1-ton liquid argon based experiment which aims at the direct detection of Weakly Interacting Massive Particles (WIMPs). The detector is sensitive to the small signals of scintillation light and the ionization charge independently. The sufficient discrimination between nuclear recoils and the background is possible by the ratio of scintillation to ionization and by the different time structure of the scintillation. In the present time the experiment is under construction at CERN. The detector was recently tested being fully filled with Liquid Argon. Promising results on the light yield and on the detector performance were obtained. (author)

  9. Operation of a GERDA phase I prototype detector in liquid argon

    International Nuclear Information System (INIS)

    A non-enriched high-purity (HP) p-type germanium diode has been operated in a low mass holder in liquid nitrogen and liquid argon. Because of the shielding and scintillation properties of liquid argon, GERDA experiment is planned to use it as a cryogenic fluid shield. Therefore, the long-term measurements with the bare detector are performed in liquid argon. The testing of the prototype detector and the preparation of the enriched detectors for GERDA phase I are being carried out in the GERDA underground Detector Laboratory (GDL) at LNGS. The phase I prototype detector assembly is being operated since beginning of 2006 to study detector handling protocols, detector assembly performance and detector assembly stability. 45 warming and cooling cyclings have been carried out. Since February 8 2007, the prototype detector is continuously operated in liquid argon under varying irradiation conditions. The operations, measurements and results of the prototype detector testing as well as the status of the phase I enriched detectors are summarized

  10. A dual type gridded ionization chamber as liquid argon purity monitor II

    International Nuclear Information System (INIS)

    The attenuation lengths of electrons in liquid argon purified by molecular sieves, a Ti-Ba getter and an Oxysorb filter was measured by using a dual type gridded ionization chamber. From the electric field dependence of the attenuation length, it is concluded that the type of remaining impurity is not an oxygen type, but N2O type. (author)

  11. Liquid Argon Dielectric Breakdown Studies with the MicroBooNE Purification System

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, R. [Fermilab; Carls, B. [Fermilab; James, C. [Fermilab; Johnson, B. [Fermilab; Jostlein, H. [Fermilab; Lockwitz, S. [Fermilab; Lundberg, B. [Fermilab; Raaf, J. L. [Fermilab; Rameika, R. [Fermilab; Rebel, B. [Fermilab; Zeller, G. P. [Fermilab; Zuckerbrot, M. [Fermilab

    2014-11-04

    The proliferation of liquid argon time projection chamber detectors makes the characterization of the dielectric properties of liquid argon a critical task. To improve understanding of these properties, a systematic study of the breakdown electric field in liquid argon was conducted using a dedicated cryostat connected to the MicroBooNE cryogenic system at Fermilab. An electrode sphere-plate geometry was implemented using spheres with diameters of 1.3 mm, 5.0 mm, and 76 mm. The MicroBooNE cryogenic system allowed measurements to be taken at a variety of electronegative contamination levels ranging from a few parts-per-million to tens of parts-per-trillion. The cathode-anode distance was varied from 0.1 mm to 2.5 cm. The results demonstrate a geometric dependence of the electric field strength at breakdown. This study is the first time that the dependence of the breakdown field on stressed cathode area has been shown for liquid argon.

  12. Ionization EM calorimetry with accordion electrodes and liquid krypton or argon

    Energy Technology Data Exchange (ETDEWEB)

    Radeka, V.

    1993-11-01

    The results of a study and tests of a liquid krypton/argon electromagnetic calorimeter with accordion electrode structure are briefly summarized. This includes the calorimeter response to electrons and muons, energy, pointing and timing resolution, and a measurement by multiple sampling. The electrode layout with fine segmentation is illustrated.

  13. Test beam results of a stereo preshower integrated in the liquid argon accordion calorimeter

    CERN Document Server

    Davis, R; Greenious, G; Kitching, P; Olsen, B; Pinfold, James L; Rodning, N L; Boos, E; Zhautykov, B O; Aubert, Bernard; Bazan, A; Beaugiraud, B; Boniface, J; Colas, Jacques; Eynard, G; Jézéquel, S; Le Flour, T; Linossier, O; Nicoleau, S; Sauvage, G; Thion, J; Van den Plas, D; Wingerter-Seez, I; Zitoun, R; Zolnierowski, Y; Chmeissani, M; Fernández, E; Garrido, L; Martínez, M; Padilla, C; Citterio, M; Gordon, H A; Lissauer, D; Ma, H; Makowiecki, D S; Radeka, V; Rahm, David Charles; Rescia, S; Stephani, D; Takai, H; Baisin, L; Berset, J C; Chevalley, J L; Gianotti, F; Gildemeister, O; Marin, C P; Nessi, Marzio; Poggioli, Luc; Richter, W; Vuillemin, V; Baze, J M; Delagnes, E; Gosset, L G; Lavocat, P; Lottin, J P; Mansoulié, B; Meyer, J P; Renardy, J F; Schwindling, J; Simion, S; Taguet, J P; Teiger, J; Walter, C; Collot, J; de Saintignon, P; Hostachy, J Y; Mahout, G; Barreiro, F; Del Peso, J; García, J; Hervás, L; Labarga, L; Romero, P; Scheel, C V; Chekhtman, A; Cousinou, M C; Dargent, P; Dinkespiler, B; Etienne, F; Fassnacht, P; Fouchez, D; Martin, L; Miotto, A; Monnier, E; Nagy, E; Olivetto, C; Tisserant, S; Battistoni, G; Camin, D V; Cavalli, D; Costa, G; Cozzi, L; Fedyakin, N N; Ferrari, A; Mandelli, L; Mazzanti, M; Perini, L; Resconi, S; Sala, P R; Beaudoin, G; Depommier, P; León-Florián, E; Leroy, C; Roy, P; Augé, E; Breton, D; Chase, Robert L; Chollet, J C; de La Taille, C; Fayard, Louis; Fournier, D; González, J; Hrisoho, A T; Jacquier, Y; Merkel, B; Nikolic, I A; Noppe, J M; Parrour, G; Pétroff, P; Puzo, P; Richer, J P; Schaffer, A C; Seguin-Moreau, N; Serin, L; Tisserand, V; Veillet, J J; Vichou, I; Canton, B; David, J; Genat, J F; Imbault, D; Le Dortz, O; Savoy-Navarro, Aurore; Schwemling, P; Eek, L O; Lund-Jensen, B; Söderqvist, J; Astbury, Alan; Keeler, Richard K; Lefebvre, M; Robertson, S; White, J

    1998-01-01

    This paper describes the construction of an integrated preshower within the RD3 liquid argon accordion calorimeter. It has a stereo view which enables the measurement of two transverse coordinates. The prototype was tested at CERN with electrons, photons and muons to validate its capability to work at LHC ( Energy resolution, impact point resolution, angular resolution, $\\pi^o$/$\\gamma$ rejection ).

  14. Liquid Argon Dielectric Breakdown Studies with the MicroBooNE Purification System

    CERN Document Server

    Acciarri, R; James, C; Johnson, B; Jostlein, H; Lockwitz, S; Lundberg, B; Raaf, J L; Rameika, R; Rebel, B; Zeller, G P; Zuckerbrot, M

    2014-01-01

    The proliferation of liquid argon time projection chamber detectors makes the characterization of the dielectric properties of liquid argon a critical task. To improve understanding of these properties, a systematic study of the breakdown electric field in liquid argon was conducted using a dedicated cryostat connected to the MicroBooNE cryogenic system at Fermilab. An electrode sphere-plate geometry was implemented using spheres with diameters of 1.3 mm, 5.0 mm, and 76 mm. The MicroBooNE cryogenic system allowed measurements to be taken at a variety of electronegative contamination levels ranging from a few parts-per-million to tens of parts-per- trillion. The cathode-anode distance was varied from 0.1 mm to 2.5 cm. The results demonstrate a geometric dependence of the electric field strength at breakdown. This study is the first time that the dependence of the breakdown field on stressed cathode area has been shown for liquid argon.

  15. Performance of VUV-sensitive MPPC for Liquid Argon Scintillation Light

    OpenAIRE

    Igarashi, T; Naka, S.; Tanaka, M.; Washimi, T.; Yorita, K.

    2015-01-01

    A new type of the Multi-Pixel Photon Counter (MPPC), sensitive to Vacuum Ultra-Violet (VUV) light (wavelength {\\lambda} < 150 nm), is recently developed and produced by Hamamatsu Photonics K.K. The basic properties of the new MPPC are measured at cryogenic facility of Waseda university using liquid nitrogen. Temperature dependence of breakdown voltage, capacitance, and dark count rate of the MPPC are also evaluated. In addition, the absolute photon detection efficiency (PDE) for liquid argon ...

  16. Demonstration and Comparison of Operation of Photomultiplier Tubes at Liquid Argon Temperature

    OpenAIRE

    Acciarri, R.; Antonello, M.; Boffelli, F.; Cambiaghi, M.; Canci, N.; Cavanna, F.; Cocco, A. G.; Deniskina, N.; Di Pompeo, F.; Fiorillo, G.; Galbiati, C.; Grandi, L.; Kryczynski, P.; Meng, G.; Montanari, C.

    2011-01-01

    Liquified noble gases are widely used as a target in direct Dark Matter searches. Signals from scintillation in the liquid, following energy deposition from the recoil nuclei scattered by Dark Matter particles (e.g. WIMPs), should be recorded down to very low energies by photosensors suitably designed to operate at cryogenic temperatures. Liquid Argon based detectors for Dark Matter searches currently implement photo multiplier tubes for signal read-out. In the last few years PMTs with photoc...

  17. Table-top setup for investigating the scintillation properties of liquid argon

    CERN Document Server

    Heindl, T; Fedenev, A; Hofmann, M; Krücken, R; Oberauer, L; Potzel, W; Wieser, J; Ulrich, A

    2015-01-01

    The spectral and temporal light emission properties of liquid argon have been studied in the context of its use in large liquid rare-gas detectors for detecting Dark Matter particles in astronomy. A table-top setup has been developed. Continuous and pulsed low energy electron beam excitation is used to stimulate light emission. A spectral range from 110 to 1000 nm in wavelength is covered by the detection system with a time resolution on the order of 1 ns.

  18. High-Temperature Superconducting Level Meter for Liquid Argon Detectors

    CERN Document Server

    Bueno, A; Navarro, J L; Navas, S; Ruiz, A G

    2008-01-01

    Capacitive devices are customarily used as probes to measure the level of noble liquids in detectors operated for neutrino studies and dark matter searches. In this work we describe the use of a high-temperature superconducting material as an alternative to control the level of a cryogenic noble liquid. Lab measurements indicate that the superconductor shows a linear behaviour, a high degree of stability and offers a very accurate determination of the liquid volume. This device is therefore a competitive instrument and shows several advantages over conventional level meters.

  19. A 20-Liter Test Stand with Gas Purification for Liquid Argon Research

    CERN Document Server

    Li, Yichen; Tang, Wei; Joshi, Jyoti; Qian, Xin; Diwan, Milind; Kettell, Steve; Morse, William; Rao, Triveni; Stewart, James; Tsang, Thomas; Zhang, Lige

    2016-01-01

    We describe the design of a 20-liter test stand constructed to study fundamental properties of liquid argon (LAr). This system utilizes a simple, cost-effective gas argon (GAr) purification to achieve ultra-high purity, which is necessary to study electron transport properties in LAr. An electron drift stack with up to 25 cm length is constructed to study electron drift, diffusion, and attachment at various electric fields. A gold photocathode and a pulsed laser are used as a bright electron source. The operational performance of this system is reported.

  20. Evaporation characteristics of thin film liquid argon in nano-scale confinement: A molecular dynamics study

    Science.gov (United States)

    Hasan, Mohammad Nasim; Shavik, Sheikh Mohammad; Rabbi, Kazi Fazle; Haque, Mominul

    2016-07-01

    Molecular dynamics simulation has been carried out to explore the evaporation characteristics of thin liquid argon film in nano-scale confinement. The present study has been conducted to realize the nano-scale physics of simultaneous evaporation and condensation inside a confined space for a three phase system with particular emphasis on the effect of surface wetting conditions. The simulation domain consisted of two parallel platinum plates; one at the top and another at the bottom. The fluid comprised of liquid argon film at the bottom plate and vapor argon in between liquid argon and upper plate of the domain. Considering hydrophilic and hydrophobic nature of top and bottom surfaces, two different cases have been investigated: (i) Case A: Both top and bottom surfaces are hydrophilic, (ii) Case B: both top and bottom surfaces are hydrophobic. For all cases, equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. Then the lower wall was set to four different temperatures such as 110 K, 120 K, 130 K and 140 K to perform non-equilibrium molecular dynamics (NEMD). The variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat fluxes normal to top and bottom walls were estimated and discussed to illuminate the effectiveness of heat transfer in both hydrophilic and hydrophobic confinement at various boundary temperatures of the bottom plate.

  1. Atomistic Simulation of Properties of Ultra-thin Layer of Liquid Argon Compressed Between Diamond Surfaces

    Directory of Open Access Journals (Sweden)

    A.V. Khomenko

    2016-03-01

    Full Text Available Using the method of classical molecular dynamics we investigate the properties of ultrathin film of liquid argon, which consists of one or two layers of molecules and is confined by two atomically smooth crystalline diamond surfaces. The aim of the research is validating the use of rigid surfaces and one of the available models of the argon molecule. We study the behavior of the equilibrium and dynamic characteristics of the system. It is shown that at increasing external load the transition of film in the solid-like state occurs, which is indicated by the behavior of the velocity autocorrelation function of argon molecules, reduction of the magnitude of the diffusion coefficient and the shear viscosity increase. The organization of molecules in layers and the presence of their in-plane ordering are revealed. The dependences of the kinetic friction force on time and load are obtained. The results are compared with experimental data.

  2. Performance of bare high-purity germanium detectors in liquid argon for the GERDA experiment

    CERN Document Server

    Heider, Marik Barnabé; Chkvorets, Oleg; Di Vacri, Assunta; Gusev, Konstantin; Schönert, Stefan; Shirchenko, Mark

    2008-01-01

    The GERmanium Detector Array, GERDA, will search for neutrinoless double beta decay in 76Ge at the National Gran Sasso Laboratory of the INFN. Bare high-purity germanium detectors enriched in 76Ge will be submerged in liquid argon serving simultaneously as a shield against external radioactivity and as a cooling medium. In GERDA Phase-I, reprocessed enriched-Ge detectors, which were previously operated by the Heidelberg-Moscow and IGEX collaborations, will be redeployed. Before operating the enriched detectors, tests are performed with non-enriched bare HPGe detectors in the GERDA underground Detector Laboratory to test the Phase-I detector assembly, the detector handling protocols, the refurbishment technology and to study the long-term stability in liquid argon. The leakage currents in liquid argon and liquid nitrogen have been extensively studied under varying gamma irradiation conditions. In total three non-enriched high-purity p-type prototype germanium detectors have been operated successfully. The dete...

  3. Demonstration and Comparison of Operation of Photomultiplier Tubes at Liquid Argon Temperature

    CERN Document Server

    Acciarri, R; Boffelli, F; Cambiaghi, M; Canci, N; Cavanna, F; Cocco, A G; Di Pompeo, F; Fiorillo, G; Galbiati, C; Grandi, L; Kryczynski, P; Meng, G; Montanari, C; Palamara, O; Pandola, L; Perfetto, F; Mortari, G B Piano; Pietropaolo, F; Raselli, G L; Rossella, M; Rubbia, C; Segreto, E; Szelc, A M; Triossi, A; Ventura, S; Vignoli, C; Zani, A

    2011-01-01

    Liquified noble gases are widely used as a target in direct Dark Matter searches. Signals from scintillation in the liquid, following energy deposition from the recoil nuclei scattered by Dark Matter particles (e.g. WIMPs), should be recorded down to very low energies by photosensors suitably designed to operate at cryogenic temperatures. Liquid Argon based detectors for Dark Matter searches currently implement photo multiplier tubes for signal read-out. In the last few years PMTs with photocathodes operating down to liquid Argon temperatures (87 K) have been specially developed with increasing Quantum Efficiency characteristics. The most recent of these, Hamamatsu Photonics Mod. R11065 with peak QE up to about 35%, has been extensively tested within the R&D program of the WArP Collaboration. During these testes the Hamamatsu PMTs showed superb performance and allowed obtaining a light yield around 7 phel/keVee in a Liquid Argon detector with a photocathodic coverage in the 12% range, sufficient for detec...

  4. Radon backgrounds in the DEAP-1 liquid argon based Dark Matter detector

    CERN Document Server

    Amaudruz, P -A; Beltran, B; Boudjemline, K; Caldwell, M G Boulay B Cai T; Chen, M; Chouinard, R; Cleveland, B T; Contreras, D; Dering, K; Duncan, F; Ford, R; Giuliani, R Gagnon F; Golovko, M Gold V V; Gorel, P; Graham, K; Grant, D R; Hakobyan, R; Hallin, A L; Harvey, P; Hearns, C; Jillings, C J; Kuźniak, M; Lawson, I; Li, O; Lidgard, J; Liimatainen, P; Lippincott, W H; Mathew, R; McDonald, A B; McElroy, T; McFarlane, K; McKinsey, D; Muir, A; Nantais, C; Nicolics, K; Nikkel, J; Noble, T; O'Dwyer, E; Olsen, K S; Ouellet, C; Pasuthip, P; Pollmann, T; Rau, W; Retiere, F; Ronquest, M; Skensved, P; Sonley, T; Vázquez-Jáuregui, E; Veloce, L; Ward, M

    2012-01-01

    The DEAP-1 \\SI{7}{kg} single phase liquid argon scintillation detector was operated underground at SNOLAB in order to test the techniques and measure the backgrounds inherent to single phase detection, in support of the DEAP-3600 Dark Matter detector. Backgrounds in DEAP are controlled through material selection, construction techniques, pulse shape discrimination and event reconstruction. This report details the analysis of background events observed in three iterations of the DEAP-1 detector, and the measures taken to reduce them. The $^{222}$Rn decay rate in the liquid argon was measured to be between 16 and \\SI{26}{\\micro\\becquerel\\per\\kilogram}. We found that the background spectrum near the region of interest for Dark Matter detection in the final DEAP-1 detector generation is well described considering events from three sources: radon daughters decaying on the surface of the active volume, the expected rate of electromagnetic events misidentified as nuclear recoils due to inefficiencies in the pulse sh...

  5. Experimental study of electric breakdowns in liquid argon at centimeter scale

    CERN Document Server

    Blatter, A; Hsu, C -C; Janos, S; Kreslo, I; Luethi, M; von Rohr, C Rudolf; Schenk, M; Strauss, T; Weber, M S; Zeller, M

    2014-01-01

    In this paper we present results on measurements of the dielectric strength of liquid argon near its boiling point and cathode-anode distances in the range of 0.1 mm to 40 mm with spherical cathode and plane anode. We show that at such distances the applied electric field at which breakdowns occur is as low as 40 kV/cm. Flash-overs across the ribbed dielectric of the high voltage feed-through are observed for a length of 300 mm starting from a voltage of 55 kV. These results contribute to set reference for the breakdown-free design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).

  6. First results obtained from the Cello liquid argon end cap calorimeters

    International Nuclear Information System (INIS)

    The Cello liquid argon calorimeter is presented in the first part of this thesis. The cryogenic system has to supply three cryostats filled with liquid argon: one cylindrical cryostat of 25 m3 volume contains 2x8 separate modules; each of the two symmetric end cap cryostats contains two half cylindrical modules. Each module in the end cap part consists of 42 layers of lead strips interleaved with 43 full plates. The strips are alternatively vertical, horizontal and circular. In front of the lead calorimeter are 4 planes of copper foils glued on epoxy for dE/dx measurement. The electronics, signal processing and data acquisition system are described. In the second part, the performance and analysis of data measured by the end cap calorimeters are reported: study of Bhabha scattering e+e- → e+e-; preliminary results obtained in two photon physics e+e- → e+e-γγ → e+e-X

  7. Benchmarking TPB-coated Light Guides for Liquid Argon TPC Light Detection Systems

    CERN Document Server

    Baptista, B; Chiu, C; Conrad, J M; Ignarra, C M; Jones, B J P; Katori, T; Mufson, S

    2012-01-01

    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 factor of three higher light yield than has been previously reported from lightguides. This paper provides information on the response of the lightguides so that these can be modeled in simulations for future LArTPCs. This paper also identifies areas of R&D for potential improvements in the lightguide response

  8. Improved TPB-coated Light Guides for Liquid Argon TPC Light Detection Systems

    CERN Document Server

    Moss, Z; Collin, G; Conrad, J M; Jones, B J P; Moon, J; Toups, M; Wongjirad, T

    2014-01-01

    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 tetra phenyl 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 guides for future LArTPCs. Improvements come from using a new acrylic-based coating, diamond-polished cast UV transmitting acrylic bars, and a hand-dipping technique to coat the bars.

  9. An accordion liquid argon electromagnetic calorimeter with absorber in all electrodes

    International Nuclear Information System (INIS)

    A prototype electromagnetic liquid argon calorimeter with accordion geometry, using absorber material in all electrodes, has been constructed and tested. This construction results in twice the sampling frequency compared to the conventional accordion electrode structure. The energy resolution, measured with 15 GeV electrons, was found to be 6.3%/√(E), in good agreement with the value expected from Monte Carlo simulations. ((orig.))

  10. A measurement of E/. pi. for a fast lead liquid argon calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Makowiecki, D.; Gordon, H.A.; Ma, H.; Murtagh, M.; Radeka, V.; Rahm, D.; Rescia, S. (Brookhaven National Lab., Upton, NY (United States)); Abrams, G.S.; Groom, D.E.; Kirsten, F.; Levi, M.; Siegrist, J. (Lawrence Berkeley Lab., CA (United States)); Amako, K.; Inaba, O.; Kondo, T. (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)); Baden, A.R.; Fong, D.; Hadley, N.; Kunori, S.; Skuja, A. (Maryland U

    1990-01-01

    The NA34 (HELIOS) calorimeter has measured e/{pi} {congruent} 1.1 in a uranium/liquid argon calorimeter with a shaping time of 135 nsec. Lead may be a viable alternative, but e/{pi} must first be measured at fast shaping times in lead. We re preparing to measure e/{pi} at momenta ranging from 0.5 to 20 GeV/c and with shaping times of 50, 100 and 150 nsec.

  11. A measurement of E/{pi} for a fast lead liquid argon calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Makowiecki, D.; Gordon, H.A.; Ma, H.; Murtagh, M.; Radeka, V.; Rahm, D.; Rescia, S. [Brookhaven National Lab., Upton, NY (United States); Abrams, G.S.; Groom, D.E.; Kirsten, F.; Levi, M.; Siegrist, J. [Lawrence Berkeley Lab., CA (United States); Amako, K.; Inaba, O.; Kondo, T. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan); Baden, A.R.; Fong, D.; Hadley, N.; Kunori, S.; Skuja, A. [Maryland Univ., College Park, MD (United States); Bowen, T.; Forden, G.; Jenkins, E.; Johns, K.; Rutherfoord, J.; Shupe, M. [Arizona Univ., Tucson, AZ (United States); Burnett, T.; Cook, V.; Davisson, R.; Mockett, P.; Rothberg, J.; Williams, R.W. [Washington Univ., Seattle, WA (United States); Cremaldi, L.; Reidy, J.; Summers, D. [Mississippi Univ., University, MS (United States); DiGiacomo, N. [Martin Marietta Aerospace, Denver, CO (United States). Astronautics Group; Draper, P.; Ferbel, T.; Lobkowicz, F. [Rochester Univ., NY (United States); Faust, J.; Hauptman, J.; Pang, M. [Iowa State Univ. of Science and Technology, Ames, IA (United States); Gabriel, T.A. [Oak Ridge National Lab., TN (United States); Hagopian, V.; Womersley, J. [Florida State Univ., Tallahassee, FL (United States); Handler, T. [Tennessee Univ., Knoxville, TN (United States); Hitlin, D. [California Inst. of Tech., Pasadena, CA (United States); Mulholland, G.T. [Fermi National Accelerator Lab., Batavia, IL (United States); Watanabe, Y. [Tokyo Inst. of Tech. (Japan); Weerts, H. [Michigan State Univ., East Lansing, MI (United States)

    1990-12-31

    The NA34 (HELIOS) calorimeter has measured e/{pi} {congruent} 1.1 in a uranium/liquid argon calorimeter with a shaping time of 135 nsec. Lead may be a viable alternative, but e/{pi} must first be measured at fast shaping times in lead. We re preparing to measure e/{pi} at momenta ranging from 0.5 to 20 GeV/c and with shaping times of 50, 100 and 150 nsec.

  12. The analog processing system for the Liquid Argon Calorimeter for SLD at SLAC

    International Nuclear Information System (INIS)

    The analog processing system for the Liquid Argon Calorimeter for the SLD project at SLAC is described. Amplification, storage of the analog information, and multiplexing is realized on specially developed hybrids, which will be mounted directly on the detector. This leads to a substantial reduction of the cable plant. Test results for the amplifier and for the sampling and multiplexing hybrid (CDU hybrid) are presented. The latter hybird contains a custom monolithic device, the Calorimeter Data Unit

  13. Development of a Photon Detection System in Liquid Argon for the Long-Baseline Neutrino Experiment

    Science.gov (United States)

    Whittington, Denver; Adams, Brice; Baptista, Brian; Baugh, Brian; Gebhard, Mark; Lang, Michael; Mufson, Stuart; Musser, James; Smith, Paul; Urheim, Jon

    2014-03-01

    The Long-Baseline Neutrino Experiment (LBNE) will be a premier facility for exploring long-standing questions about the boundaries of the standard model. Acting in concert with the liquid argon time projection chambers underpinning the far detector design, the LBNE photon detection system will capture ultraviolet scintillation light in order to provide valuable timing information for event reconstruction. The team at Indiana University is exploring a design based on acrylic waveguides coated with a wavelength-shifting compound, combined with silicon photomultipliers, to collect and record scintillation light from liquid argon. Large-scale tests of this design are being conducted at the ``TallBo'' liquid argon dewar facility at Fermilab, where performance studies with cosmic ray events are helping steer decisions for the final detector design. We present an overview of the design and function of this photon detection system and the latest results from the analysis of data collected during these tests. Photon Detector R&D Team at Indiana University.

  14. Thermal conductivity of liquid argon in nanochannels from molecular dynamics simulations.

    Science.gov (United States)

    Hyżorek, Krzysztof; Tretiakov, Konstantin V

    2016-05-21

    The thermal conductivity of liquid argon in nanochannels has been calculated over a wide range of densities using two independent methods-the Green-Kubo approach in equilibrium molecular dynamics simulations and the Müller-Plathe method in non-equilibrium molecular dynamics simulations. The Lennard-Jones potential was used to model interatomic interactions. The influence of transversal size and shape of a nanochannel on the thermal conductivity of liquid argon along the length of the channel has been investigated. The transversal size of nanochannel varied from 2.25 nm to 15 nm. The simulations revealed that the thermal conductivity weakly depends on the shape (square vs circular) of channel and scales with a cross-sectional area of nanochannel. It has been observed that thermal conductivity increases with an increase of the transversal size of the channel. Also, it reaches bulk values for some characteristic size of channel that depends strongly on density. Good agreement of the computed thermal conductivities of liquid argon over a wide density range with the experimental data allowed the value of the characteristic size of channel as a function of density to be estimated. This value depends on density and varies from 5 nm to 11 nm. PMID:27208958

  15. Photoelectron yield in the prototype of the liquid argon detector for CDEX-10

    CERN Document Server

    Chen, Qing-Hao; Cheng, Jian-Ping; Kang, Ke-Jun; Li, Yuan-Jing; Lin, Shin-Ted; Tang, Chang-Jian; Xing, Hao-Yang; Yu, Xun-Zhen; Zeng, Ming

    2015-01-01

    The China Dark Matter Experiment (CDEX) is a low background experiment at China Jinping Underground Laboratory (CJPL) designed to directly detect dark matter with a high-purity germanium (HPGe) detector. In the second phase CDEX-10 with 10 kg germanium array detector system, the liquid argon (LAr) anti-Compton active shielding and cooling system is proposed. For purpose of studying the properties of LAr detector, a prototype with an active volume of 7 liters of liquid argon was built and operated. The photoelectron yields, as a critically important parameter for the LAr detector, have been measured to be 0.051-0.079 p.e./keV for 662 keV gamma lines at different positions. The good agreement between the experimental and simulation results has provided a quite reasonable understanding and determination of the important parameters such as the Surviving Fraction of the $Ar_{2}^{*}$ excimers, the absorption length for 128 nm photons in liquid argon, the reflectivity of Teflon and so on.

  16. The Development of a 2000L Liquid Argon Time Projection Chamber and its Application to the Search for Proton Decay

    Science.gov (United States)

    Zhou, Ming

    A new type of particle detector, the liquid argon time projection chamber, is developed and systematically tested using cosmic ray muons with a three ton prototype. The main technical problems, such as the liquid argon purity, wire chamber configuration, low noise electronics, and their long term stability, are solved after two years of run. Most of the basic parameters associated with the liquid argon TPC technology, the charge drift velocity, the spatial resolution, charge recombination and diffusion, are extracted. In order to apply this technique to solar neutrino physics, a measurement of the intrinsive radioactive Ar^{42} was performed and the results are compatible with current limits. An application to the search for proton decay with the liquid argon TPC technique is studied and some preliminary results are reported.

  17. Induced luminescence by charged particles on gaseous, liquid and solid argon

    International Nuclear Information System (INIS)

    A spectral and a kinetic study of the scintillation induced by β and α particles in gaseous, liquid and solid argon have been made in the wavelength region comprised between 1100 and 3000A. The radiative lifetimes and some spectroscopic parameters of the lowest dimer states (1Σ+sub(u) and 3Σ+sub(u)) have been determined: tau0(1Σ+sub(u)) = 4.2ns; tau0(3Σ+sub(u)) = 3.1μs; ΔE(1Σ+sub(u)-3Σ+sub(u)) = 52 meV; hω = 230 cm-1. A non radiative de-excitation rate of the 3Σ+sub(u) state has been measured: approximately 2x10-17cm3s-1. By applying an electric field the contribution of the electron-ion recombination mechanism to the gaseous argon scintillation is studied. For condensed argon, the dependence of the ratio between the fluorescence and the phosphorescence intensities on the ionisation power of the impinging particle is verified. The continuum which extends from 1600 to 2900A and that is present only in the gas phase spectra, is ascribed to the radiative de-excitation of molecular ions. A time resolved study of the luminescence of high pressure (1-15atm) argon excited by a pulsed electric discharge has also been performed and is compared with that of the scintillation induced by nuclear particles

  18. A cryogenic monitor system for the Liquid Argon Calorimeter in the SLD detector

    Energy Technology Data Exchange (ETDEWEB)

    Fox, M.J.; Fox, J.D.

    1988-10-01

    This paper describes the monitoring electronics system design for the Liquid Argon Calorimeter (LAC) portion of the SLD detector. This system measures temperatures and liquid levels inside the LAC cryostat and transfers the results over a fiber-optic serial link to an external monitoring computer. System requirements, unique design constraints, and detailed analog, digital and software designs are presented. Fault tolerance and the requirement for a single design to work in several different operating environments are discussed. 4 refs., 3 figs., 1 tab.

  19. A cryogenic monitor system for the Liquid Argon Calorimeter in the SLD detector

    International Nuclear Information System (INIS)

    This paper describes the monitoring electronics system design for the Liquid Argon Calorimeter (LAC) portion of the SLD detector. This system measures temperatures and liquid levels inside the LAC cryostat and transfers the results over a fiber-optic serial link to an external monitoring computer. System requirements, unique design constraints, and detailed analog, digital and software designs are presented. Fault tolerance and the requirement for a single design to work in several different operating environments are discussed. 4 refs., 3 figs., 1 tab

  20. A G/NARRLI Effort. Measuring the Ionization Yield of Low-Energy Nuclear Recoils in Liquid Argon

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Tenzing Henry Yatish [Univ. of California, Berkeley, CA (United States)

    2014-01-01

    Liquid argon has long been used for particle detection due to its attractive drift properties, ample abundance, and reasonable density. The response of liquid argon to lowenergy O(102 -1044 eV) interactions is, however, largely unexplored. Weakly interacting massive particles such as neutrinos and hypothetical dark-matter particles (WIMPs) are predicted to coherently scatter on atomic nuclei, leaving only an isolated low-energy nuclear recoil as evidence. The response of liquid argon to low-energy nuclear recoils must be studied to determine the sensitivity of liquid argon based detectors to these unobserved interactions. Detectors sensitive to coherent neutrino-nucleus scattering may be used to monitor nuclear reactors from a distance, to detect neutrinos from supernova, and to test the predicted behavior of neutrinos. Additionally, direct detection of hypothetical weakly interacting dark matter would be a large step toward understanding the substance that accounts for nearly 27% of the universe. In this dissertation I discuss a small dual-phase (liquid-gas) argon proportional scintillation counter built to study the low-energy regime and several novel calibration and characterization techniques developed to study the response of liquid argon to low-energy O(102 -104 eV) interactions.

  1. The ICARUS T600 Liquid Argon Detector Operation in the Underground Gran Sasso Laboratory

    CERN Document Server

    Vignoli, C

    2014-01-01

    The ICARUS T600 Module is the largest liquid argon detector (760 t LAr mass) ever realized to study neutrino oscill ations and matter stability in the deep underground Gran Sasso Laboratory. One of t he key elements for the detector performance is the liquid argon purity: residual electronegative compounds in argon have to be kept as low as 0.1 part s per billion all over the detector run. The T600 Module design was finalized by the ICARUS Collaboration after years of R&D studies that brought to the viable and scalable industrial solutions necessary for sized experiments with severe safety prescriptions for the underground operation . We present the T600 Module successful commissioning and the 3-years efficient, stable and continuous operation with extraordinary LAr purity, high performance and zero dead time data taking . This result demonstrates for the first time the feasibility of activation and long-term run in safe conditions of sized cryogenic detectors even in a confined underground location and r...

  2. Liquid Argon Time Projection Chamber research and development in the United States

    International Nuclear Information System (INIS)

    A workshop was held at Fermilab on March 20-21, 2013 to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in seven topical plenary sessions: i) Argon Purity, ii) Cryogenics, iii) TPC and High Voltage, iv) Electronics, Data Acquisition and Triggering, v) Scintillation Light Detection, vi) Calibration and Test Beams, and vii) Software. This document summarizes the current efforts in each of these areas. It also highlights areas in LArTPC research and development that are common between neutrino experiments and dark matter experiments

  3. Liquid Argon Time Projection Chamber research and development in the United States

    Science.gov (United States)

    Baller, B.; Bromberg, C.; Buchanan, N.; Cavanna, F.; Chen, H.; Church, E.; Gehman, V.; Greenlee, H.; Guardincerri, E.; Jones, B.; Junk, T.; Katori, T.; Kirby, M.; Lang, K.; Loer, B.; Marchionni, A.; Maruyama, T.; Mauger, C.; Menegolli, A.; Montanari, D.; Mufson, S.; Norris, B.; Pordes, S.; Raaf, J.; Rebel, B.; Sanders, R.; Soderberg, M.; St. John, J.; Strauss, T.; Szelc, A.; Tope, T.; Touramanis, C.; Thorn, C.; Urheim, J.; Van de Water, R.; Wang, H.; Yu, B.; Zuckerbrot, M.

    2014-05-01

    A workshop was held at Fermilab on March 20-21, 2013 to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in seven topical plenary sessions: i) Argon Purity, ii) Cryogenics, iii) TPC and High Voltage, iv) Electronics, Data Acquisition and Triggering, v) Scintillation Light Detection, vi) Calibration and Test Beams, and vii) Software. This document summarizes the current efforts in each of these areas. It also highlights areas in LArTPC research and development that are common between neutrino experiments and dark matter experiments.

  4. Tetraphenyl-butadiene films: VUV-Vis optical characterization from room to liquid argon temperature

    Science.gov (United States)

    Francini, R.; Montereali, R. M.; Nichelatti, E.; Vincenti, M. A.; Canci, N.; Segreto, E.; Cavanna, F.; Di Pompeo, F.; Carbonara, F.; Fiorillo, G.; Perfetto, F.

    2013-09-01

    A thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor's optical window is the most common solution to down convert argon VUV scintillation light in current and planned liquid argon based experiments for dark matter searches and neutrino physics. Characterization of the main features of TPB coatings on different, commonly used substrates is reported, as a result of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission.

  5. Liquid Argon Time Projection Chamber Research and Development in the United States

    CERN Document Server

    Bromberg, C; Junk, T; Katori, T; Lang, K; Marchionni, A; Mauger, C; Mufson, S; Pordes, S; Raaf, J; Rebel, B; Soderberg, M; Thorn, C; Urheim, J

    2013-01-01

    A workshop was held at Fermilab on March 20-21, 2013 to discuss the development of liquid argon time projection chambers (LArTPC) in the United States. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in plenary sessions organized into seven topical categories: $i)$ Argon Purity, $ii)$ Cryogenics, $iii)$ TPC and High Voltage, $iv)$ Electronics, Data Acquisition and Triggering, $v)$ Scintillation Light Detection, $vi)$ Calibration and Test Beams, and $vii)$ Software. This document summarizes the current efforts in each of these topical categories. It also highlights areas in LArTPC research and development that are common between neutrino experiments and dark matter experiments.

  6. Cryogenic Gaseous Photomultiplier for Position Reconstruction of Liquid Argon Scintillation Light

    CERN Document Server

    Paredes, B Lopez; Paganis, S; Silva, A L M; Spooner, N J C; Veloso, J F C A

    2015-01-01

    Presented here are first tests of a Gaseous Photomultiplier based on a cascade of Thick GEM structures intended for gamma-ray position reconstruction in liquid Argon. The detector has a MgF$_2$ window, transparent to VUV light, and a CsI photocathode deposited on the first THGEM. A gain of $8\\cdot10^{5}$ per photoelectron and $\\sim100\\%$ photoelectron collection efficiency are measured at stable operation settings. The excellent position resolution capabilities of the detector (better than 100 $\\mu$m) at 100 kHz readout rate, is demonstrated at room temperature. Structural integrity tests of the detector and seals are successfully performed at cryogenic temperatures by immersing the detector in liquid Nitrogen, laying a good foundation for future operation tests in noble liquids.

  7. Fluctuation in energy-loss measurements in allene-doped liquid argon for heavy ions

    International Nuclear Information System (INIS)

    Liquid argon (LAr) has suitable properties for use as a particle-detector medium, however, its response to heavy ions is not linear, because of the non-perfect collection of charge produced by the incident ions due to the strong recombination between the liberated electrons and argon ions. We were able to improve the linearity of the response by doping photoionization materials, such as allene (C3H4), to LAr. Using allene-doped LAr, we made some experiments of the heavy ion calorimeters for the mass identification of relativistic iron ions, but this approach was unsuccessful. We therefore investigated the cause of the failure using relativistic heavy ions of neon, argon and iron. The energy resolutions obtained experimentally were of the order of several percent at the full width at half maximum (FWHM) for neon to iron ions passing through a LAr gap of 10 mm. These values were 2 or 3 times worse than those predicted theoretically, and the poor energy resolution led to insufficient mass resolution. Here, we describe methods for measuring fluctuation in energy-loss signals in LAr, and discuss the factors determining the resolution

  8. A liquid argon time projection chamber for the solar neutrino problem

    International Nuclear Information System (INIS)

    The construction and successful test of a large liquid argon time projection chamber prototype detector is presented. This effort is a part of the ICARUS project which is aimed at the development of new detector techniques to uncover the very rare events like proton decay and solar neutrinos. The construction and test of this detector has been carried out at CERN from 1989 until the present time. The charge lifetime measured is 3.19 ± 0.13 ms. The authors also report on a precision measurement of lifetime by a laser monitoring chamber and the operation of the recirculation system essential to keeping liquid for a long time. They show that a liquid argon detector is very well suited to study mass-enhanced neutrino oscillation (MSW effect) from the Sun by detecting simultaneous two modes of reaction. Ratio of two modes provides a model independent probe of neutrino oscillation, free of deviations from different solar models. Contours plots are presented at various threshold energies

  9. a Liquid Argon Time Projection Chamber for the Solar Neutrino Problem

    Science.gov (United States)

    Cheng, Mao-Tung

    The construction and successful test of a large liquid argon time projection chamber prototype detector is presented. This effort is a part of the ICARUS project which is aimed at the development of new detector techniques to uncover the very rare events like proton decay and solar neutrinos. The construction and test of this detector has been carried out at CERN from 1989 until the present time. The charge lifetime measured is 3.19 +/- 0.13 ms. We also report on a precision measurement of lifetime by a laser monitoring chamber and the operation of the recirculation system essential to keeping liquid for a long time. We show that a liquid argon detector is very well suited to study mass-enhanced neutrino oscillation (MSW effect) from the Sun by detecting simultaneous two modes of reaction. Ratio of two modes provides a model independent probe of neutrino oscillation, free of deviations from different solar models. Contour plots are presented at various threshold energies.

  10. WA105: a large-scale demonstrator of the Liquid Argon double phase TPC

    Science.gov (United States)

    Tonazzo, A.; WA105 Collaboration

    2016-05-01

    The physics case for a large underground detector devoted to neutrino oscillation measurements, nucleon decay and astrophysics is compelling. A time projection chamber based on the dual-phase liquid Argon technique is an extremely attractive option, allowing for long drift distances, low energy threshold and high readout granularity. It has been extensively studied in the LAGUNA-LBNO Design Study and is one of the two designs foreseen for the modules of the DUNE detector in the US. The WA105 experiment envisages the construction of a large scale prototype at CERN, to validate technical solutions and perform physics studies with charged particle beams.

  11. A CMOS current preamplifier and shaper with 50Ω line driver for liquid argon preshower

    International Nuclear Information System (INIS)

    In the field of liquid argon calorimetry for the LHC detector program, a CMOS ''current conveyor'' preamplifier was cold preshower. It is an improved version of the ICON circuit which had been formerly designed by the RD2 collaboration. This paper also presents a CMOS linear output buffer, featuring a dynamic range close to ±2V on a 50Ω load, for a 21 mW power dissipation at 77K. Furthermore a biquadratic 7 MHz bandpass filter was developed, based on a high speed rail to rail CMOS operational amplifier. It is meant to be the filter placed at the output of the ICON preamplifier

  12. Optical readout tracking detector concept using secondary scintillation from liquid argon generated by a thick gas electron multiplier

    OpenAIRE

    Lightfoot, P. K.; Barker, G. J.; Mavrokoridis, K.; Ramachers, Y. A.; Spooner, N. J. C.

    2008-01-01

    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...

  13. A multi-term solution of the space-time Boltzmann equation for electrons in gaseous and liquid Argon

    CERN Document Server

    Boyle, G J; Tattersall, W J; McEachran, R P; White, R D

    2015-01-01

    In a recent paper [1] the scattering and transport of excess electrons in liquid argon in the hydrodynamic regime was investigated, generalizing the seminal works of Lekner and Cohen [2,3] with modern scattering theory techniques and kinetic theory. In this paper, the discussion is extended to the non-hydrodynamic regime through the development of a full multi-term space-time solution of Boltzmann's equation for electron transport in gases and liquids using a novel operator-splitting method. A Green's function formalism is considered that enables flexible adaptation to various experimental systems. The spatio-temporal evolution of electrons in liquids in the hydrodynamic regime is studied for a benchmark model Percus-Yevick liquid as well as for liquid argon. The temporal evolution of Franck-Hertz oscillations are observed for liquids, with striking differences in the spatio-temporal development of the velocity distribution function components between the uncorrelated gas and true liquid approximations in arg...

  14. Characterization of decamethylferrocene and ferrocene in ionic liquids: argon and vacuum effect on their electrochemical properties

    International Nuclear Information System (INIS)

    The electrochemistry of decamethylferrocene (DmFc) has been studied in organic solvent systems and proven to be a superior internal reference redox standard to ferrocene (Fc). However, the electrochemical information on this redox couple in ionic liquids is still limited. Therefore, the voltammetric and amperometric behaviour of DmFc was investigated under argon and vacuum conditions in six different ionic liquids and compared to that of Fc under the same experimental conditions. Consequently, the concentration, the heterogeneous electron-transfer rate constant (k0), volatility, and diffusion coefficients (D) of Fc and Fc+, as well as the solubility, k0, and D values for DmFc and DmFc+ were determined under argon and vacuum conditions by fitting the experimental chronoamperometric and voltammetric data with numerical and digital simulations. The rate of mass transport of ferrocene and decamethylferrocene was observed to decreases between 6–37% by changing the working atmosphere from argon to vacuum. The DFc/DFc+ ratios are in the range 1.31-2.01 in the different ILs. Importantly, the DDmFc/DDmFc+ ratio is ≈ 1 in 1-methyl-3-butylimidazolium bis(trifluoromethylsulfonyl)amide, 1-methyl-1-butylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, and 1-methyl-3-ethylimidazolium tris(pentafluoroethyl)trifluorophosphate. The experimental mid-point potential and half-wave potential of Fc0/+ vs. DmFc0/+, as well as the formal potential obtained after correction for inequality in the respective diffusion coefficients of both redox processes are presented. Even though DmFc is not freely soluble in the different ILs, the results presented in this work suggest that the DmFc0/+ redox process is less dependent than Fc on the IL nature. This is a very relevant finding for the application of this transition-metal sandwich complex as an internal reference redox system in IL solutions

  15. ATLAS

    CERN Multimedia

    IT-UDS-Audiovisual Services

    2002-01-01

    The film shows the re-assembly of the liquid Argon endcap cryostat. It has been taken apart in order to repair some stoppers. After this repair, the cold vessel was surrounded with super isolation and was lifted and inserted into the warm vessel. This was a rather delicate operation that was successfully finished!

  16. Radon backgrounds in the DEAP-1 liquid-argon-based Dark Matter detector

    Science.gov (United States)

    Amaudruz, P.-A.; Batygov, M.; Beltran, B.; Boudjemline, K.; Boulay, M. G.; Cai, B.; Caldwell, T.; Chen, M.; Chouinard, R.; Cleveland, B. T.; Contreras, D.; Dering, K.; Duncan, F.; Ford, R.; Gagnon, R.; Giuliani, F.; Gold, M.; Golovko, V. V.; Gorel, P.; Graham, K.; Grant, D. R.; Hakobyan, R.; Hallin, A. L.; Harvey, P.; Hearns, C.; Jillings, C. J.; Kuźniak, M.; Lawson, I.; Li, O.; Lidgard, J.; Liimatainen, P.; Lippincott, W. H.; Mathew, R.; McDonald, A. B.; McElroy, T.; McFarlane, K.; McKinsey, D.; Muir, A.; Nantais, C.; Nicolics, K.; Nikkel, J.; Noble, T.; O'Dwyer, E.; Olsen, K. S.; Ouellet, C.; Pasuthip, P.; Pollmann, T.; Rau, W.; Retiere, F.; Ronquest, M.; Skensved, P.; Sonley, T.; Tang, J.; Vázquez-Jáuregui, E.; Veloce, L.; Ward, M.

    2015-03-01

    The DEAP-1 7 kg single phase liquid argon scintillation detector was operated underground at SNOLAB in order to test the techniques and measure the backgrounds inherent to single phase detection, in support of the DEAP-3600 Dark Matter detector. Backgrounds in DEAP are controlled through material selection, construction techniques, pulse shape discrimination, and event reconstruction. This report details the analysis of background events observed in three iterations of the DEAP-1 detector, and the measures taken to reduce them. The 222 Rn decay rate in the liquid argon was measured to be between 16 and 26 μBq kg-1. We found that the background spectrum near the region of interest for Dark Matter detection in the DEAP-1 detector can be described considering events from three sources: radon daughters decaying on the surface of the active volume, the expected rate of electromagnetic events misidentified as nuclear recoils due to inefficiencies in the pulse shape discrimination, and leakage of events from outside the fiducial volume due to imperfect position reconstruction. These backgrounds statistically account for all observed events, and they will be strongly reduced in the DEAP-3600 detector due to its higher light yield and simpler geometry.

  17. Pulse shape analysis of enriched BEGe detectors in vacuum cryostat and liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Victoria [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    The Gerda experiment searches for the lepton number violating neutrinoless double beta (0νββ) decay of {sup 76}Ge. Germanium diodes of BEGe type (Canberra, Belgium) made from isotopically modified material have been procured for Phase II of Gerda. They will improve the sensitivity of the experiment by additional target mass, improved energy resolution and enhanced pulse shape discrimination (PSD) against background events. The PSD efficiencies of the new enriched BEGe detectors were studied in vacuum cryostats as part of the characterization campaign at the HADES underground laboratory. For a deeper understanding of the pulse shape performance of the enriched BEGe detectors, detailed {sup 241}Am surface scans were performed. Unexpectedly high position-dependence of the pulse shape parameter Amplitude-over-Energy was found for some of the detectors. With further investigation this effect was traced to surface charge effects specific to the operational configuration of the detectors inside the vacuum cryostats. The standard behavior is restored when they are operated in liquid argon in the configuration intended for Gerda Phase II. Finally, five of the enriched BEGe diodes were installed in the Gerda liquid argon cryostat prior to the full upgrade. They show a good performance and are able to reject efficiently multi-site-events as well as β- and α-particles.

  18. Sampling calorimeter for high energy heavy particles filled with allene-doped liquid argon

    International Nuclear Information System (INIS)

    A hadron calorimeter for investigating relativistic heavy ion reactions, filled with liquid argon doped with allene, has been tested for 1 GeV/n neon and iron ions, and 1.7 GeV/n helium, neon and iron ions. The electrode system of the calorimeter consists of G-10 plates placed in the first, second and third parts, 2 mm thick iron plates in the second part and 6 mm thick iron plates in the third part with a liquid argon gap of 3.5 mm. Some of the ions were stopped inside the calorimeter without fragmentation, which were treated separately. The calorimeter shows a good linear response to the total incident energy of ions for fragmented and stopped ions. The absolute yields of collected charge are consistent with the calculated values. An energy resolution in FWHM of 2-.5% is obtained for stopped ions. For fragmented ions, the energy resolution in FWHM is given by [0.9+81.1/√E(GeV)]% for all relativistic ions and if the datum of helium ions is excluded, the resolution can be expressed by [4.8+53.2/√E(GeV)]%. The present energy resolution is better than those recently obtained with scintillation calorimeters at BNL and CERN. (orig.)

  19. Performance of VUV-sensitive MPPC for Liquid Argon Scintillation Light

    CERN Document Server

    Igarashi, T; Tanaka, M; Washimi, T; Yorita, K

    2015-01-01

    A new type of the Multi-Pixel Photon Counter (MPPC), sensitive to Vacuum Ultra-Violet (VUV) light (wavelength {\\lambda} < 150 nm), is recently developed and produced by Hamamatsu Photonics K.K. The basic properties of the new MPPC are measured at cryogenic facility of Waseda university using liquid nitrogen. Temperature dependence of breakdown voltage, capacitance, and dark count rate of the MPPC are also evaluated. In addition, the absolute photon detection efficiency (PDE) for liquid argon (LAr) scintillation light ({\\lambda} = 128 nm) is estimated to be about 7% with uncertainty of 2% by using 241 Am {\\alpha}-ray source. Based on these basic measurements a possible application of the new MPPC to LAr detector for dark matter search is discussed.

  20. Electron recombination in low-energy nuclear recoils tracks in liquid argon

    International Nuclear Information System (INIS)

    This paper presents an analysis of electron-ion recombination processes in ionization tracks of recoiled atoms in liquid argon (LAr) detectors. The analysis is based on the results of computer simulations which use realistic models of electron transport and reactions. The calculations reproduce the recent experimental results of the ionization yield from 6.7 keV nuclear recoils in LAr. The statistical distribution of the number of electrons that escape recombination is found to deviate from the binomial distribution, and estimates of recombination fluctuations for nuclear recoils tracks are obtained. A study of the recombination kinetics shows that a significant part of electrons undergo very fast static recombination, an effect that may be responsible for the weak drift-field dependence of the ionization yield from nuclear recoils in some noble liquids. The obtained results can be useful in the search for hypothetical dark matter particles and in other studies that involve detection of recoiled nuclei

  1. ArgonCube: a novel, fully-modular approach for the realization of large-mass liquid argon TPC neutrino detectors

    CERN Document Server

    Amsler, C; Asaadi, J; Auger, M; Barbato, F; Bay, F; Bishai, M; Bleiner, D; Borgschulte, A; Bremer, J; Cavus, E; Chen, H; De Geronimo, G; Ereditato, A; Fleming, B; Goldi, D; Hanni, R; Kose, U; Kreslo, I; La Mattina, F; Lanni, F; Lissauer, D; Luthi, M; Lutz, P; Marchionni, A; Mladenov, D; Nessi, M; Noto, F; Palamara, O; Raaf, J L; Radeka, V; Rudolph Von Rohr, Ch; Smargianaki, D; Soderberg, M; Strauss, Th; Weber, M; Yu, B; Zeller, G P; Zeyrek, M; CERN. Geneva. SPS and PS Experiments Committee; SPSC

    2015-01-01

    The Liquid Argon Time Projection Chamber is a prime candidate detector for future neutrino oscillation physics experiments, underground neutrino observatories and proton decay searches. A large international project based on this technology is currently being considered at the future LBNF facility in the United States on the very large mass scale of 40 kton. In this document, following the long standing R&D work conducted over the last years in several laboratories in Europe and in the United States, we intend to propose a novel Liquid Argon TPC approach based on a fully-modular, innovative design, the ArgonCube. The related R&D work will proceed along two main directions; one aimed at on the assessment of the proposed modular detector design, the other on the exploitation of new signal readout methods. Such a strategy will provide high performance while being cost-effective and robust at the same time. According to our plans, we will firstly realize a detector prototype hosted in a cryostat that is a...

  2. Development of an anti-Compton veto for HPGe detectors operated in liquid argon using Silicon Photo-Multipliers

    CERN Document Server

    Janicskó-Csáthy, József; Liu, Xiang; Majorovits, Béla; Caldwell, Allen

    2010-01-01

    A proof of concept detector is presented for scintillation light detection in liquid argon using Silicon Photo-Multipliers. The aim of the work is to build an anti-Compton veto for germanium detectors operated directly in liquid argon like in the GERDA experiment. Properties of the Multi-Pixel Photon Counter (MPPC) are studied at cryogenic temperatures. To increase the light collection efficiency of the MPPCs wavelength shifting fibers were used. A veto efficiency comparable to a similar setup with a Photo-Multiplier Tube was achieved.

  3. Development of an anti-compton veto for HPGe detectors operated in liquid argon using silicon photo-multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Janicsko Csathy, Jozsef [Max Planck Institute fuer Physik, Munchen (Germany); Technische Universitat Munchen, Garching (Germany). Fakultaet fuer Physik; Aghaei Khozani, Hossein; Caldwell, Allen; Majorovits, Bela [Max Planck Institute fuer Physik, Munchen (Germany); Liu, Xiang [Max Planck Institute fuer Physik, Munchen (Germany); Shanghai Jiaotong University (China); Collaboration: GERDA-Collaboration

    2011-07-01

    A proof of concept detector is presented for scintillation light detection in liquid argon using Silicon Photo-Multipliers. The aim of the work is to build an anti-Compton veto for germanium detectors operated directly in liquid argon like in the GERDA experiment. Properties of the Multi-Pixel Photon Counter (MPPC) are studied at cryogenic temperatures. To increase the light collection efficiency of the MPPCs wavelength shifting fibers were used. A veto efficiency comparable to a similar setup with a Photo-Multiplier Tube was achieved.

  4. Development of an anti-compton veto for HPGe detectors operated in liquid argon using silicon photo-multipliers

    International Nuclear Information System (INIS)

    A proof of concept detector is presented for scintillation light detection in liquid argon using Silicon Photo-Multipliers. The aim of the work is to build an anti-Compton veto for germanium detectors operated directly in liquid argon like in the GERDA experiment. Properties of the Multi-Pixel Photon Counter (MPPC) are studied at cryogenic temperatures. To increase the light collection efficiency of the MPPCs wavelength shifting fibers were used. A veto efficiency comparable to a similar setup with a Photo-Multiplier Tube was achieved.

  5. Development of an anti-Compton veto for HPGe detectors operated in liquid argon using silicon photo-multipliers

    International Nuclear Information System (INIS)

    A proof of concept detector is presented for scintillation light detection in liquid argon using silicon photo-multipliers. The aim of the work is to build an anti-Compton veto for germanium detectors operated directly in liquid argon as in the GERDA experiment. Wavelength shifting fibers are used to collect the scintillation light and to guide it to Multi-Pixel Photon Counters (MPPC). Sufficient light yield was achieved to realize an effective anti-Compton veto. Properties of the MPPC were studied at cryogenic temperatures and are additionally reported.

  6. Development of an anti-Compton veto for HPGe detectors operated in liquid argon using silicon photo-multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Janicsko Csathy, J., E-mail: janicsko@mppmu.mpg.de [Max-Planck-Institut fuer Physik, Foeringer Ring 6, Muenchen 80805 (Germany); Aghaei Khozani, H.; Caldwell, A.; Liu, X.; Majorovits, B. [Max-Planck-Institut fuer Physik, Foeringer Ring 6, Muenchen 80805 (Germany)

    2011-10-21

    A proof of concept detector is presented for scintillation light detection in liquid argon using silicon photo-multipliers. The aim of the work is to build an anti-Compton veto for germanium detectors operated directly in liquid argon as in the GERDA experiment. Wavelength shifting fibers are used to collect the scintillation light and to guide it to Multi-Pixel Photon Counters (MPPC). Sufficient light yield was achieved to realize an effective anti-Compton veto. Properties of the MPPC were studied at cryogenic temperatures and are additionally reported.

  7. A new concept of y-ray telescope. LArGO: Liquid Argon Gamma-ray Observatory

    OpenAIRE

    Caliandro, Giuseppe Andrea; Rossi, Biagio; Longo, Francesco; Fiorillo, Giuliana; Labanti, Claudio; Sanchez, Federico; Lux, Thorsten

    2013-01-01

    LArGO (Liquid Argon Gamma-ray Observatory) consists of a new design for a $\\gamma$-ray telescope, which exploits the idea of using a Liquid Argon Time Projection Chamber (LAr-TPC) as tracker-converter. Particle tracking in LAr-TPC can efficiently starts since the primary photon vertex. Indeed, while in the present space telescopes the incident photon converts in a tungsten foil, which is a passive material, in a LAr-TPC this conversion happens in LAr itself, which is fully active. In this pro...

  8. A liquid argon scintillation veto for GERDA and LArGe

    International Nuclear Information System (INIS)

    Gerda is an experiment to search for the neutrinoless double beta decay of 76Ge. Bare germanium detectors are operated in a cryostat with 65 m3 of liquid argon (LAr). It has been demonstrated in the LArGe test facility, that the detection of argon scintillation light can be used to effectively suppress background events in the germanium, that simultaneously deposit energy in LAr (LAr veto). Suppression factors up to 103 have been achieved for individual sources. Based on these results, Gerda pursues several options for the light instrumentation of LAr, which have to be compatible with the stringent radiopurity requirements of the experiment and should provide a significant suppression of the background in the region of interest around Qββ at 2039 keV. This talk gives an account of the competing design options under investigation in the Gerda collaboration. Our main design options using photomultiplier tubes (PMT) and silicon photomultipliers (SiPM) are discussed. Their expected performance and progress of development is reported. In addition, results of the LArGe test facility are presented, along with the design criteria that follow for light instrumentation in Gerda.

  9. Operating Instructions for the Cryogenics in the Liquid Argon Detector at CIEMAT

    International Nuclear Information System (INIS)

    Ciemat has wide experience in designing and developing gaseous particle detectors. It has taken part in the building of experiments for CERN accelerators, constructing shares of the muon chambers for L3 experiment in LEP and CMS experiment in LHC. Recently, new concepts for particle detectors have been developed, as a natural evolution from the ones built at Ciemat. These new radiation detectors use liquefied noble gases as active media. A testing system for these kind of liquefied argon detectors has been built at Ciemat, and includes a supporting cryogenic system for the liquefaction and maintenance of the liquid argon needed for operating the detector. This document describes the technical features of this cryogenic system. Besides the documentation of the cryogenic system, this technical report can be of help for the management and upgrading of the detector. As well as an introduction, the report includes the following chapters: The second one is a description of the cryogenics and gas systems. The third chapter shows the controlling electronics. The fourth chapter deals with the important topic that is security, its systems and protocols. The fifth describes the cryogenic operations possible in this equipment. The report is completed with diagrams, schemes, pictures and tables for the easier management of the setup. (Author)

  10. Pulse-shape discrimination and energy resolution of a liquid-argon scintillator with xenon doping

    International Nuclear Information System (INIS)

    Liquid-argon scintillation detectors are used in fundamental physics experiments and are being considered for security applications. Previous studies have suggested that the addition of small amounts of xenon dopant improves performance in light or signal yield, energy resolution, and particle discrimination. In this study, we investigate the detector response for xenon dopant concentrations from 9 ± 5 ppm to 1100 ± 500 ppm xenon (by weight) in 6 steps. The 3.14-liter detector uses tetraphenyl butadiene (TPB) wavelength shifter with dual photomultiplier tubes and is operated in single-phase mode. Gamma-ray-interaction signal yield of 4.0 ± 0.1 photoelectrons/keV improved to 5.0 ± 0.1 photoelectrons/keV with dopant. Energy resolution at 662 keV improved from (4.4 ± 0.2)% (σ) to (3.5 ± 0.2)% (σ) with dopant. Pulse-shape discrimination performance degraded greatly at the first addition of dopant, slightly improved with additional additions, then rapidly improved near the end of our dopant range, with performance becoming slightly better than pure argon at the highest tested dopant concentration. Some evidence of reduced neutron scintillation efficiency with increasing dopant concentration was observed. Finally, the waveform shape outside the TPB region is discussed, suggesting that the contribution to the waveform from xenon-produced light is primarily in the last portion of the slow component

  11. A Demonstration of Light Guides for Light Detection in Liquid Argon TPCs

    Science.gov (United States)

    Ignarra, C. M.

    Liquid Argon (LAr) Time Projection Chambers (TPCs) are a developing technology that is becoming a popular choice for neutrino and dark matter experiments due to the low cost of the LAr as a target material and the high signal effciency and background rejection that these detectors can achieve. When excited by a passing charged particle created in a neutrino interaction, argon produces scintillation light at 128 nm. Several types of systems exist for detecting this light. Most involve shifting the wavelength of the light using Tetraphenyl Butadiene (TPB), resulting in visible light which is detected by a PMT.I will discuss our work on a new system under development for light detection in LAr which uses acrylic lightguides. The lightguides are coated with a thin film consisting of TPB embedded in polystyrene. This system could provide a solution to some of the issues associated with scaling existing systems for a larger future LAr detector. Though we are only in the preliminary stages of this R&D, we have shown that the results are already suffcient for triggering.

  12. Pulse-shape discrimination and energy resolution of a liquid-argon scintillator with xenon doping

    Science.gov (United States)

    Wahl, C. G.; Bernard, E. P.; Lippincott, W. H.; Nikkel, J. A.; Shin, Y.; McKinsey, D. N.

    2014-06-01

    Liquid-argon scintillation detectors are used in fundamental physics experiments and are being considered for security applications. Previous studies have suggested that the addition of small amounts of xenon dopant improves performance in light or signal yield, energy resolution, and particle discrimination. In this study, we investigate the detector response for xenon dopant concentrations from 9 ± 5 ppm to 1100 ± 500 ppm xenon (by weight) in 6 steps. The 3.14-liter detector uses tetraphenyl butadiene (TPB) wavelength shifter with dual photomultiplier tubes and is operated in single-phase mode. Gamma-ray-interaction signal yield of 4.0 ± 0.1 photoelectrons/keV improved to 5.0 ± 0.1 photoelectrons/keV with dopant. Energy resolution at 662 keV improved from (4.4 ± 0.2)% (σ) to (3.5 ± 0.2)% (σ) with dopant. Pulse-shape discrimination performance degraded greatly at the first addition of dopant, slightly improved with additional additions, then rapidly improved near the end of our dopant range, with performance becoming slightly better than pure argon at the highest tested dopant concentration. Some evidence of reduced neutron scintillation efficiency with increasing dopant concentration was observed. Finally, the waveform shape outside the TPB region is discussed, suggesting that the contribution to the waveform from xenon-produced light is primarily in the last portion of the slow component.

  13. Simultaneous operation of a test apparatus filled with liquid argon as bubble chamber, calorimeter and scintillation detector

    International Nuclear Information System (INIS)

    Physics motivations for the use of argon as a new bubble chamber liquid are discussed. Results, obtained from a 2.7 1 argon detector in SPS and SC beams at CERN, comprise its track sensitivity to ionizing particles and to a laser beam in the bubble chamber mode, its use as a calorimeter through the collection of free charges in an electric field and the recording of the scintillation light produced by ionizing particles. Various interference phenomena during the simultaneous use of the hybrid properties, as well as purity requirements on the liquid are discussed. Furthermore, nitrogen and argon/nitrogen mixtures were investigated. Applications of our technique for neutrino experiments at TeV accelerators and as vertex detectors are briefly outlined. In-line holography, successfully tested in BEBC, could simplify the optical track recording and improve the resolution in very large detectors. (orig.)

  14. Three-Dimensional Molecular Dynamics Simulation on Heat Propagation in Liquid Argon

    Institute of Scientific and Technical Information of China (English)

    郭英奎; 过增元; 梁新刚

    2001-01-01

    The propagation behaviour of an initial thermal perturbation in liquid argon is simulated by the molecular dynamics method. The 12-6 Lennard-Jones potential and mirror boundary conditions are employed in the 32768particle three-dimensional simulation. Macroscopic characteristics such as the kinetic temperature, pressure and momentum profiles are monitored during the simulation in order to examine the heat propagation behaviour under a timescale comparable with the relaxation time. The results show that the behaviour is still diffusionlike; no features predicted by the Cattaneo-Vernotte model have been found. The wave-like front of the local temperature may be caused by the adiabatic compression and expansion by the pressure wave generated by the thermal expansion.

  15. Liquid argon detector study. Application for 2 end-cap calorimeter in CELLO experiment

    International Nuclear Information System (INIS)

    In the framework of the CELLO experiment designed to study e+e- annihilation at very high energy (2x15 GeV) in the Hamburg collision ring PETRA, the laboratoire de l'Accelerateur Lineaire of Orsay has built 2 end-cap liquid argon calorimeter. The purpose of such a detector is to measure the energy of the e- and of the photons and also to reconstruct their trajectories. Furthermore, it provides an efficient separation between electrons and hadrons. A hadron identification is possible at low momenta by dE/dx measurements. The principle of the detector and associated electronics problems are analyzed in detail. The good behavior of this calorimeter has been tested with 500 MeV electrons at Orsay and with 1 to 10 GeV electrons and hadrons at CERN. Energy resolution goes like 8% /√E and spatial precision is 5 mm. Hadron rejection rate is 2000

  16. Performance of the electronics for the liquid argon calorimeter system of the SLC large detector

    International Nuclear Information System (INIS)

    Results of performance tests on electrons for the Liquid Argon Calorimeter (LAC) for the SLD experiment at SLAC are presented. The behavior of a sub-unit called a ''tophat,'' which processes 720 detector signals, is described. The electronics consists of charge sensitive preamplifiers, analog memories , A/D converters, and associated control and readout circuitry. An internal charge injection system is used to calibrate the overall response of the devices. Linearity is better than 1% for 0-28 pC charge at the input of the amplifiers. Noise (expressed as equivalent input charge) is less than 3,000 electrons at a shaping time of 4 μs, with a slope of 2,600 e/sup -//nF. Crosstalk to adjacent channels is less than 0.5%. The power consumption at a duty cycle of 13% is 61 W

  17. Solar neutrino detection in a large volume double-phase liquid argon experiment

    CERN Document Server

    Franco, D; Agnes, P; Agostino, L; Bottino, B; Davini, S; De Cecco, S; Fan, A; Fiorillo, G; Galbiati, C; Goretti, A M; Hungerford, E V; Ianni, Al; Ianni, An; Jollet, C; Marini, L; Martoff, C J; Meregaglia, A; Pagani, L; Pallavicini, M; Pantic, E; Pocar, A; Renshaw, A L; Rossi, B; Rossi, N; Suvorov, Y; Testera, G; Tonazzo, A; Wang, H; Zavatarelli, S

    2015-01-01

    The direct search for dark matter WIMP particles through their interaction with nuclei at the "neutrino floor" sensitivity, where neutrino-induced coherent scattering on nuclei starts contributing to the background, requires detectors capable of collecting exposures of the order of 1~ktonne yr free of background resulting from beta and gamma decays and cosmogenic and radiogenic neutrons. The same constraints are required for precision measurements of solar neutrinos elastically scattering on electrons. Two-phase liquid argon time projection chambers (LAr TPCs) are prime candidates for the ambitious program to explore the nature of dark matter. The large target, high scintillation light yield and good spatial resolution in all three cartesian directions concurrently allows a high precision measurement of solar neutrino fluxes. We studied the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equival...

  18. Rad-hard electronics development program for SSC liquid-argon calorimeters

    International Nuclear Information System (INIS)

    The development program for radiation-hard low-noise low-power front-end electronics for SSC calorimetry is described. Radiation doses of up to 20 MRad and neutron fluences of 1014 neutrons/cm2 are expected over ten years of operation. These effects are simulated by exposing JFETs to neutrons and ionizing radiation and measuring the resulting bias, leakage current and noise variations. In the case of liquid-argon calorimeters, a large part of the front-end circuitry may be located directly within the low-temperature environment (90 K), placing additional constraints on the choice of components and on the design. This approach minimizes the noise and the response time. The radiation damage test facilities at Argonne will also be described. These include sources of neutrons, electrons, and gamma radiation. 8 refs., 9 figs

  19. GLADE Global Liquid Argon Detector Experiment: a letter of intent to FNAL

    International Nuclear Information System (INIS)

    The recent measurements of the θ13 mixing angle, which controls the observable size of any CP violation effects, open a window of opportunity to take advantage of the world's most powerful existing neutrino beam together with recent successes in development of the ultimate detector technology for the detection of electron neutrinos : a liquid argon (LAr) time projection chamber. During this proposed project a 5kt LAr detector (GLADE) will be developed by European groups to be put in a cryostat in the NuMI neutrino beam at Fermi National Accelerator Laboratory in the US and will start taking data in 3-5 years time to address the neutrino mass ordering. The successful fruition of this project, along with nominal exposure at NOνA and T2K, together with information from double beta decay experiments could ascertain that neutrinos are Dirac particles in the next decade.

  20. ATLAS' major cooling project

    CERN Document Server

    2005-01-01

    In 2005, a considerable effort has been put into commissioning the various units of ATLAS' complex cryogenic system. This is in preparation for the imminent cooling of some of the largest components of the detector in their final underground configuration. The liquid helium and nitrogen ATLAS refrigerators in USA 15. Cryogenics plays a vital role in operating massive detectors such as ATLAS. In many ways the liquefied argon, nitrogen and helium are the life-blood of the detector. ATLAS could not function without cryogens that will be constantly pumped via proximity systems to the superconducting magnets and subdetectors. In recent weeks compressors at the surface and underground refrigerators, dewars, pumps, linkages and all manner of other components related to the cryogenic system have been tested and commissioned. Fifty metres underground The helium and nitrogen refrigerators, installed inside the service cavern, are an important part of the ATLAS cryogenic system. Two independent helium refrigerators ...

  1. Giant Liquid Argon Observatory for Proton Decay, Neutrino Astrophysics and CP-violation in the Lepton Sector (GLACIER)

    CERN Document Server

    Badertscher, A; Degunda, U; Epprecht, L; Horikawa, S; Knecht, L; Lazzaro, C; Lussi, D; Marchionni, A; Natterer, G; Otiougova, P; Resnati, F; Rubbia, A; Strabel, C; Ulbricht, J; Viant, T

    2010-01-01

    GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) is a large underground observatory for proton decay search, neutrino astrophysics and CP-violation studies in the lepton sector. Possible underground sites are studied within the FP7 LAGUNA project (Europe) and along the JPARC neutrino beam in collaboration with KEK (Japan). The concept is scalable to very large masses.

  2. Prime wires for ATLAS

    CERN Multimedia

    2003-01-01

    In an award ceremony on 3 September, ATLAS honoured the French company Axon Cable for its special coaxial cables, which were purpose-built for the Liquid Argon calorimeter modules. Working for CERN since the 1970s, Axon' Cable received the ATLAS supplier award last week for its contribution to the liquid argon calorimeter cables of ATLAS (LAL/Orsay, France and University of Victoria, Canada), started in 1996. Its two sets of minicoaxial cables, called harnesses "A" and "B", are designed to function in the harsh conditions in the liquid argon (at 90 Kelvin or -183°C) and under extreme radiation (up to several Mrads). The cables are mainly used for the readout of the calorimeters, and are connected to the outside world by 114 signal feedthroughs with 1920 channels each. The signal from the detectors is transmitted directly without any amplification, which imposes tight restrictions on the impedance and on the signal propagation time of the cables. Peter Jenni, ATLAS spokesperson, gives the award for best s...

  3. Low-energy (<10keV) electron ionization and recombination model for a liquid argon detector

    International Nuclear Information System (INIS)

    Detailed understanding of the ionization process in noble liquid detectors is important for their use in applications such as the search for dark matter and coherent elastic neutrino-nucleus scattering. The response of noble liquid detectors to low-energy ionization events is poorly understood at this time. We describe a new simulation tool which predicts the ionization yield from electronic energy deposits (E<10keV) in liquid Ar, including the dependence of the yield on the applied electric drift field. The ionization signal produced in a liquid argon detector from 37Ar beta decay and 55Fe X-rays has been calculated using the new model

  4. Atomistic modelling of evaporation and explosive boiling of thin film liquid argon over internally recessed nanostructured surface

    Science.gov (United States)

    Hasan, Mohammad Nasim; Shavik, Sheikh Mohammad; Rabbi, Kazi Fazle; Haque, Mominul

    2016-07-01

    Molecular dynamics (MD) simulations have been carried out to investigate evaporation and explosive boiling phenomena of thin film liquid argon on nanostructured solid surface with emphasis on the effect of solid-liquid interfacial wettability. The nanostructured surface considered herein consists of trapezoidal internal recesses of the solid platinum wall. The wetting conditions of the solid surface were assumed such that it covers both the hydrophilic and hydrophobic conditions and hence effect of interfacial wettability on resulting evaporation and boiling phenomena was the main focus of this study. The initial configuration of the simulation domain comprised of a three phase system (solid platinum, liquid argon and vapor argon) on which equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. After equilibrium of the three-phase system was established, the wall was set to different temperatures (130 K and 250 K for the case of evaporation and explosive boiling respectively) to perform non-equilibrium molecular dynamics (NEMD). The variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat flux normal to the solid surface was also calculated to illustrate the effectiveness of heat transfer for hydrophilic and hydrophobic surfaces in cases of both nanostructured surface and flat surface. The results obtained show that both the wetting condition of the surface and the presence of internal recesses have significant effect on normal evaporation and explosive boiling of the thin liquid film. The heat transfer from solid to liquid in cases of surface with recesses are higher compared to flat surface without recesses. Also the surface with higher wettability (hydrophilic) provides more favorable conditions for boiling than the low-wetting surface (hydrophobic) and therefore, liquid argon responds quickly and shifts from liquid to vapor phase faster in

  5. A Measurement of the Absorption of Liquid Argon Scintillation Light by Dissolved Nitrogen at the Part-Per-Million Level

    CERN Document Server

    Jones, B J P; Conrad, J M; Ignarra, C M; Katori, T; Toups, M

    2013-01-01

    We report on a measurement of the absorption length of scintillation light in liquid argon due to dissolved nitrogen at the part-per-million (ppm) level. We inject controlled quantities of nitrogen into a high purity volume of liquid argon and monitor the light yield from an alpha source. The source is placed at different distances from a cryogenic photomultiplier tube assembly. By comparing the light yield from each position we extract the absorption cross section of nitrogen. We find that nitrogen absorbs argon scintillation light with strength of $\\left(1.51\\pm 0.15\\right)\\times10^{-4} \\;\\mathrm{cm^{-1} ppm^{-1}}$, corresponding to an absorption cross section of $\\left(4.99 \\pm 0.51 \\right)\\times10^{-21}\\;\\mathrm{cm^{2} molecule^{-1}}$. We obtain the relationship between absorption length and nitrogen concentration over the 0 to 50 ppm range and discuss the implications for the design and data analysis of future large liquid argon time projection chamber (LArTPC) detectors. Our results indicate that for a ...

  6. A measurement of the absorption of liquid argon scintillation light by dissolved nitrogen at the part-per-million level

    Science.gov (United States)

    Jones, B. J. P.; Chiu, C. S.; Conrad, J. M.; Ignarra, C. M.; Katori, T.; Toups, M.

    2013-07-01

    We report on a measurement of the absorption length of scintillation light in liquid argon due to dissolved nitrogen at the part-per-million (ppm) level. We inject controlled quantities of nitrogen into a high purity volume of liquid argon and monitor the light yield from an alpha source. The source is placed at different distances from a cryogenic photomultiplier tube assembly. By comparing the light yield from each position we extract the absorption cross section of nitrogen. We find that nitrogen absorbs argon scintillation light with strength of (1.51±0.15) × 10-4 cm-1ppm-1, corresponding to an absorption cross section of (4.99±0.51) × 10-21 cm2molecule-1. We obtain the relationship between absorption length and nitrogen concentration over the 0 to 50 ppm range and discuss the implications for the design and data analysis of future large liquid argon time projection chamber (LArTPC) detectors. Our results indicate that for a current-generation LArTPC, where a concentration of 2 parts per million of nitrogen is expected, the attenuation length due to nitrogen will be 30±3 meters.

  7. MicroBooNE and the Road to Large Liquid Argon Neutrino Detectors

    Science.gov (United States)

    Karagiorgi, G.

    Liquid Argon Time Projection Chambers (LArTPC's) provide a promising technology for multi-kiloton scale detectors aiming to address-among other pressing particle physics questions-the possibility of short and long baseline electron neutrino and antineutrino appearance. MicroBooNE, a 170 ton LArTPC under construction, is the next necessary step in a phased R&D effort toward construction and stable operation of larger-scale LArTPC's. This development effort also leans heavily on the ArgoNeuT and LAr1 LArTPC R&D experiments at Fermilab. In addition to advancing the LArTPC technology, these projects also provide unique physics opportunities. For example, Micro-BooNE will be located in the Booster Neutrino Beamline at Fermilab, at ∼470 m from neutrino production. Thus, in addition to measuring a suite of low energy neutrino cross sections on argon, MicroBooNE will investigate the anomalous low energy excess seen by the MiniBooNE experiment. Furthermore, the neutrino beam energy and relatively short baseline provide MicroBooNE with sensitivity to high-∼m2 neutrino oscillations. These proceedings summarize the role of the MicroBooNE detector in the US LArTPC R&D program, present its physics reach, and briefly discuss the physics potential of a dedicated near-future neutrino oscillation program at the Booster Neutrino Beamline, as a way to maximize the physics output of the Fermilab LArTPC R&D projects.

  8. Solar neutrino detection in a large volume double-phase liquid argon experiment

    Science.gov (United States)

    Franco, D.; Giganti, C.; Agnes, P.; Agostino, L.; Bottino, B.; Canci, N.; Davini, S.; De Cecco, S.; Fan, A.; Fiorillo, G.; Galbiati, C.; Goretti, A. M.; Hungerford, E. V.; Ianni, Al.; Ianni, An.; Jollet, C.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Pagani, L.; Pallavicini, M.; Pantic, E.; Pocar, A.; Razeti, M.; Renshaw, A. L.; Rossi, B.; Rossi, N.; Suvorov, Y.; Testera, G.; Tonazzo, A.; Wang, H.; Zavatarelli, S.

    2016-08-01

    Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne-yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the ``neutrino floor'' (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ~15% precision, and significantly improve the precision of the 7Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.

  9. Operating Instructions for the Cryogenics in the Liquid Argon Detector at CIEMAT; Operacion de la Criogenia del Detector de Argon Liquido del CIEMAT

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L.; Leal, M. D.; Prado, M. del; Ramirez, J. L.

    2009-12-19

    Ciemat has wide experience in designing and developing gaseous particle detectors. It has taken part in the building of experiments for CERN accelerators, constructing shares of the muon chambers for L3 experiment in LEP and CMS experiment in LHC. Recently, new concepts for particle detectors have been developed, as a natural evolution from the ones built at Ciemat. These new radiation detectors use liquefied noble gases as active media. A testing system for these kind of liquefied argon detectors has been built at Ciemat, and includes a supporting cryogenic system for the liquefaction and maintenance of the liquid argon needed for operating the detector. This document describes the technical features of this cryogenic system. Besides the documentation of the cryogenic system, this technical report can be of help for the management and upgrading of the detector. As well as an introduction, the report includes the following chapters: The second one is a description of the cryogenics and gas systems. The third chapter shows the controlling electronics. The fourth chapter deals with the important topic that is security, its systems and protocols. The fifth describes the cryogenic operations possible in this equipment. The report is completed with diagrams, schemes, pictures and tables for the easier management of the setup. (Author)

  10. Investigation of n+ surface events in HPGe detectors for liquid argon background rejection in GERDA

    International Nuclear Information System (INIS)

    The GERDA experiment is searching for neutrinoless double beta decay (0νββ) in 76Ge using an array of germanium detectors immersed in liquid argon (LAr). Phase II of the experiment aims to improve the background level by a factor 10 in order to reach 10-3 counts / (kg.keV.yr). A strong suppression technique is required to suppress the intrinsic LAr background of 42Ar/42K. 30 newly produced p-type Broad Energy Germanium (BEGe) detectors will be deployed in Phase II. The n+ electrode of the GERDA BEGe detectors is covering 96-98 % of the surface and is between 0.5 and 1.2 mm thick. Betas from the 42K decay can penetrated the detector surface and deposit energies within the 0νββ region. Experiences from GERDA Phase I show that these surface events are the dominate background component without suppression. Energy depositions inside the n+ layer create pulse shapes that are slower than those from interactions in the bulk. This talk presents a rejection technique for those events. The signal development inside the n+ layer is modeled and applied in Geant4 Monte Carlo simulations. The simulations are compared with data for 241Am and 90Sr calibration source measurements. The suppression capabilities are extrapolated for 42K in GERDA Phase II.

  11. In-situ measurement of the light attenuation in liquid argon in the GERDA cryostat

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Birgit [IKTP, TU Dresden (Germany); Collaboration: GERDA-Collaboration

    2015-07-01

    GERDA is an experiment searching for neutrinoless double beta decay in {sup 76}Ge. It uses germanium detectors which are enriched in {sup 76}Ge and operates them naked in liquid argon (LAr), which serves both as a coolant and a shield for external radiation. For phase II of GERDA it is planned to reach an exposure of 100 kg . yr with a BI of 10{sup -3} cts/(kg . yr . keV). One of the major improvements to further reduce the BI is to instrument the LAr to act as an additional background veto. The attenuation of the scintillation light in LAr creates a constraint on the effective active volume of the LAr veto and is therefore a key parameter to characterize the instrumentation. In order to measure the light attenuation in LAr, a setup was designed that could be deployed directly into the GERDA cryostat. This setup contains a movable beta source and a PMT to detect the scintillation light at different distances. The talk will describe in detail the construction of the setup, its successful deployment in the GERDA cryostat and the consecutive analysis of the acquired data.

  12. In-situ measurement of the light attenuation in liquid argon in the GERDA cryostat

    International Nuclear Information System (INIS)

    GERDA is an experiment searching for neutrinoless double beta decay in 76Ge. It uses germanium detectors which are enriched in 76Ge and operates them naked in liquid argon (LAr), which serves both as a coolant and a shield for external radiation. For phase II of GERDA it is planned to reach an exposure of 100 kg . yr with a BI of 10-3 cts/(kg . yr . keV). One of the major improvements to further reduce the BI is to instrument the LAr to act as an additional background veto. The attenuation of the scintillation light in LAr creates a constraint on the effective active volume of the LAr veto and is therefore a key parameter to characterize the instrumentation. In order to measure the light attenuation in LAr, a setup was designed that could be deployed directly into the GERDA cryostat. This setup contains a movable beta source and a PMT to detect the scintillation light at different distances. The talk will describe in detail the construction of the setup, its successful deployment in the GERDA cryostat and the consecutive analysis of the acquired data.

  13. Operation of a GERDA Phase I prototype detector in liquid argon and nitrogen

    CERN Document Server

    Heider, M Barnabé; Bezrukov, L; Cattadori, C; Chkvorets, O; Gusev, K; Hult, M; Lebedev, V; Marissens, G; Peiffer, P; Schönert, S; Shirchenko, M; Smolnikov, A; Vasilev, S; Zhukov, S

    2008-01-01

    The GERDA (GERmanium Detector Array) experiment aiming to search for the neutrinoless double beta decay of 76Ge at the Laboratori Nazionali Del Gran Sasso (LNGS), Italy, will operate bare enriched high-purity germanium (HPGe) detectors in liquid argon. GERDA Phase I will use the enriched diodes from the previous Heidelberg-Moscow (HdM) and IGEX experiments. With the HPGe detectors mounted in a low-mass holder, GERDA aims at an excellent energy resolution and extremely low background. The goal is to check the claim for the neutrinoless double beta decay evidence in the HdM 76Ge experiment within one year of data taking. Before dismounting the enriched diodes from their cryostat, the performance parameters of the HdM and the IGEX detectors have been measured. The diodes have been removed from their cryostats, their dimensions measured and they have been put under va-cuum in a transportation container. They are now being refurbished for GERDA Phase I at Canberra Semiconductor NV. Before operating the enriched di...

  14. Rise of an argon bubble in liquid steel in the presence of a transverse magnetic field

    Science.gov (United States)

    Vanka, Surya Pratap; Jin, Kai; Kumar, Purushotam; Thomas, Brian

    2015-11-01

    In this work, the motion of a single argon gas bubble rising in quiescent liquid steel under an external magnetic field is studied numerically using a Volume-of-Fluid (VOF) method. To mitigate spurious velocities normally generated during numerical simulation of multiphase flows with large density differences, an improved algorithm for surface tension modeling, originally proposed by Wang and Tong is implemented, validated and used in present computations. The governing equations are integrated by a second-order space and time accurate numerical scheme, and implemented on multiple Graphics Processing Units (GPU) with high parallel efficiency. The motion and the terminal velocities of the rising bubble under different magnetic fields are compared and a reduction in rise velocity is seen in cases with the magnetic field applied. The shape deformation and the path of the bubble are discussed. An elongation of the bubble along the field direction is seen, and the physics behind these phenomena is discussed. The circulation inside of the bubble is seen to be affected by the magnetic field indirectly. The wake structures behind the bubble are visualized and effects of the magnetic field on the wake structures are presented.

  15. Pulse-shape discrimination and energy resolution of a liquid-argon scintillator with xenon doping

    CERN Document Server

    Wahl, Christopher G; Lippincott, W Hugh; Nikkel, James A; Shin, Yunchang; McKinsey, Daniel N

    2014-01-01

    Liquid-argon scintillation detectors are used in fundamental physics experiments and are being considered for security applications. Previous studies have suggested that the addition of small amounts of xenon dopant improves performance in light or signal yield, energy resolution, and particle discrimination. In this study, we investigate the detector response for xenon dopant concentrations from 9 +/- 5 ppm to 1100 +/- 500 ppm xenon (by weight) in 6 steps. The 3.14-liter detector uses tetraphenyl butadiene (TPB) wavelength shifter with dual photomultiplier tubes and is operated in single-phase mode. Gamma-ray-interaction signal yield of 4.0 +/- 0.1 photoelectrons/keV improved to 5.0 +/- 0.1 photoelectrons/keV with dopant. Energy resolution at 662 keV improved from (4.4 +/- 0.2)% ({\\sigma}) to (3.5 +/- 0.2)% ({\\sigma}) with dopant. Pulse-shape discrimination performance degraded greatly at the first addition of dopant, slightly improved with additional additions, then rapidly improved near the end of our dopa...

  16. Image Processing Techniques applied to Liquid Argon Time Projection Chamber Data

    Science.gov (United States)

    Esquivel, Jessica; MicroBooNE Collaboration

    2015-04-01

    Large scale Liquid Argon Time Projection Chambers(LArTPC), like MicroBooNE, offer new ways to study neutrino cross sections and neutrino oscillations. The data from these LArTPCs are very detailed images of charged particles passing through the detector. A plethora of hit finding, cluster finding and tracking algorithms have been implemented to process data coming from MicroBooNE, but it is still possible that particle tracks that are easily visible by eye are being missed during data processing. Because the human eye sometimes does a better job at finding particle tracks that are sometimes missed by data processing, using Image Processing algorithms which emulate the human eye in conjunction with the already implemented algorithms could be beneficial. In particular Edge Detection algorithms could be useful due to the fact that tracks will often have defined deposited energy along straight lines. This talk will cover preliminary data processed with Edge Detection algorithms, and discussion of what the potential benefits are to this approach to LArTPC data analysis. On behalf of the MicroBooNE Collaboration.

  17. Anode-coupled readout for light collection in Liquid Argon TPCs

    Science.gov (United States)

    Moss, Z.; Toups, M.; Bugel, L.; Collin, G. H.; Conrad, J. M.

    2016-03-01

    This paper will discuss a new method of signal read-out from photon detectors in ultra-large, underground liquid argon time projection chambers. In this design, the signal from the light collection system is coupled via capacitive plates to the TPC wire-planes. This signal is then read out using the same cabling and electronics as the charge information. This greatly benefits light collection: it eliminates the need for an independent readout, substantially reducing cost; it reduces the number of cables in the vapor region of the TPC that can produce impurities; and it cuts down on the number of feed-throughs in the cryostat wall that can cause heat-leaks and potential points of failure. We present experimental results that demonstrate the sensitivity of a LArTPC wire plane to photon detector signals. We also simulate the effect of a 1 μs shaping time and a 2 MHz sampling rate on these signals in the presence of noise, and find that a single photoelectron timing resolution of ~30 ns can be achieved.

  18. Anode-Coupled Readout for Light Collection in Liquid Argon TPCs

    CERN Document Server

    Moss, Z; Bugel, L; Collin, G H; Conrad, J M

    2015-01-01

    This paper will discuss a new method of signal read-out from photon detectors in ultra-large, underground liquid argon time projection chambers. In this design, the signal from the light collection system is coupled via capacitive plates to the TPC wire-planes. This signal is then read out using the same cabling and electronics as the charge information. This greatly benefits light collection: it eliminates the need for an independent readout, substantially reducing cost; It reduces the number of cables in the vapor region of the TPC that can produce impurities; And it cuts down on the number of feed-throughs in the cryostat wall that can cause heat-leaks and potential points of failure. We present experimental results that demonstrate the sensitivity of a LArTPC wire plane to photon detector signals. We also simulate the effect of a 1 $\\mu$s shaping time and a 2 MHz sampling rate on these signals in the presence of noise, and find that a single photoelectron timing resolution of $\\sim$30 ns can be achieved.

  19. A new concept of y-ray telescope. LArGO: Liquid Argon Gamma-ray Observatory

    CERN Document Server

    Caliandro, Giuseppe Andrea; Longo, Francesco; Fiorillo, Giuliana; Labanti, Claudio; Sanchez, Federico; Lux, Thorsten

    2013-01-01

    LArGO (Liquid Argon Gamma-ray Observatory) consists of a new design for a $\\gamma$-ray telescope, which exploits the idea of using a Liquid Argon Time Projection Chamber (LAr-TPC) as tracker-converter. Particle tracking in LAr-TPC can efficiently starts since the primary photon vertex. Indeed, while in the present space telescopes the incident photon converts in a tungsten foil, which is a passive material, in a LAr-TPC this conversion happens in LAr itself, which is fully active. In this proceeding is described a plausible design for the tracker-converter detector which fulfills the constraints on conversion efficiency, angular resolution, and wide field of view. It is demonstrated how this design can provide an unprecedented angular resolution for a $\\gamma$-ray telescope, leading to a significant improvement in sensitivity and most important disclosing the possibility to detect the polarization of $\\gamma$-ray emission.

  20. Modeling ionization and recombination from low energy nuclear recoils in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Foxe, Michael P.; Hagmann, Chris; Jovanovic, Igor; Bernstein, A.; Joshi, T.; Kazkaz, K.; Mozin, Vladimir V.; Pereverzev, S. V.; Sangiorgio, Samuele; Sorensen, Peter F.

    2015-09-01

    Coherent neutrino-nucleus scattering (CNNS) is an as-yet undetected, flavor-independent neutrino interaction predicted by the Standard Model. CNNS is a flavor-blind interaction, which offers potential benefits for its use in nonproliferation (nuclear reactor monitoring) and astrophysics (supernova and solar neutrinos) applications. One challenge with detecting CNNS is the low energy deposition associated with a typical CNNS nuclear recoil. In addition, nuclear recoils are predicted to result in lower ionization yields than those produced by electron recoils of the same energy. This ratio of nuclear- and electron-induced ionization, known as the nuclear quenching factor, is unknown at energies typical for CNNS interactions in liquid xenon (LXe) and liquid argon (LAr), detector media being considered for CNNS detection. While there have been recent measurements [1] of the ionization yield from nuclear recoils in LAr, there is no universal model for nuclear quenching and ionization yield. For this reason, a Monte Carlo simulation has been developed to predict the ionization yield at sub-10 keV energies. The local ionization yield of a recoiling atom in the medium is calculated first. The ejected electrons are subsequently tracked in the electric field resulting from both the local electric charges and the externally applied drift field. The dependence of the ionization yield on the drift electric field is obtained by combining the calculated ionization yield for the initial collision cascade with the electron escape probability. An updated estimate of the CNNS signal expected in a LAr detector operated near a nuclear power reactor is presented.

  1. Performance of a liquid argon time projection chamber exposed to the CERN West Area Neutrino Facility neutrino beam

    International Nuclear Information System (INIS)

    We present the results of the first exposure of a Liquid Argon TPC to a multi-GeV neutrino beam. The data have been collected with a 50 liters ICARUS-like chamber located between the CHORUS and NOMAD experiments at the CERN West Area Neutrino Facility (WANF). We discuss both the instrumental performance of the detector and its capability to identify and reconstruct low-multiplicity neutrino interactions

  2. A Study of Nuclear Recoils in Liquid Argon Time Projection Chamber for the Direct Detection of WIMP Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Huajie [Princeton Univ., NJ (United States)

    2014-11-01

    Robust results of WIMP direct detection experiments depend on rm understandings of nuclear recoils in the detector media. This thesis documents the most comprehensive study to date on nuclear recoils in liquid argon - a strong candidate for the next generation multi-ton scale WIMP detectors. This study investigates both the energy partition from nuclear recoil energy to secondary modes (scintillation and ionization) and the pulse shape characteristics of scintillation from nuclear recoils.

  3. ArDM: a ton-scale liquid Argon experiment for direct detection of Dark Matter in the Universe

    International Nuclear Information System (INIS)

    The ArDM project aims at developing and operating large noble liquid detectors to search for direct evidence of Weakly Interacting Massive Particle (WIMP) as Dark Matter in the Universe. The initial goal is to design, assemble and operate a ∼1 ton liquid Argon prototype to demonstrate the feasibility of a ton-scale experiment with the required performance to efficiently detect and sufficiently discriminate backgrounds for a successful WIMP detection. Our design addresses the possibility to detect independently ionization and scintillation signals. In this paper, we describe this goal and the conceptual design of the detector

  4. ATLAS Heavy Ion Event Display - November 2015

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    One of the first heavy-ion collisions with stable beams recorded by ATLAS in November 2015. Tracks reconstructed from hits in the inner tracking detector are shown as orange arcs curving in the solenoidal magnetic field. The green and yellow bars indicate energy deposits in the Liquid Argon and Scintillating Tile calorimeters respectively. The beam pipe and the inner detectors are also shown.

  5. Summary of the second workshop on liquid argon time projection chamber research and development in the United States

    Science.gov (United States)

    Acciarri, R.; Adamowski, M.; Artrip, D.; Baller, B.; Bromberg, C.; Cavanna, F.; Carls, B.; Chen, H.; Deptuch, G.; Epprecht, L.; Dharmapalan, R.; Foreman, W.; Hahn, A.; Johnson, M.; Jones, B. J. P.; Junk, T.; Lang, K.; Lockwitz, S.; Marchionni, A.; Mauger, C.; Montanari, C.; Mufson, S.; Nessi, M.; Olling Back, H.; Petrillo, G.; Pordes, S.; Raaf, J.; Rebel, B.; Sinins, G.; Soderberg, M.; Spooner, N. J. C.; Stancari, M.; Strauss, T.; Terao, K.; Thorn, C.; Tope, T.; Toups, M.; Urheim, J.; Van de Water, R.; Wang, H.; Wasserman, R.; Weber, M.; Whittington, D.; Yang, T.

    2015-07-01

    The second workshop to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States was held at Fermilab on July 8-9, 2014. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in six topical plenary sessions: i) Argon Purity and Cryogenics, ii) TPC and High Voltage, iii) Electronics, Data Acquisition and Triggering, iv) Scintillation Light Detection, v) Calibration and Test Beams, and vi) Software. This document summarizes the current efforts in each of these areas. It primarily focuses on the work in the US, but also highlights work done elsewhere in the world.

  6. Summary of the second workshop on liquid argon time projection chamber research and development in the United States

    International Nuclear Information System (INIS)

    The second workshop to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States was held at Fermilab on July 8-9, 2014. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in six topical plenary sessions: i) Argon Purity and Cryogenics, ii) TPC and High Voltage, iii) Electronics, Data Acquisition and Triggering, iv) Scintillation Light Detection, v) Calibration and Test Beams, and vi) Software. This document summarizes the current efforts in each of these areas. It primarily focuses on the work in the US, but also highlights work done elsewhere in the world

  7. Summary of the Second Workshop on Liquid Argon Time Projection Chamber Research and Development in the United States

    CERN Document Server

    Acciarri, R; Artrip, D; Baller, B; Bromberg, C; Cavanna, F; Carls, B; Chen, H; Deptuch, G; Epprecht, L; Dharmapalan, R; Foreman, W; Hahn, A; Johnson, M; Jones, B J P; Junk, T; Lang, K; Lockwitz, S; Marchionni, A; Mauger, C; Montanari, C; Mufson, S; Nessi, M; Back, H Olling; Petrillo, G; Pordes, S; Raaf, J; Rebel, B; Sinins, G; Soderberg, M; Spooner, N J C; Stancari, M; Strauss, T; Terao, K; Thorn, C; Tope, T; Toups, M; Urheim, J; Van de Water, R; Wang, H; Wasserman, R; Weber, M; Whittington, D; Yang, T

    2015-01-01

    The second workshop to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States was held at Fermilab on July 8-9, 2014. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in six topical plenary sessions: $i)$ Argon Purity and Cryogenics, $ii)$ TPC and High Voltage, $iii)$ Electronics, Data Acquisition and Triggering, $iv)$ Scintillation Light Detection, $v)$ Calibration and Test Beams, and $vi)$ Software. This document summarizes the current efforts in each of these areas. It primarily focuses on the work in the US, but also highlights work done elsewhere in the world.

  8. Summary of the Second Workshop on Liquid Argon Time Projection Chamber Research and Development in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); et al.

    2015-04-21

    The second workshop to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States was held at Fermilab on July 8-9, 2014. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in six topical plenary sessions: i) Argon Purity and Cryogenics, ii) TPC and High Voltage, iii) Electronics, Data Acquisition and Triggering, iv) Scintillation Light Detection, v) Calibration and Test Beams, and vi) Software. This document summarizes the current efforts in each of these areas. It primarily focuses on the work in the US, but also highlights work done elsewhere in the world.

  9. Performance of the ATLAS hadronic end-cap calorimeter in beam tests

    Energy Technology Data Exchange (ETDEWEB)

    Dowler, B.; Pinfold, J.; Soukup, J.; Vincter, M.; Cheplakov, A.; Datskov, V.; Fedorov, A.; Javadov, N.; Kalinnikov, V.; Kakurin, S.; Kazarinov, M.; Kukhtin, V.; Ladygin, E.; Lazarev, A.; Neganov, A.; Pisarev, I.; Serochkin, E.; Shilov, S.; Shalyugin, A.; Usov, Yu.; Ban, J.; Bruncko, D.; Chytracek, R.; Jusko, A.; Kladiva, E.; Strizenec, P.; Gaertner, V.; Hiebel, S.; Hohlfeld, M.; Jakobs, K.; Koepke, L.; Marschalkowski, E.; Meder, D.; Othegraven, R.; Schaefer, U.; Thomas, J.; Walkowiak, W.; Zeitnitz, C.; Leroy, C.; Mazini, R.; Mehdiyev, R.; Akimov, A.; Blagov, M.; Komar, A.; Snesarev, A.; Speransky, M.; Sulin, V.; Yakimenko, M.; Aderholz, M.; Brettel, H.; Cwienk, W.; Dulny, B.; Fent, J.; Fischer, A.; Haberer, W.; Huber, J.; Huber, R.; Karev, A.; Kiryunin, A.; Kobler, T.; Kurchaninov, L.; Laskus, H.; Lindenmayer, M.; Mooshofer, P.; Oberlack, H.; Salihagic, D.; Schacht, P. E-mail: phys@mppmn.mpg.de; Stenzel, H.; Striegel, D.; Tribanek, W.; Chekulaev, S.; Denisov, S.; Levitsky, M.; Minaenko, A.; Mitrofanov, G.; Moiseev, A.; Pleskatch, A.; Sytnik, V.; Benoit, P.; Hoyle, K.W.; Honma, A.; Maharaj, R.; Oram, C.J.; Pattyn, E.W.; Rosvick, M.; Sbarra, C.; Wellisch, H-P.; Wielers, M.; Birney, P.S.; Dobbs, M.; Fincke-Keeler, M.; Fortin, D.; Hodges, T.A.; Keeler, R.K.; Langstaff, R.; Lefebvre, M.; Lenckowski, M.; McPherson, R.; O' Neil, D.C.; Forbush, D.; Mockett, P.; Toevs, F.; Braun, H.M.; Thadome, J

    2002-04-11

    Modules of the ATLAS liquid argon Hadronic End-cap Calorimeter (HEC) were exposed to beams of electrons, muons and pions in the energy range 6{<=}E{<=}200 GeV at the CERN SPS. A description of the HEC and of the beam test setup are given. Results on the energy response and resolution are presented and compared with simulations. The ATLAS energy resolution for jets in the end-cap region is inferred and meets the ATLAS requirements.

  10. Performance of the ATLAS hadronic end-cap calorimeter in beam tests

    International Nuclear Information System (INIS)

    Modules of the ATLAS liquid argon Hadronic End-cap Calorimeter (HEC) were exposed to beams of electrons, muons and pions in the energy range 6≤E≤200 GeV at the CERN SPS. A description of the HEC and of the beam test setup are given. Results on the energy response and resolution are presented and compared with simulations. The ATLAS energy resolution for jets in the end-cap region is inferred and meets the ATLAS requirements

  11. Performance of the ATLAS Hadronic End-Cap Calorimeter in Beam Tests

    CERN Document Server

    Dowler, B; Soukup, J; Vincter, M G; Cheplakov, A P; Datskov, V I; Fedorov, A; Javadov, N; Kalinnikov, V; Kakurin, S; Kazarinov, M; Kukhtin, V; Ladygin, E; Lazarev, A B; Neganov, A B; Pisarev, I; Serochkin, E; Shilov, S N; Shalyugin, A N; Usov, Yu; Bán, J; Bruncko, Dusan; Chytracek, R; Jusko, A; Kladiva, E; Strízenec, P; Gärtner, V; Hiebel, S; Hohlfeld, M; Jakobs, K; Köpke, L; Marschalkowski, E; Meder, D; Othegraven, R; Schäfer, U; Thomas, J; Walkowiak, W; Zeitnitz, C; Leroy, C; Mazini, R; Mehdiyev, R; Akimov, A; Blagov, M I; Komar, A; Snesarev, A A; Speransky, M N; Sulin, V; Yakimenko, M; Aderholz, M; Brettel, H; Cwienk, W D; Dulny, B; Fent, J; Fischer, A; Haberer, W; Huber, J; Huber, R; Karev, A; Kiryunin, A E; Kobler, T; Kurchaninov, L L; Laskus, H; Lindenmayer, M; Mooshofer, P; Oberlack, H; Salihagic, D; Schacht, P; Stenzel, H; Striegel, D; Tribanek, W; Chekulaev, S V; Denisov, S; Levitsky, M; Minaenko, A A; Mitrofanov, G Ya; Moiseev, A; Pleskatch, A; Sytnik, V V; Benoit, P; Hoyle, K; Honma, A; Maharaj, R; Oram, C J; Pattyn, E; Rosvick, M; Sbarra, C; Wellisch, H P; Wielers, M; Birney, P; Dobbs, M; Fincke-Keeler, M; Fortin, D; Hodges, T; Keeler, Richard K; Langstaf, R; Lefebvre, M; Lenckowski, M; McPherson, R A; O'Neil, D C; Forbush, D

    2002-01-01

    Modules of the ATLAS liquid argon Hadronic End-cap calorimeter (HEC) were exposed to beams of electrons, muons and pions in the energy range 6GeVATLAS energy resolution for jets in the end-cap region is inferred and meets the ATLAS requirements.

  12. Optical readout tracking detector concept using secondary scintillation from liquid argon generated by a thick gas electron multiplier

    CERN Document Server

    Lightfoot, P K; Mavrokoridis, K; Ramachers, Y A; Spooner, N J C

    2009-01-01

    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 an immersed SiPM device coated in the waveshifter tetraphenyl butadiene (TPB), the emission spectrum peaked at 460nm in the high quantum efficiency region of the device. For a SiPM over-voltage of 1V, a TGEM voltage of 9.91KV, and a drift field of 2.5KV/cm, a total of 62 photoelectrons were produced at the SiPM device per Fe-55 event, corresponding to an estimated gain of 150 photoelectrons per drifted electron.

  13. A Factor of Four Increase in Attenuation Length of Dipped Lightguides for Liquid Argon TPCs Through Improved Coating

    CERN Document Server

    Moss, Z; Bugel, L; Conrad, J M; Sachdev, K; Toups, M; Wongjirad, T

    2016-01-01

    This paper describes new techniques for producing lightguides for detection of scintillation light in liquid argon time projection chambers. These can be used in future neutrino experiments such as SBND and DUNE. These new results build on a dipped-coating technique that was previously reported and is reviewed here. The improvements to the approach indicate a factor of four improvement in attenuation length of the lightguides compared to past studies. The measured attenuation lengths, which are >2 m, are consistent with the bulk attenuation length of the material. Schematics for a mechanical dipping system are provided in this paper. This system is shown to result in coatings with < 10% variations

  14. Measurement of the two-photon absorption cross-section of liquid argon with a time projection chamber

    CERN Document Server

    Badhrees, I; Kreslo, I; Messina, M; Moser, U; Rossi, B; Weber, M S; Zeller, M; Altucci, C; Amoruso, S; Bruzzese, R; Velotta, R

    2010-01-01

    This paper reports on laser-induced multiphoton ionization at 266 nm of liquid argon in a time projection chamber (LAr TPC) detector. The electron signal produced by the laser beam is a formidable tool for the calibration and monitoring of next-generation large-mass LAr TPCs. The detector that we designed and tested allowed us to measure the two-photon absorption cross-section of LAr with unprecedented accuracy and precision: $\\sigma_ex$=(1.24$\\pm$0.10stat $\\pm$0.30syst)$\\times$10^{-56} cm$^4$s{-1}.

  15. Delayed light emission of Tetraphenyl-butadiene excited by liquid argon scintillation light. Current status and future plans

    Science.gov (United States)

    Segreto, E.; Machado, A. A.; Araujo, W.; Teixeira, V.

    2016-02-01

    Tetraphenyl-butadiene is the wavelength shifter most widely used in combination with liquid argon. The latter emits scintillation photons with a wavelength of 127 nm that need to be downshifted to be detected by photomultipliers with glass or quartz windows. Tetraphenyl-butadiene has been demonstrated to have an extremely high conversion efficiency, possibly higher than 100% for 127 nm photons, while there is no precise information about the time dependence of its emission. It is usually assumed to be exponentially decaying with a characteristic time of the order of one ns, as an extrapolation from measurements with exciting radiation in the near UV . This work shows that tetraphenyl-butadiene, when excited by 127 nm photons, re-emits photons not only with a very short decay time, but also with slower ones due to triplet states de-excitations. This fact can strongly contribute to clarifying the anomalies in liquid-argon scintillation light reported in the literature since the 1970s. Precision measurements of the properties of TPB, when excited by Vacuum Ultra Violet photons are being carried on at the Brazilian Synchrotron Light Laboratory in Campinas (State of São Paulo).

  16. Status of ArDM-1t: First observations from operation with a full ton-scale liquid argon target

    CERN Document Server

    Calvo, J; Daniel, M; Degunda, U; Di Luise, S; Epprecht, L; Gendotti, A; Horikawa, S; Knecht, L; Montes, B; Mu, W; Munoz, M; Murphy, S; Natterer, G; Nguyen, K; Nikolics, K; Periale, L; Regenfus, C; Romero, L; Rubbia, A; Santorelli, R; Sergiampietri, F; Sgalaberna, D; Viant, T; Wu, S

    2015-01-01

    ArDM-1t is the first operating ton-scale liquid argon detector for direct search of Dark Matter particles. Developed at CERN as Recognized Experiment RE18, the experiment has been approved in 2010 to be installed in the Spanish underground site LSC (Laboratorio Subterraneo de Canfranc). Under the label of LSC EXP-08-2010 the ArDM detector underwent an intensive period of technical completion and safety approval until the recent filling of the target vessel with almost 2 ton of liquid argon. This report describes the experimental achievements during commissioning of ArDM and the transition into a stage of first physics data taking in single phase operational mode. We present preliminary observations from this run. A first indication for the background discrimination power of LAr detectors at the ton-scale is shown. We present an outlook for completing the detector with the electric drift field and upgrade of the scintillation light readout system with novel detector modules based on SiPMs in order to improve t...

  17. Calorimetry triggering in ATLAS

    International Nuclear Information System (INIS)

    The ATLAS experiment is preparing for data taking at 14 TeV collision energy. A rich discovery physics program is being prepared in addition to the detailed study of Standard Model processes which will be produced in abundance. The ATLAS multi-level trigger system is designed to accept one event in 2 | 105 to enable the selection of rare and unusual physics events. The ATLAS calorimeter system is a precise instrument, which includes liquid Argon electro-magnetic and hadronic components as well as a scintillator-tile hadronic calorimeter. All these components are used in the various levels of the trigger system. A wide physics coverage is ensured by inclusively selecting events with candidate electrons, photons, taus, jets or those with large missing transverse energy. The commissioning of the trigger system is being performed with cosmic ray events and by replaying simulated Monte Carlo events through the trigger and data acquisition system.

  18. ATLAS recognises its best suppliers

    CERN Multimedia

    Jenni, P

    The ATLAS Collaboration has recently rewarded two of its suppliers in the construction of very major detector components, fabricated in Japan. The ATLAS Supplier Award in recognition of excellent supplier performance was attributed on 2nd September 2002 during a ceremony in Hall 180 to Kawasaki Heavy Industries, while Toshiba Corporation received the award two months before at their headquarters in Japan. The ATLAS experiment will become a reality thanks to a large international collaboration partnership. The industrial suppliers for the components all over the world play a major role in the construction of this gigantic jigsaw for the LHC. And sometimes they perform so well, that their work deserves specially to be recognised. This is the case for Kawasaki Heavy Industries and Toshiba Corporation, producers of the Liquid Argon Barrel Cryostat and of the Superconducting Central Solenoid, respectively. With these awards, the ATLAS Collaboration wants to congratulate Kawasaki and Toshiba for fulfilling the hi...

  19. Measuring Muon-Neutrino Charged-Current Differential Cross Sections with a Liquid Argon Time Projection Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Spitz, Joshua B. [Yale Univ., New Haven, CT (United States)

    2011-01-01

    More than 80 years after its proposed existence, the neutrino remains largely mysterious and elusive. Precision measurements of the neutrino's properties are just now beginning to take place. Such measurements are required in order to determine the mass of the neutrino, how many neutrinos there are, if neutrinos are different than anti-neutrinos, and more. Muon-neutrino charged-current differential cross sections on an argon target in terms of the outgoing muon momentum and angle are presented. The measurements have been taken with the ArgoNeuT Liquid Argon Time Projection Chamber (LArTPC) experiment. ArgoNeuT is the first LArTPC to ever take data in a low energy neutrino beam, having collected thousands of neutrino and anti-neutrino events in the NuMI beamline at Fermilab. The results are relevant for long baseline neutrino oscillation experiments searching for non-zero $\\theta_{13}$, CP-violation in the lepton sector, and the sign of the neutrino mass hierarchy, among other things. Furthermore, the differential cross sections are important for understanding the nature of the neutrino-nucleus interaction in general. These measurements represent a significant step forward for LArTPC technology as they are among the first neutrino physics results with such a device.

  20. Performance evaluation of a liquid tin anode solid oxide fuel cell operating under hydrogen, argon and coal

    Science.gov (United States)

    Khurana, Sanchit; LaBarbera, Mark; Fedkin, Mark V.; Lvov, Serguei N.; Abernathy, Harry; Gerdes, Kirk

    2015-01-01

    A liquid tin anode solid oxide fuel cell is constructed and investigated under different operating conditions. Electrochemical Impedance Spectroscopy (EIS) is used to reflect the effect of fuel feed as the EIS spectra changes significantly on switching the fuel from argon to hydrogen. A cathode symmetric cell is used to separate the impedance from the two electrodes, and the results indicate that a major contribution to the charge-transfer and mass-transfer impedance arises from the anode. The OCP of 0.841 V for the cell operating under argon as a metal-air battery indicates the formation of a SnO2 layer at the electrolyte/anode interface. The increase in the OCP to 1.1 V for the hydrogen fueled cell shows that H2 reduces the SnO2 film effectively. The effective diffusion coefficients are calculated using the Warburg element in the equivalent circuit model for the experimental EIS data, and the values of 1.9 10-3 cm2 s-1 at 700 °C, 2.3 10-3 cm2 s-1 at 800 °C and 3.5 10-3 cm2 s-1 at 900 °C indicate the system was influenced by diffusion of hydrogen in the system. Further, the performance degradation over time is attributed to the irreversible conversion of Sn to SnO2 resulting from galvanic polarization.

  1. Measuring Muon-Neutrino Charged-Current Differential Cross Sections with a Liquid Argon Time Projection Chamber

    Science.gov (United States)

    Spitz, Joshua B.

    More than 80 years after its proposed existence, the neutrino remains largely mysterious and elusive. Precision measurements of the neutrino's properties are just now beginning to take place. Such measurements are required in order to determine the mass of the neutrino, how many neutrinos there are, if neutrinos are different than anti-neutrinos, and more. Muon-neutrino charged-current differential cross sections on an argon target in terms of the outgoing muon momentum and angle are presented. The measurements have been taken with the ArgoNeuT Liquid Argon Time Projection Chamber (LArTPC) experiment. ArgoNeuT is the first LArTPC to ever take data in a low energy neutrino beam, having collected thousands of neutrino and anti-neutrino events in the NuMI beamline at Fermi-lab. The results are relevant for long baseline neutrino oscillation experiments searching for non-zero theta13, CP-violation in the lepton sector, and the sign of the neutrino mass hierarchy, among other things. Furthermore, the differential cross sections are important for understanding the nature of the neutrino-nucleus interaction in general. These measurements represent a significant step forward for LArTPC technology as they are among the first neutrino physics results with such a device.

  2. Tests of PMT Signal Read-out in a Liquid Argon Dark Matter Detector with a New Fast Waveform Digitizer

    CERN Document Server

    Acciarri, R; Cavanna, F; Cortopassi, A; D'Incecco, M; Mini, G; Pietropaolo, F; Romboli, A; Segreto, E; Szelc, A M

    2012-01-01

    The CAEN V1751 is a new generation of Waveform Digitizer recently introduced by CAEN SpA. Its features, i.e. 8 Channels per board, 10 bit, 1 GS/s Flash ADC Waveform Digitizer (or 4 channel, 10 bit, 2 GS/s Flash ADC Waveform Digitizer - Dual Edge Sampling mode) with threshold and Auto-Trigger capabilities provides a very good (relatively low-cost) solution for data acquisition in Dark Matter searches using PMTs to detect scintillation light in liquid argon. The board was tested by operating it in real experimental conditions and by comparing it with a state of the art digital oscilloscope. We find that the sampling at 1 or 2 GS/s is appropriate for the reconstruction of the fast component of the scintillation light in argon (characteristic time of about 6-7 ns) and the extended dynamic range, after a small customization, allows for the detection of signals in the range of energy needed. The bandwidth is found to be adequate and the intrinsic noise is very low.

  3. Depleted Argon from Underground Sources

    International Nuclear Information System (INIS)

    Argon is a strong scintillator and an ideal target for Dark Matter detection; however 39Ar contamination in atmospheric argon from cosmic ray interactions limits the size of liquid argon dark matter detectors due to pile-up. Argon from deep underground is depleted in 39Ar due to the cosmic ray shielding of the earth. In Cortez, Colorado, a CO2 well has been discovered to contain approximately 600 ppm of argon as a contamination in the CO2. We first concentrate the argon locally to 3% in an Ar, N2, and He mixture, from the CO2 through chromatographic gas separation, and then the N2 and He will be removed by continuous distillation to purify the argon. We have collected 26 kg of argon from the CO2 facility and a cryogenic distillation column is under construction at Fermilab to further purify the argon.

  4. Attenuation of vacuum ultraviolet light in pure and xenon-doped liquid argon - an approach to an assignment of the near-infrared emission from the mixture

    CERN Document Server

    Neumeier, A; Himpsl, A; Oberauer, L; Potzel, W; Schönert, S; Ulrich, A

    2015-01-01

    Results of transmission experiments of vacuum ultraviolet light through a 11.6 cm long cell filled with pure and xenon-doped liquid argon are described. Pure liquid argon shows no attenuation down to the experimental short-wavelength cut-off at 118nm. Based on a conservative approach, a lower limit of 1.10 m for the attenuation length of its own scintillation light could be derived. Adding xenon to liquid argon at concentrations on the order of parts per million leads to strong xenon-related absorption features which are used for a tentative assignment of the recently found near-infrared emission observed in electron-beam excited liquid argon-xenon mixtures. Two of the three absorption features can be explained by perturbed xenon transitions and the third one by a trapped exciton (Wannier-Mott) impurity state. A calibration curve connecting the equivalent width of the absorption line at 140 nm with xenon concentration is provided.

  5. Study, construction and test of a liquid argon preshower detector for the LHC

    International Nuclear Information System (INIS)

    The CERN is planning the construction of a new particle collider, the LHC, a p-p collider which operational energies will be greater than 1 TeV. A position detector or preshower detector will form a part of the Atlas detector which will analyze the interaction products; it will be used to spatially identify the disintegration of the Higgs boson, the signature of the Higgs mechanism into two photons. It will also provide an energy correction for the electromagnetic calorimeter. This paper gives simulation results for its spatial and angular resolution as well as the energy resolution achieved for the electromagnetic calorimeter when the preshower's energy correction is applied. A prototype and beam tests are presented; results are compared with those of Monte Carlo simulations. 110 fig., 31 ref

  6. ATLAS

    Data.gov (United States)

    Federal Laboratory Consortium — ATLAS is a particle physics experiment at the Large Hadron Collider at CERN, the European Organization for Nuclear Research. Scientists from Brookhaven have played...

  7. Nuclear recoil detection in liquid argon using a two-phase CRAD and DD neutron generator

    International Nuclear Information System (INIS)

    The detection of nuclear recoils in noble liquids using neutron elastic scattering off nuclei is relevant in the field of calibration of rare-event detectors for dark matter search and coherent neutrino-nucleus scattering experiments. We present here the first results on nuclear recoil detection in liquid Ar, using a two-phase Cryogenic Avalanche Detector (CRAD) and DD neutron generator. The technique to select the nuclear recoils for backward neutron scattering has been demonstrated

  8. Performance of a SensL-30035-16P silicon photomultiplier array at liquid argon temperature

    International Nuclear Information System (INIS)

    Next generation multi-ton scale noble liquid experiments have the unique opportunity to discover dark matter particles at the TeV scale, reaching the sensitivity of 10−48 cm2 in the WIMP nucleon scattering cross-section. A prerequisite will be the reduction of radiogenic background sources to negligible levels. This is only possible if ultra-pure high efficiency photosensors are available for the scintillation light readout. Current experiments (e.g. Xenon, LUX, Darkside, ArDM) use cryogenic PMTs as photosensors. An attractive alternative is represented by silicon photomultiplier arrays (SiPM arrays), which show unrivalled performances in single photon detection. This paper reports on the performance of the SensL-ArrayB-30035-16P SiPM array and a custom made cryogenic front-end board at the liquid argon temperature. Its performance at VOV=3.5 V, where the PDE is maximal, are very promising in terms of SPE resolution (about 8%), dark rate (about 250 Hz) and correlated pulses (30%)

  9. Optical Readout of a Two Phase Liquid Argon TPC using CCD Camera and TGEMs

    CERN Document Server

    Mavrokoridis, K; Carroll, J; Lazos, M; McCormick, K J; Smith, N A; Touramanis, C; Walker, J

    2014-01-01

    This paper presents a preliminary study into the use of CCDs to image secondary scintillation light generated by Thick Gas Electron Multipliers (TGEMs) in a two phase LAr TPC. A Sony ICX285AL CCD chip was mounted above a double TGEM in the gas phase of a 40 litre two-phase LAr TPC with the majority of the camera electronics positioned externally via a feedthrough. An Am-241 source was mounted on a rotatable motion feedthrough allowing the positioning of the alpha source either inside or outside of the field cage. Developed for and incorporated into the TPC design was a novel high voltage feedthrough featuring LAr insulation. Furthermore, a range of webcams were tested for operation in cryogenics as an internal detector monitoring tool. Of the range of webcams tested the Microsoft HD-3000 (model no:1456) webcam was found to be superior in terms of noise and lowest operating temperature. In ambient temperature and atmospheric pressure 1 ppm pure argon gas, the TGEM gain was approximately 1000 and using a 1 msec...

  10. Supernova neutrino signals by liquid Argon detector and neutrino magnetic moment

    CERN Document Server

    Yoshida, Takashi; Kimura, Keiichi; Kawagoe, Shio; Kajino, Toshitaka; Yokomakura, Hidekazu

    2011-01-01

    We study electron-neutrino and electron-antineutrino signals from a supernova with strong magnetic field detected by a 100 kton liquid Ar detector. The change of neutrino flavors by resonant spin-flavor conversions, matter effects, and neutrino self-interactions are taken into account. Different neutrino signals, characterized by neutronization burst event and the total event numbers of electron-neutrinos and electron-antineutrinos, are expected with different neutrino oscillation parameters and neutrino magnetic moment. Observations of supernova neutrino signals by a 100 kton liquid Ar detector would constrain oscillation parameters as well as neutrino magnetic moment in either normal and inverted mass hierarchies.

  11. ATLAS's superconducting solenoid takes up position

    CERN Multimedia

    2004-01-01

    The ATLAS superconducting solenoid was moved to its final destination on 16 January. It has taken up position opposite the ATLAS liquid argon barrel cryostat, which will house the electromagnetic calorimeter. All that remains to do now is to slide it into the insulation vacuum, this will be done in the next few weeks. Built by Toshiba, under responsibility of KEK in Japan, the central solenoid is 2.4 metres in diameter, 5.3 metres long and weighs 5.5 tonnes. "It will provide an axial magnetic field of 2 Tesla that will deflect particles inside the inner detector," as Roger Ruber, on-site project coordinator, explains. The inner detector, which consists of three sub-detectors, will be installed inside the solenoid later. The solenoid during one of the transport operations. Securely attached to the overhead travelling crane, the solenoid is situated in front of the opening to the liquid argon calorimeter, it will be inserted soon.

  12. Performance and stability tests of bare high purity germanium detectors in liquid argon for the GERDA experiment

    International Nuclear Information System (INIS)

    GERDA will search for neutrinoless double beta decay of 76Ge by using a novel approach of bare germanium detectors in liquid argon (LAr). Enriched germanium detectors from the previous Heidelberg-Moscow and IGEX experiments have been reprocessed and will be deployed in GERDA Phase-I. At the center of this thesis project is the study of the performance of bare germanium detectors in cryogenic liquids. Identical detector performance as in vacuum cryostats (2.2 keV FWHM at 1.3 MeV) was achieved in cryogenic liquids with a new low-mass detector assembly and contacts. One major result is the discovery of a radiation induced leakage current (LC) increase when operating bare detectors with standard passivation layers in LAr. Charge collection and build-up on the passivation layer were identified as the origin of the LC increase. It was found that diodes without passivation do not exhibit this feature. Three month-long stable operation in LAr at ∝ 5 pA LC under periodic gamma irradiation demonstrated the suitability of the modi ed detector design. Based on these results, all Phase-I detectors were reprocessed without passivation layer and subsequently successfully characterized in LAr in the GERDA underground Detector Laboratory. The mass loss during the reprocessing was ∝300 g out of 17.9 kg and the exposure above ground ∝ 5 days. This results in a negligible cosmogenic background increase of ∝ 5.10-4 cts/(keV.kg.y) at 76Ge Qβ for 60Co and 68Ge. (orig.)

  13. Performance and stability tests of bare high purity germanium detectors in liquid argon for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Barnabe Heider, Marik

    2009-05-27

    GERDA will search for neutrinoless double beta decay of {sup 76}Ge by using a novel approach of bare germanium detectors in liquid argon (LAr). Enriched germanium detectors from the previous Heidelberg-Moscow and IGEX experiments have been reprocessed and will be deployed in GERDA Phase-I. At the center of this thesis project is the study of the performance of bare germanium detectors in cryogenic liquids. Identical detector performance as in vacuum cryostats (2.2 keV FWHM at 1.3 MeV) was achieved in cryogenic liquids with a new low-mass detector assembly and contacts. One major result is the discovery of a radiation induced leakage current (LC) increase when operating bare detectors with standard passivation layers in LAr. Charge collection and build-up on the passivation layer were identified as the origin of the LC increase. It was found that diodes without passivation do not exhibit this feature. Three month-long stable operation in LAr at {proportional_to} 5 pA LC under periodic gamma irradiation demonstrated the suitability of the modi ed detector design. Based on these results, all Phase-I detectors were reprocessed without passivation layer and subsequently successfully characterized in LAr in the GERDA underground Detector Laboratory. The mass loss during the reprocessing was {proportional_to}300 g out of 17.9 kg and the exposure above ground {proportional_to} 5 days. This results in a negligible cosmogenic background increase of {proportional_to} 5.10{sup -4} cts/(keV.kg.y) at {sup 76}Ge Q{sub {beta}}{sub {beta}} for {sup 60}Co and {sup 68}Ge. (orig.)

  14. Many-body and quantum effects in the surface tension and surface energy of liquid neon and argon using the Fowler’s approximation

    International Nuclear Information System (INIS)

    Highlights: ► Fowler’s expression for calculation of the surface tension and energy has been used. ► Quantum corrections considered using the FH and WK approaches for liquid neon. ► Two simple three-body potentials used for a two-body potential of argon. ► Improvement in the results obtained by including the quantum and three-body effects. - Abstract: The Fowler’s expression for calculation of the reduced surface tension and surface energy has been used with Lennard–Jones (LJ) and two-body Hartree–Fock dispersion (HFD)-like potentials for neon and argon, respectively. The required radial distribution functions (RDFs) have been used from two recently determined expressions in the literature and a new equation proposed in this work. Quantum corrections for neon system have been considered using the Feynman–Hibbs (FH) and Wigner–Kirkwood (WK) approaches. To take many-body forces into account for argon system, the simple three-body potentials of Wang and Sadus (2006) and Hauschild and Prausnitz (1993) used with the HFD-like potential without requiring an expensive three-body calculation. The results show that the quantum and three-body effects improve the prediction of the surface tension of liquid neon and argon using the Fowler’s expression.

  15. Study of infrared scintillations in gaseous and liquid argon - Part I: methodology and time measurements

    CERN Document Server

    Bondar, A; Dolgov, A; Grebenuk, A; Shemyakina, E; Sokolov, A

    2012-01-01

    A methodology to measure Near Infrared (NIR) scintillations in gaseous and liquid Ar, using Geiger-mode APDs (GAPDs) sensitive in the NIR and pulsed X-ray irradiation, is described. This study has been triggered by the development of Cryogenic Avalanche Detectors (CRADs) with optical readout in the NIR using combined THGEM/GAPD multiplier, which may come to be in demand in coherent neutrino-nucleus scattering and dark matter search experiments. A new approach to measure the NIR scintillation yield at cryogenic temperatures has been developed, namely using GAPDs in single photoelectron counting mode with time resolution. The time structure of NIR scintillations and their light yield were measured both for primary scintillations and that of secondary at moderate electric fields (electroluminescence), in gaseous and liquid Ar.

  16. Light Readout for a 1 ton Liquid Argon Dark Matter Detector

    CERN Document Server

    Boccone, Vittorio; Baudis, Laura; Otyugova, Polina; Regenfus, Christian

    2010-01-01

    Evidence for dark matter (DM) has been reported using astronomical observations in systems such as the Bullet cluster. Weakly interactive massive particles (WIMPs), in particular the lightest neutralino, are the most popular DM candidates within the Minimal Supersymmetric Standard Model (MSSM). Many groups in the world are focussing their attention on the direct detection of DM in the laboratory. The detectors should have large target masses and excellent noise rejection capabilities because of the small cross section between DM and ordinary matter (σWIMP−nucleon < 4 · 10−8 pb). Noble liquids are today considered to be one of the best options for large-size DM experiments, as they have a relatively low ionization energy, good scintillation properties and long electron lifetime. Moreover noble liquid detectors are easily scalable to large masses. This thesis deals with the development of a large (1 ton) LAr WIMP detector (ArDM) which could measure simultaneously light and charge from the scintilla...

  17. Liquid-Vapor Argon Isotope Fractionation from the Triple Point to the Critical Point

    DEFF Research Database (Denmark)

    Phillips, J. T.; Linderstrøm-Lang, C. U.; Bigeleisen, J.

    1972-01-01

    twice the statistical scatter of the present data, the present results for the lnα are systematically 5% lower than calculations from vapor pressure data. It is shown that T2 lnα is a linear function of (ρc−ρg), the density difference between the liquid and vapor, in the range 84–120°K. The......The statistical thermodynamic treatment of the equilibrium between a nonideal liquid mixture of isotopes and a vapor phase is extended to include isotope effects on the equation of state of the gas. The result is particularly simple when the isotopic partition functions in a given phase are...... compared at the same molar volume. The isotope fractionation factor α for 36Ar∕40Ar between liquid and vapor has been measured from the triple point to the critical temperature. The results are compared with previous vapor pressure data, which cover the range 84–102°K. Although the agreement is within...

  18. Study of infrared scintillations in gaseous and liquid argon - Part II: light yield and possible applications

    CERN Document Server

    Bondar, A; Dolgov, A; Grebenuk, A; Peleganchuk, S; Shekhtman, V Porosev L; Shemyakina, E; Sokolov, A

    2012-01-01

    We present here a comprehensive study of the light yield of primary and secondary scintillations produced in gaseous and liquid Ar in the near infrared (NIR) and visible region, at cryogenic temperatures. The measurements were performed using Geiger-mode avalanche photodiodes (GAPDs) and pulsed X-ray irradiation. The primary scintillation yield of the fast emission component in gaseous Ar was found to be independent of temperature in the range of 87-160 K; it amounted to 17000+/-3000 photon/MeV in the NIR in the range of 690-1000 nm. In liquid Ar at 87 K, the primary scintillation yield of the fast component was considerably reduced, amounting to 510+/-90 photon/MeV, in the range of 400-1000 nm. Proportional NIR scintillations (electroluminescence) in gaseous Ar were also observed; their amplification parameter at 160 K was measured to be 13 photons per drifting electron per kV. No proportional scintillations were observed in liquid Ar up to the electric fields of 30 kV/cm. The applications of NIR scintillati...

  19. The ATLAS Forward Calorimeter

    Science.gov (United States)

    Artamonov, A.; Bailey, D.; Belanger, G.; Cadabeschi, M.; Chen, T.-Y.; Epshteyn, V.; Gorbounov, P.; Joo, K. K.; Khakzad, M.; Khovanskiy, V.; Krieger, P.; Loch, P.; Mayer, J.; Neuheimer, E.; Oakham, F. G.; O'Neill, M.; Orr, R. S.; Qi, M.; Rutherfoord, J.; Savine, A.; Schram, M.; Shatalov, P.; Shaver, L.; Shupe, M.; Stairs, G.; Strickland, V.; Tompkins, D.; Tsukerman, I.; Vincent, K.

    2008-02-01

    Forward calorimeters, located near the incident beams, complete the nearly 4π coverage for high pT particles resulting from proton-proton collisions in the ATLAS detector at the Large Hadron Collider at CERN. Both the technology and the deployment of the forward calorimeters in ATLAS are novel. The liquid argon rod/tube electrode structure for the forward calorimeters was invented specifically for applications in high rate environments. The placement of the forward calorimeters adjacent to the other calorimeters relatively close to the interaction point provides several advantages including nearly seamless calorimetry and natural shielding for the muon system. The forward calorimeter performance requirements are driven by events with missing ET and tagging jets.

  20. Background reduction at low energies with BEGe detector operated in liquid argon using the GERDA-LArGe facility

    International Nuclear Information System (INIS)

    LArGe is a low background test facility used for proving innovative approaches to background reduction in support of the neutrinoless double beta decay experiment Gerda. These approaches include an anti-Compton veto using scintillation light detection from liquid argon, as well as a novel pulse shape discrimination method exploiting the characteristic electrical field distribution inside BEGe detectors. The latter technique can identify single-site events (typical for double beta decays) and efficiently reject multi-site events (typical for backgrounds from gamma-ray interactions), as well as different types of background events from detector surfaces. While the main focus of the LArGe facility is to assist with reaching the goal of Gerda - improving the sensitivity for 76Ge neutrinoless double beta decay search, reducing the background at low energies and lowering the energy threshold is also of interest. In particular such efforts can be potentially relevant for search of dark matter or low energy neutrino interactions. In this talk I present the experimental measurement of the low energy region with a BEGe detector operated in LArGe with the application of powerful background suppression methods. The performance will be compared to that of some dedicated dark matter detection experiments.

  1. Background reduction at low energies with BEGe detector operated in liquid argon using the GERDA-LArGe facility

    Energy Technology Data Exchange (ETDEWEB)

    Budjas, Dusan [Physik-Department E15, Technische Universitaet Muenchen (Germany); Collaboration: GERDA-Collaboration

    2014-07-01

    LArGe is a low background test facility used for proving innovative approaches to background reduction in support of the neutrinoless double beta decay experiment Gerda. These approaches include an anti-Compton veto using scintillation light detection from liquid argon, as well as a novel pulse shape discrimination method exploiting the characteristic electrical field distribution inside BEGe detectors. The latter technique can identify single-site events (typical for double beta decays) and efficiently reject multi-site events (typical for backgrounds from gamma-ray interactions), as well as different types of background events from detector surfaces. While the main focus of the LArGe facility is to assist with reaching the goal of Gerda - improving the sensitivity for {sup 76}Ge neutrinoless double beta decay search, reducing the background at low energies and lowering the energy threshold is also of interest. In particular such efforts can be potentially relevant for search of dark matter or low energy neutrino interactions. In this talk I present the experimental measurement of the low energy region with a BEGe detector operated in LArGe with the application of powerful background suppression methods. The performance will be compared to that of some dedicated dark matter detection experiments.

  2. Investigation of n{sup +} surface events in HPGe detectors for liquid argon background rejection in GERDA

    Energy Technology Data Exchange (ETDEWEB)

    Lehnert, Bjoern [TU-Dresden, Dresden (Germany); Collaboration: GERDA-Collaboration

    2015-07-01

    The GERDA experiment is searching for neutrinoless double beta decay (0νββ) in {sup 76}Ge using an array of germanium detectors immersed in liquid argon (LAr). Phase II of the experiment aims to improve the background level by a factor 10 in order to reach 10{sup -3} counts / (kg.keV.yr). A strong suppression technique is required to suppress the intrinsic LAr background of {sup 42}Ar/{sup 42}K. 30 newly produced p-type Broad Energy Germanium (BEGe) detectors will be deployed in Phase II. The n{sup +} electrode of the GERDA BEGe detectors is covering 96-98 % of the surface and is between 0.5 and 1.2 mm thick. Betas from the {sup 42}K decay can penetrated the detector surface and deposit energies within the 0νββ region. Experiences from GERDA Phase I show that these surface events are the dominate background component without suppression. Energy depositions inside the n{sup +} layer create pulse shapes that are slower than those from interactions in the bulk. This talk presents a rejection technique for those events. The signal development inside the n{sup +} layer is modeled and applied in Geant4 Monte Carlo simulations. The simulations are compared with data for {sup 241}Am and {sup 90}Sr calibration source measurements. The suppression capabilities are extrapolated for {sup 42}K in GERDA Phase II.

  3. Status report on an engineering design study of hermetic liquid argon calorimetry for the SSC [Superconducting Super Collider

    International Nuclear Information System (INIS)

    There is general recognition that engineering issues are critical to the viability of liquid argon calorimetry (LAC) at the Superconducting Super Collider (SSC). We have undertaken to quantitatively address these issues and, if possible, perform a preliminary design of a ''proof of principle'' LAC for SSC. To establish LAC as viable at SSC, we must demonstrate that the physics performance of the device is acceptable, despite the presence of dead material due to vessels and support structure. Our approach involves the construction, by a team of physicists and engineers, of one three dimensional model of the LAC system, built as a hierarchy of components and structures, from which we directly perform interferences checks, mechanical, thermal and magnetic analyses, particle tracking, hermeticity evaluation, physics simulation and assembly. This study, begun in February 1989 as part of the SSC generic detector R and D program, was immediately preceded by a workshop at which engineering details of existing and planned LAC systems were thoroughly examined. We describe below the status of our work, beginning with short descriptions of the tools used, the study requirements and LAC configuration baseline. We then detail the LAC design as it presently stands, including assembly considerations, and conclude with a quantitative assessment of the LAC hermeticity. 19 refs., 12 figs

  4. Study of hadrons energy resolution in a liquid argon calorimeter for the H1 experiment and study of supersymmetric particles detection at Hera

    International Nuclear Information System (INIS)

    Tests of liquid Argon calorimeters have been carried out at CERN in 1986 and 1987 in order to study the properties of the forthcoming H1 detector calorimeter installed at the HERA collider. In the first part of this work, from data analysis, several weighting methods of the measured charge for hadronic showers are proposed and discussed. These weighting methods allow to correct the non compensation of liquid Argon calorimeters and so to optimize the hadrons energy resolution. The problem of electrons and pions identification is also met. In the second part, selectron and squark production is considered in the electrons protons collisions of HERA. Signal extraction from standard background is studied with the help of a simulation of supersymmetric and deep inelastic scattering processes as well as a rough simulation of the H1 detector

  5. Experimental and Numerical Investigation of Capillary Driven Free Surface Oscillations of Liquid Argon Under Non-Isothermal Conditions

    Science.gov (United States)

    Kulev, Nikolai; Dreyer, Michael E.

    Knowledge of dynamic behaviour of cryogenic fluids under microgravity is of key importance for the management of cryogenic propellants in space vehicles. In this work we present experimental and numerical investigations of the capillary driven free surface oscillations of liquid argon (Tsat = 87.3K @ 1013 hPa) under non-isothermal boundary conditions. Such oscillations take place during the reorientation of the equilibrium position of the free surface upon step reduction of gravity. The aim was to investigate the impact on the reorientation when the main capillary flow is superimposed in the vicinity of the contact line by a flow, induced by thermal effects due to heat flux from the vessel's hot wall towards the cold cryogenic liquid. The experiments were performed at the Bremen Drop Tower. Axial wall temperature gradients of averaged 0.15 K/mm -1.93 K/mm towards the free surface were implemented. A general dependence of the system behavior on the value of these gradients was observed. Thus the characteristics of the free surface oscillations vary accordingly. The aperiodic movement of the apparent contact line changes to a periodic one, accompanied by a distinctive change in the vapor pressure increase -hinting to a peak evaporation on the receding contact line. Nucleation boiling in the highest range of the axial wall temperature gradients, indicating the formation of thermal wall boundary layers, was also observed. The individual or combined action of the physical mechanisms of Marangoni convection, vapor recoil and evaporation/condensation are to be expected behind the observation. Numerical simulations of the drop tower experiments utilizing the VOF method were exploited in search for the explanation. Simulation results and comparison to the experiment are also presented.

  6. VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

    OpenAIRE

    Francini, R.; Montereali, R. M.; Nichelatti, E.; Vincenti, M. A.; Canci, N.; Segreto, E.; F. Cavanna; Di Pompeo, F.; Carbonara, F.; Fiorillo, G.; Perfetto, F.

    2013-01-01

    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...

  7. Cryogenic THGEM–GPM for the readout of scintillation light from liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wenqing; Fu, Yidong [Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Beijing 100084 (China); Li, Yulan, E-mail: yulanli@mail.tsinghua.edu.cn [Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Beijing 100084 (China); Li, Jin [Institute of High Energy Physics Chinese Academy of Sciences, Beijing 100084 (China); Li, Yuanjing; Yue, Qian [Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Beijing 100084 (China)

    2015-02-21

    A GPM (Gaseous Photo Multiplier) based on GEMs (Gas Electron Multipliers) and THGEMs (Thick Gas Electron Multipliers) is a promising detector for VUV (Vacuum Ultra Violet) photon readouts in rare event experiments which use cryogenic two-phase detectors with detection media of Ar and Xe. A GPM based on THGEM made of PTFE (herein named PTFE-THGEM) was developed inspired by the wide use of PTFE (polytetrafluoroethene) boards as low radioactive background PCB in rare event experiments. The efficiencies of the THGEM, a CsI photocathode, and finally a GPM are presented here. At low temperature (113 K) and 1.1 atm, the quantum efficiency of the GPM for VUV photons from liquid Ar in a two-phase detector is estimated to be 8.1% and the low threshold of the detector system for initial electrons prior to multiplication is 12 using 5 N purity Ar (0.99999)

  8. Cryogenic THGEM–GPM for the readout of scintillation light from liquid argon

    International Nuclear Information System (INIS)

    A GPM (Gaseous Photo Multiplier) based on GEMs (Gas Electron Multipliers) and THGEMs (Thick Gas Electron Multipliers) is a promising detector for VUV (Vacuum Ultra Violet) photon readouts in rare event experiments which use cryogenic two-phase detectors with detection media of Ar and Xe. A GPM based on THGEM made of PTFE (herein named PTFE-THGEM) was developed inspired by the wide use of PTFE (polytetrafluoroethene) boards as low radioactive background PCB in rare event experiments. The efficiencies of the THGEM, a CsI photocathode, and finally a GPM are presented here. At low temperature (113 K) and 1.1 atm, the quantum efficiency of the GPM for VUV photons from liquid Ar in a two-phase detector is estimated to be 8.1% and the low threshold of the detector system for initial electrons prior to multiplication is 12 using 5 N purity Ar (0.99999)

  9. Development and Construction of Large Size Signal Electrodes for the ATLAS Electromagnetic Calorimeter

    CERN Document Server

    Aubert, B; Colas, Jacques; Girard, C; Jérémie, A; Jézéquel, S; Lesueur, J; Sauvage, G; Lissauer, D; Makowiecki, D S; Radeka, V; Rescia, S; Wolniewicz, K; Belymam, A; Hoummada, A; Cherif, A; Chevalley, J L; Hervás, L; Marin, C P; Fassnacht, P; Szeless, Balázs; Collot, J; Gallin-Martel, M L; Hostachy, J Y; Martin, P; Leltchouk, M; Seman, M; Dargent, P; Djama, F; Monnier, E; Olivier, C; Tisserant, S; Battistoni, G; Carminati, L; Cavalli, D; Costa, G; Delmastro, M; Fanti, M; Mandelli, L; Mazzanti, M; Perini, L; Tartarelli, F; Augé, E; Bonivento, W; Fournier, D; Puzo, P; Serin, L; de La Taille, C; Astesan, F; Canton, B; Imbault, D; Lacour, D; Rossel, F; Schwemling, P

    2005-01-01

    We describe the electric circuits (electrodes) which polarize and read out the Lead-Liquid Argon electromagnetic calorimeter for the ATLAS detector. The paper covers design and material choices of the circuits as well as their production in industry. We also show how the electrodes integrate into the calorimeter and conclude with results from groups of electrodes making up calorimeter modules.

  10. An ATLAS inner detector end-cap is placed in its cryostat

    CERN Multimedia

    2007-01-01

    The instrumentation housed inside the inner end-cap must be kept cool to avoid thermal noise. This cooling is achieved on ATLAS by placing the end-cap inside a liquid argon cryostat. The end-cap measures particles that are produced close to the direction of the beam pipe and would otherwise be missed.

  11. ATLAS event at 900 GeV - 6 May 2015 - Run 264034 lb 659 event 11526514

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Display of a proton-proton collision event recorded by ATLAS on 6 May 2015, at 900 GeV collision energy. Tracks reconstructed from hits in the inner tracking detector are shown as orange arcs curving in the solenoidal magnetic field. The green and yellow bars indicate energy deposits in the Liquid Argon and Scintillating Tile calorimeters respectively.

  12. ATLAS event at 13 TeV - 20 May 2015 - Run 265532 Evt 3280065

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Display of a proton-proton collision event recorded by ATLAS on 20 May 2015, at 13 TeV collision energy. Tracks are reconstructed from hits in the outer parts of the inner tracking detector which were switched on at the time. The green and red bars indicate energy deposits in the Liquid Argon and Scintillating Tile calorimeters respectively.

  13. Neutron scattering studies of density fluctuations in liquid argon and neon

    International Nuclear Information System (INIS)

    Coherent dynamic structure factors S(k,ω) obtained by means of thermal neutron inelastic scattering are presented. The experiments were performed on liquid 36Ar at four densities along the 120-K isotherm covering a range of wave numbers k from 4.2 to 39.0 nm-1. The neutron time-of-flight spectra are corrected for all known experimental effects with an improved data-reduction system. Special attention is paid to corrections for multiple scattering, duty-cycle overlap, and instrumental resolution. The importance of various correction steps is shown. The reliability of the corrected data is assessed by means of two independent consistency checks, viz., the detailed-balance condition and the first frequency moment of S(k,ω). The S(k,ω) data are presented both as a function of k at fixed ω and as a function of ω at fixed k. The peak height and full width at half maximum of S(k,ω) at fixed k are shown for all densities together with the small-k (hydrodynamic) and large-k (free-gas) asymptotes. The frequency moments of S(k,ω), evaluated up to the fourth moment, are consistent with results from computer simulations and from theoretical calculations. The longitudinal current correlation function Cl(k,ω), derived from the experimental S(k,ω), is examined and both its peak position (yielding the dispersion curve for longitudinal current fluctuations) and its peak height (a measure of the life time of the fluctuations) are discussed. (Auth.)

  14. ATLAS Solenoid Integration

    CERN Multimedia

    Ruber, R

    Last month the central solenoid was installed in the barrel cryostat, which it shares with the liquid argon calorimeter. Figure 1: Some members of the solenoid and liquid argon teams proudly pose in front of the barrel cryosat, complete with detector and magnet. Some two years ago the central solenoid arrived at CERN after being manufactured and tested in Japan. It was kept in storage until last October when it was finally moved to the barrel cryostat integration area. Here a position survey of the solenoid (with respect to the cryostat's inner warm vessel) was performed. Figure 2: The alignment survey by Dirk Mergelkuhl and Aude Wiart. (EST-SU) At the start of the New Year the solenoid was moved to the cryostat insertion stand. Figure 3: The solenoid on the insertion stand, with Akira Yamamoto the solenoid designer and project leader. Figure 4: Taka Kondo, ATLAS Japan spokesperson, and Shoichi Mizumaki, Toshiba project engineer for the ATLAS solenoid, celebrate the insertion. Aft...

  15. ATLAS solenoid operates underground

    CERN Multimedia

    2006-01-01

    A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the Central Solenoid. Teams monitoring the cooling and powering of the ATLAS solenoid in the control room. The solenoid was cooled down to 4.5 K from 17 to 23 May. The first current was established the same evening that the solenoid became cold and superconductive. 'This makes the ATLAS Central Solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas!', said Takahiko Kondo, professor at KEK. Though the current was limited to 1 kA, the cool-down and powering of the solenoid was a major milestone for all of the control, cryogenic, power and vacuum systems-a milestone reached by the hard work and many long evenings invested by various teams from ATLAS, all of CERN's departments and several large and small companies. Since the Central Solenoid and the barrel liquid argon (LAr) calorimeter share the same cryostat vacuum vessel, this achievement was only possible in perfe...

  16. ATLAS

    CERN Multimedia

    Akhnazarov, V; Canepa, A; Bremer, J; Burckhart, H; Cattai, A; Voss, R; Hervas, L; Kaplon, J; Nessi, M; Werner, P; Ten kate, H; Tyrvainen, H; Vandelli, W; Krasznahorkay, A; Gray, H; Alvarez gonzalez, B; Eifert, T F; Rolando, G; Oide, H; Barak, L; Glatzer, J; Backhaus, M; Schaefer, D M; Maciejewski, J P; Milic, A; Jin, S; Von torne, E; Limbach, C; Medinnis, M J; Gregor, I; Levonian, S; Schmitt, S; Waananen, A; Monnier, E; Muanza, S G; Pralavorio, P; Talby, M; Tiouchichine, E; Tocut, V M; Rybkin, G; Wang, S; Lacour, D; Laforge, B; Ocariz, J H; Bertoli, W; Malaescu, B; Sbarra, C; Yamamoto, A; Sasaki, O; Koriki, T; Hara, K; Da silva gomes, A; Carvalho maneira, J; Marcalo da palma, A; Chekulaev, S; Tikhomirov, V; Snesarev, A; Buzykaev, A; Maslennikov, A; Peleganchuk, S; Sukharev, A; Kaplan, B E; Swiatlowski, M J; Nef, P D; Schnoor, U; Oakham, G F; Ueno, R; Orr, R S; Abouzeid, O; Haug, S; Peng, H; Kus, V; Vitek, M; Temming, K K; Dang, N P; Meier, K; Schultz-coulon, H; Geisler, M P; Sander, H; 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Vasilyeva, L; Speransky, M; Smirnov, S; Antonov, A; Bulekov, O; Tikhonov, Y; Sargsyan, L; Vardanyan, G; Budick, B; Kocian, M L; Luitz, S; Young, C C; Grenier, P J; Kelsey, M; Black, J E; Kneringer, E; Jussel, P; Horton, A J; Beaudry, J; Chandra, A; Ereditato, A; Topfel, C M; Mathieu, R; Bucci, F; Muenstermann, D; White, R M; He, M; Urban, J; Straka, M; Vrba, V; Schumacher, M; Parzefall, U; Mahboubi, K; Sommer, P O; Koepke, L H; Bethke, S; Moser, H; Wiesmann, M; Walkowiak, W A; Fleck, I J; Martinez-perez, M; Sanchez sanchez, C A; Jorgensen roca, S; Accion garcia, E; Sainz ruiz, C A; Valls ferrer, J A; Amoros vicente, G; Vives torrescasana, R; Ouraou, A; Formica, A; Hassani, S; Watson, M F; Cottin buracchio, G F; Bussey, P J; Saxon, D; Ferrando, J E; Collins-tooth, C L; Hall, D C; Cuhadar donszelmann, T; Dawson, I; Duxfield, R; Argyropoulos, T; Brodet, E; Livneh, R; Shougaev, K; Reinherz, E I; Guttman, N; Beretta, M M; Vilucchi, E; Aloisio, A; Patricelli, S; Caprio, M; Cevenini, F; De vecchi, C; Livan, M; Rimoldi, A; Vercesi, V; Ayad, R; Mastroberardino, A; Ciapetti, G; Luminari, L; Rescigno, M; Santonico, R; Salamon, A; Del papa, C; Kurashige, H; Homma, Y; Tomoto, M; Horii, Y; Sugaya, Y; Hanagaki, K; Bobbink, G; Kluit, P M; Koffeman, E N; Van eijk, B; Lee, H; Eigen, G; Dorholt, O; Strandlie, A; Strzempek, P B; Dita, S; Stoicea, G; Chitan, A; Leven, S S; Moa, T; Brenner, R; Ekelof, T J C; Olshevskiy, A; Roumiantsev, V; Chlachidze, G; Zimine, N; Gusakov, Y; Grigalashvili, N; Mineev, M; Potrap, I; Barashkou, A; Shoukavy, D; Shaykhatdenov, B; Pikelner, A; Gladilin, L; Ammosov, V; Abramov, A; Arik, M; Sahinsoy, M; Uysal, Z; Azizi, K; Hotinli, S C; Zhou, S; Berger, E; Blair, R; Underwood, D G; Einsweiler, K; Garcia-sciveres, M A; Siegrist, J L; Kipnis, I; Dahl, O; Holland, S; Barbaro galtieri, A; Smith, P T; Parua, N; Franklin, M; Mercurio, K M; Tong, B; Pod, E; Cole, S G; Hopkins, W H; Guest, D H; Severini, H; Marsicano, J J; Abbott, B K; Wang, Q; Lissauer, D; Ma, H; Takai, H; Rajagopalan, S; Protopopescu, S D; Snyder, S S; Undrus, A; Popescu, R N; Begel, M A; Blocker, C A; Amelung, C; Mandic, I; Macek, B; Tucker, B H; Citterio, M; Troncon, C; Orestano, D; Taccini, C; Romeo, G L; Dova, M T; Taylor, G N; Gesualdi manhaes, A; Mcpherson, R A; Sobie, R; Taylor, R P; Dolezal, Z; Kodys, P; Slovak, R; Sopko, B; Vacek, V; Sanders, M P; Hertenberger, R; Meineck, C; Becks, K; Kind, P; Sandhoff, M; Cantero garcia, J; De la torre perez, H; Castillo gimenez, V; Ros, E; Hernandez jimenez, Y; Chadelas, R; Santoni, C; Washbrook, A J; O'brien, B J; Wynne, B M; Mehta, A; Vossebeld, J H; Landon, M; Teixeira dias castanheira, M; Cerrito, L; Keates, J R; Fassouliotis, D; Chardalas, M; Manousos, A; Grachev, V; Seliverstov, D; Sedykh, E; Cakir, O; Ciftci, R; Edson, W; Prell, S A; Rosati, M; Stroman, T; Jiang, H; Neal, H A; Li, X; Gan, K K; Smith, D S; Kruse, M C; Ko, B R; Leung fook cheong, A M; Cole, B; Angerami, A R; Greene, Z S; Kroll, J I; Van berg, R P; Forbush, D A; Lubatti, H; Raisher, J; Shupe, M A; Wolin, S; Oshita, H; Gaudio, G; Das, R; Konig, A C; Croft, V A; Harvey, A; Maaroufi, F; Melo, I; Greenwood jr, Z D; Shabalina, E; Mchedlidze, G; Drechsler, E; Rieger, J K; Blackston, M; Colombo, T

    2002-01-01

    % ATLAS \\\\ \\\\ ATLAS is a general-purpose experiment for recording proton-proton collisions at LHC. The ATLAS collaboration consists of 144 participating institutions (June 1998) with more than 1750~physicists and engineers (700 from non-Member States). The detector design has been optimized to cover the largest possible range of LHC physics: searches for Higgs bosons and alternative schemes for the spontaneous symmetry-breaking mechanism; searches for supersymmetric particles, new gauge bosons, leptoquarks, and quark and lepton compositeness indicating extensions to the Standard Model and new physics beyond it; studies of the origin of CP violation via high-precision measurements of CP-violating B-decays; high-precision measurements of the third quark family such as the top-quark mass and decay properties, rare decays of B-hadrons, spectroscopy of rare B-hadrons, and $ B ^0 _{s} $-mixing. \\\\ \\\\The ATLAS dectector, shown in the Figure includes an inner tracking detector inside a 2~T~solenoid providing an axial...

  17. A large liquid argon time projection chamber for long-baseline, off-axis neutrino oscillation physics with the NuMI beam

    International Nuclear Information System (INIS)

    Results from neutrino oscillation experiments in the last ten years have revolutionized the field of neutrino physics. While the overall oscillation picture for three neutrinos is now well established and precision measurements of the oscillation parameters are underway, crucial issues remain. In particular, the hierarchy of the neutrino masses, the structure of the neutrino mixing matrix, and, above all, CP violation in the neutrino sector are the primary experimental challenges in upcoming years. A program that utilizes the newly commissioned NuMI neutrino beamline, and its planned upgrades, together with a high-performance, large-mass detector will be in an excellent position to provide decisive answers to these key neutrino physics questions. A Liquid Argon time projection chamber (LArTPC), which combines fine-grained tracking, total absorption calorimetry, and scalability, is well matched for this physics program. The few-millimeter-scale spatial granularity of a LArTPC combined with dE/dx measurements make it a powerful detector for neutrino oscillation physics. Scans of simulated event samples, both directed and blind, have shown that electron identification in νe charged current interactions can be maintained at an efficiency of 80%. Backgrounds for νe appearance searches from neutral current events with a π0 are reduced well below the ∼ 0.5-1.0% νe contamination of the νμ beam. While the ICARUS collaboration has pioneered this technology and shown its feasibility with successful operation of the T600 (600-ton) LArTPC, a detector for off-axis, long-baseline neutrino physics must be many times more massive to compensate for the low event rates. We have a baseline concept based on the ICARUS wire plane structure and commercial methods of argon purification and housed in an industrial liquefied-natural-gas tank. Fifteen to fifty kton liquid argon capacity tanks have been considered. A very preliminary cost estimate for a 50-kton detector is $100M

  18. One of the first heavy-ion collisions with stable beams recorded by ATLAS in November 2015.

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    One of the first heavy-ion collisions with stable beams recorded by ATLAS in November 2015. Tracks reconstructed from hits in the inner tracking detector are shown as orange arcs curving in the solenoidal magnetic field. The green and yellow bars indicate energy deposits in the Liquid Argon and Scintillating Tile calorimeters respectively.

  19. Analog pipeline readout for ATLAS calorimetry

    International Nuclear Information System (INIS)

    This paper presents the design and prototype testing of an analog pipeline readout module suitable for readout of the LAr calorimetry at the large hadron collider. The design has been driven by the readout requirements of the ATLAS electromagnetic liquid argon calorimeter and the ATLAS trigger design parameters. The results indicate that an analog pipeline readout system meeting the ATLAS requirements can be built using our modules. The SCA-chip employed has resolution approaching 13-bits (using the full range of the SCA) and can achieve a 16-bit dynamic range using a dual-range scheme. The module is based on switched capacitor array chips. A brief description of the design of the pipeline controller development, that will enable the SCA readout system to run as a deadtimeless analog RAM, is also given. (orig.)

  20. Upgrades to the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Plucinski, P; The ATLAS collaboration; Qian, W

    2014-01-01

    ABSTRACT: 2015 the Large Hadron Collider will run with increased center-of-mass energy and luminosity. To maintain trigger efficiency against increased pileup rates, event topology information will be added to the ATLAS Level-1 real time data path and processed by a new Topology Processor (L1Topo). In phase-I, a new digital readout for the Liquid Argon calorimeters will provide finer granularity and depth segmentation in the electromagnetic layer to new Level-1 feature extractors (FEX) for improved EM, tau and jet identification. We present the topology and phase-I trigger upgrades to the ATLAS Level-1 trigger.

  1. Upgrades to the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Plucinski, P; The ATLAS collaboration; Qian, W

    2013-01-01

    In 2015 the Large Hadron Collider will run with increased center-of-mass energy and luminosity. To maintain trigger efficiency against increased pileup rates, event topology information will be added to the ATLAS Level-1 real time data path and processed by a new Topology Processor (L1Topo). In phase-I, a new digital readout for the Liquid Argon calorimeters will provide finer granularity and depth segmentation in the electromagnetic layer to new Level-1 feature extractors (FEX) for improved EM, tau and jet identification. We present the topology and phase-I trigger upgrades to the ATLAS Level-1 trigger.

  2. Test beam results of the ATLAS electromagnetic calorimeter prototype modules

    CERN Document Server

    Maslennikov, A L

    2002-01-01

    The pre-series modules of the future ATLAS liquid argon electromagnetic calorimeter (the LHC project) have been tested in 1999-2000 with electron beams at CERN SPS. Detailed results of these tests are presented, including the performance of ATLAS-like electronics. Energy resolution of better than 9.5%/ root E (barrel) and 10.5-12.5%/ root E (end-cap) is obtained. Angular resolution measured ( asymptotically equal to 50 mrad/ root E, end-cap) also fits to physics requirements.

  3. The upgrade of the ATLAS first-level calorimeter trigger

    Science.gov (United States)

    Yamamoto, Shimpei

    2016-07-01

    The first-level calorimeter trigger (L1Calo) had operated successfully through the first data taking phase of the ATLAS experiment at the CERN Large Hadron Collider. Towards forthcoming LHC runs, a series of upgrades is planned for L1Calo to face new challenges posed by the upcoming increases of the beam energy and the luminosity. This paper reviews the ATLAS L1Calo trigger upgrade project that introduces new architectures for the liquid-argon calorimeter trigger readout and the L1Calo trigger processing system.

  4. Study of neutron induced outgassing from tungsten alloy for ATLAS FCAL

    CERN Document Server

    Leroy, C; Cheplakov, A P; Golikov, V; Golubyh, S M; Kulagin, E; Kukhtin, V; Luschikov, V

    1999-01-01

    The use of sintered tungsten alloy slugs as absorber in the ATLAS Forward Calorimeter (FCAL) raised concern that it could possibly poison the liquid argon during the detector operation in the hard radiation environment expected at LHC. A vacuum container filled with tungsten slugs was exposed to the fast neutron fluence of 1.5$\\cdot$10$^{16}$~n~cm$^{-2}$ at the IBR-30 reactor of JINR, Dubna. The residual gas pressure was analysed. The study was completed by mass spectrometer measurements. An upper limit value of 0.1~ppm was determined for the pollution of liquid argon in FCAL due to outgassing from tungsten slugs under irradiation.

  5. Properties of a lead and copper calorimeter in liquid argon for measuring high energy jets with special regard to reducing shower fluctuations

    International Nuclear Information System (INIS)

    In the course of the development of the liquid argon calorimeter of the H1 experiment, measurements have been performed using electron and pion beams in the energy range of 30 to 230 GeV. The test calorimeter consisted of an electromagnetic section (Pb absorber) corresponding to 26 X0 (1.1 λ) and a hadronic section (Cu absorber) corresponding to 6.1 λ. In analogy to the situation in the H1 experiment, an iron streamer tube calorimeter corresponding to 4.3 λ was placed behind the test setup. The properties of electromagnetic and hadronic showers in the liquid argon calorimeter are discussed and compared with Monte Carlo predictions (GHEISHA, version 8). Special consideration is given to reducing the fluctuations of the π0-energy in hadronic showers on an 'event by event' basis. A nonlinear calibration function parametrized with the energy of the primary pion leads to the ratio of the response of electrons to that of pions being equal to one and therefore to a significantly improved energy resolution for pions. The energy resolution is determined and the spatial resolution for incident pions is measured. (orig./HP)

  6. Single-walled nanohorns and other nanocarbons generated by submerged arc discharge between carbon electrodes in liquid argon and other media

    International Nuclear Information System (INIS)

    Arc discharge between two graphite electrodes submerged in different liquid media yields various dimensional nanocarbon structures such as 1D carbon nanotubes and 2D graphene. Single-walled carbon nanohorns (SWNHs) prepared by submerged arc discharge in liquid nitrogen medium are found to have nitrogen impurities. Here, we report the structure and properties of pure and nitrogen-doped SWNHs obtained by submerged arc discharge in a liquid argon medium. The absence of an XPS N 1s signal, which is present in nanohorns obtained in liquid nitrogen, indicate that the nanohorns are free from nitrogen impurities. Raman spectra show a strong defect-induced D band and current–voltage characteristics show a slight nonlinear behavior. N2 adsorption of pure SWNHs shows type-IV isotherms with a surface area of 300 m2 g−1. Adsorption of CO2 and H2 in pure SWNHs has also been measured. Arc discharge in other liquid media such as water, ethanol, dimethylformamide (DMF), n-methyl pyrrolidone (NMP), formamide, benzene, heptane and acetone yields different nanocarbon structures including multi-walled carbon nanotubes (MWNTs), few-layer graphene, carbon onions and carbon nanoparticles. (papers)

  7. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    International Nuclear Information System (INIS)

    Po analysis show the high level of radiopurity reached in Double Chooz. In addition, with the BiPo analysis the α-quenching factors for the Target and the GammaCatcher liquids have been determined, respectively, to 9.94±0.04 and 13.69±0.02 at 7.7 MeV, and 9.05±0.01 and 14.3±0.1 at 8.8 MeV. The former values show a good agreement with the values obtained in a dedicated laboratory measurement. The time stability of the peak position of the 214Po α-peak could be proven, too, showing a stable detector performance at low visible energies. The direct search for Dark Matter can, amongst others, be performed with liquid rare gas detectors, which make use of the scintillation light. However, a good background discrimination is needed. Studies on the wavelength- and time-resolved scintillation properties of liquid argon have therefore been carried out with high resolution and best statistics. The results obtained for different ion beams show that particle discrimination is not feasible in any realistic experiment by means of the wavelength-resolved scintillation light only, but the time structure of the emitted light provides a good handle to distinguish between different incident particles. For heavy ions (sulfur) a ratio of the fast to the slow scintillation component of (1.6 ± 0.6) is found, while lighter particles (protons) exhibit a ratio of (0.25 ± 0.05). The outcome of the present studies shows that this ratio can also be used in wavelength-integrating measurements which have a comparable detection efficiency for wavelengths below and above ∝170 nm. The present results demonstrate that for a number of 90 detected photons the singlet-to-triplet distributions obtained for sulfur ions and protons as exciting particles cease to overlap. In a Dark Matter experiment, if all photons produced can be detected, this corresponds to a discrimination threshold of only 2.25 keV.

  8. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Martin Alexander

    2012-11-27

    }(g)/(g)). Both gamma spectroscopy measurements and the BiPo analysis show the high level of radiopurity reached in Double Chooz. In addition, with the BiPo analysis the {alpha}-quenching factors for the Target and the GammaCatcher liquids have been determined, respectively, to 9.94{+-}0.04 and 13.69{+-}0.02 at 7.7 MeV, and 9.05{+-}0.01 and 14.3{+-}0.1 at 8.8 MeV. The former values show a good agreement with the values obtained in a dedicated laboratory measurement. The time stability of the peak position of the {sup 214}Po {alpha}-peak could be proven, too, showing a stable detector performance at low visible energies. The direct search for Dark Matter can, amongst others, be performed with liquid rare gas detectors, which make use of the scintillation light. However, a good background discrimination is needed. Studies on the wavelength- and time-resolved scintillation properties of liquid argon have therefore been carried out with high resolution and best statistics. The results obtained for different ion beams show that particle discrimination is not feasible in any realistic experiment by means of the wavelength-resolved scintillation light only, but the time structure of the emitted light provides a good handle to distinguish between different incident particles. For heavy ions (sulfur) a ratio of the fast to the slow scintillation component of (1.6 {+-} 0.6) is found, while lighter particles (protons) exhibit a ratio of (0.25 {+-} 0.05). The outcome of the present studies shows that this ratio can also be used in wavelength-integrating measurements which have a comparable detection efficiency for wavelengths below and above {proportional_to}170 nm. The present results demonstrate that for a number of 90 detected photons the singlet-to-triplet distributions obtained for sulfur ions and protons as exciting particles cease to overlap. In a Dark Matter experiment, if all photons produced can be detected, this corresponds to a discrimination threshold of only 2.25 keV.

  9. VUV-VIS optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

    CERN Document Server

    Francini, R; Nichelatti, E; Vincenti, M A; Canci, N; Segreto, E; Cavanna, F; Di Pompeo, F; Carbonara, F; Fiorillo, G; Perfetto, F

    2013-01-01

    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) are fully understood. Characterization of the optical system requires specific, sometimes sophisticated optical methodologies. In this paper the main features of TPB coatings on different, commonly used substrates is reported, as a result of two independent campaigns of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshap...

  10. Muon-induced background to proton decay in the p→K+ν decay channel with large underground liquid argon TPC detectors

    Directory of Open Access Journals (Sweden)

    J. Klinger

    2015-06-01

    Full Text Available Large liquid argon TPC detector programs such as LBNE and LAGUNA-LBNO will be able to make measurements of the proton lifetime which will outperform Cherenkov detectors in the proton decay channel p→K+ν. At the large depths which are proposed for such experiments, a non-negligible source of isolated charged kaons may be produced in the showers of cosmogenic muons. We present an estimate of the cosmogenic muon background to proton decay in the p→K+ν channel. The simulation of muon transport to a depth of 4 km w.e. is performed in the MUSIC framework and the subsequent propagation of muons and secondary particles in the vicinity of a cylindrical 20 kt LAr target is performed using Geant4. An exposure time of 100 years is considered, with a rate of <0.0012 events/kt/year at 90% CL predicted from our simulations.

  11. Muon-induced background to proton decay in the p →K+ ν decay channel with large underground liquid argon TPC detectors

    Science.gov (United States)

    Klinger, J.; Kudryavtsev, V. A.; Richardson, M.; Spooner, N. J. C.

    2015-06-01

    Large liquid argon TPC detector programs such as LBNE and LAGUNA-LBNO will be able to make measurements of the proton lifetime which will outperform Cherenkov detectors in the proton decay channel p →K+ ν. At the large depths which are proposed for such experiments, a non-negligible source of isolated charged kaons may be produced in the showers of cosmogenic muons. We present an estimate of the cosmogenic muon background to proton decay in the p →K+ ν channel. The simulation of muon transport to a depth of 4 km w.e. is performed in the MUSIC framework and the subsequent propagation of muons and secondary particles in the vicinity of a cylindrical 20 kt LAr target is performed using GEANT4. An exposure time of 100 years is considered, with a rate of <0.0012 events/kt/year at 90% CL predicted from our simulations.

  12. Spring comes for ATLAS

    CERN Multimedia

    Butin, F.

    2004-01-01

    (First published in the CERN weekly bulletin 24/2004, 7 June 2004.) A short while ago the ATLAS cavern underwent a spring clean, marking the end of the installation of the detector's support structures and the cavern's general infrastructure. The list of infrastructure to be installed in the ATLAS cavern from September 2003 was long: a thousand tonnes of mechanical structures spread over 13 storeys, two lifts, two 65-tonne overhead travelling cranes 25 metres above cavern floor, with a telescopic boom and cradle to access the remaining 10 metres of the cavern, a ventilation system for the 55 000 cubic metre cavern, a drainage system, a standard sprinkler system and an innovative foam fire-extinguishing system, as well as the external cryogenic system for the superconducting magnets and the liquid argon calorimeters (comprising, amongst other things, two helium refrigeration units, a nitrogen refrigeration unit and 5 km of piping for gaseous or liquid helium and nitrogen), not to mention the handling eq...

  13. Simulation of Liquid Argon Flow along a Nanochannel: Effect of Applied Force%液氩沿纳米级微通道流动的模拟:外力的影响

    Institute of Scientific and Technical Information of China (English)

    YIN Chun-Yang; El-Harbawi Mohanad

    2009-01-01

    Liquid argon flow along a nanochannel is studied using molecular dynamics (MD) simulation in this work. Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) is used as the MD simulator. The effects of reduced forces at 0.5, 1.0 and 2.0 on argon flow on system energy in the form of system potential energy, pressure and velocity profile are described. Output in the form of three-dimensional visualization of the system at steady-state condition using Visual Molecular Dynamics (VMD) is provided to describe the dynamics of the argon atoms. The equilibrium state is reached after 16000 time steps. The effects on system energy, pressure and velocity profile due to reduced force of 2.0 (F2) are clearly distinguishable from the other two lower forces where sufficiently high net force along the direction of the nanochannel for F2 renders the attractive and repulsive forces between the argon atoms virtually non-existent. A reduced force of 0.5 (F0.5) provides liquid argon flow that approaches Poiseuille (laminar) flow as clearly shown by the n-shaped average velocity profile. The extension of the present MD model to a more practical application affords scientists and engineers a good option for simulation of other nanofluidic dynamics processes.

  14. Calibration boards for the ATLAS LAr calorimeters

    International Nuclear Information System (INIS)

    In order to calibrate the ATLAS Liquid Argon (LAr) calorimeters to an accuracy better than 1%, over 16 bit dynamic range, chips have been designed in DMILL technology. The design and performance of a 16 bit DAC, a static low offset operational amplifier and a digital chip to control the calibration boards are presented. A 8 channels board using these chips has also been realised and carefully measured as this module will be replicated 16 times to design the final 128 channels calibration board. (authors)

  15. ATLAS calorimeters energy calibration for jets

    International Nuclear Information System (INIS)

    The calibration of ATLAS barrel calorimeters (including pre shower system, electromagnetic Liquid Argon calorimeter and scintillating hadron tile calorimeter) was done by standard calibration and weighting technique approaches. The standard calibration gives the bad linearity for hadron non compensated calorimeter. The calibration with weighting technique, in comparison with standard calibration, restores linearity and improves energy resolution up to (σ/E)2 = (38.6%/√E)2 + (1.5%)2 for η 0.6. 6 refs., 4 figs., 1 tab

  16. ATLAS: last few metresfor the Calorimeter

    CERN Multimedia

    2005-01-01

    On Friday 4th November, the ATLAS Barrel Calorimeter was moved from its assembly point at the side of the ATLAS cavern to the centre of the toroidal magnet system. The detector was finally aligned, to the precision of within a millimetre, on Wednesday 9th November. The ATLAS installation team, led by Tommi Nyman, after having positioned the Barrel Calorimeter in its final location in the ATLAS experimental cavern UX15. The Barrel Calorimeter which will absorb and measure the energy of photons, electrons and hadrons at the core of the ATLAS detector is 8.6 meters in diameter, 6.8 meters long, and weighs over 1600 Tonnes. It consists of two concentric cylindrical detector elements. The innermost comprises aluminium pressure vessels containing the liquid argon electromagnetic calorimeter and the solenoid magnet. The outermost is an assembly of 64 hadron tile calorimeter sectors. Assembled 18 meters away from its final position, the Barrel Calorimeter was relocated with the help of a railway, which allows the ...

  17. ATLAS event at 13 TeV - First stable beam, 3 June 2015 - run: 266904

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Display of proton-proton collision events recorded by ATLAS on 3 June 2015, with the first LHC stable beams at a collision energy of 13 TeV. Tracks reconstructed from hits in the inner tracking detector are shown as arcs curving in the solenoidal magnetic field. The green and yellow bars indicate energy deposits in the liquid argon and scintillating-tile calorimeters.

  18. Performance of a proximity cryogenic system for the ATLAS central solenoid magnet

    CERN Document Server

    Doi, Y; Makida, Y; Kondo, Y; Kawai, M; Aoki, K; Haruyama, T; Kondo, T; Mizumaki, S; Wachi, Y; Mine, S; Haug, F; Delruelle, N; Passardi, Giorgio; ten Kate, H H J

    2002-01-01

    The ATLAS central solenoid magnet has been designed and constructed as a collaborative work between KEK and CERN for the ATLAS experiment in the LHC project The solenoid provides an axial magnetic field of 2 Tesla at the center of the tracking volume of the ATLAS detector. The solenoid is installed in a common cryostat of a liquid-argon calorimeter in order to minimize the mass of the cryostat wall. The coil is cooled indirectly by using two-phase helium flow in a pair of serpentine cooling line. The cryogen is supplied by the ATLAS cryogenic plant, which also supplies helium to the Toroid magnet systems. The proximity cryogenic system for the solenoid has two major components: a control dewar and a valve unit In addition, a programmable logic controller, PLC, was prepared for the automatic operation and solenoid test in Japan. This paper describes the design of the proximity cryogenic system and results of the performance test. (7 refs).

  19. ATLAS Physicist in Space

    CERN Multimedia

    Bengt Lund-Jensen

    2007-01-01

    On December 9, the former ATLAS physicist Christer Fuglesang was launched into space onboard the STS-116 Space Shuttle flight from Kennedy Space Center in Florida. Christer worked on the development of the accordion-type liquid argon calorimeter and SUSY simulations in what eventually became ATLAS until summer 1992 when he became one out of six astronaut trainees with the European Space Agency (ESA). His selection out of a very large number of applicants from all over the ESA member states involved a number of tests in order to choose the most suitable candidates. As ESA astronaut Christer trained with the Russian Soyuz programme in Star City outside of Moscow from 1993 until 1996, when he moved to Houston to train for space shuttle missions with NASA. Christer belonged to the backup crew for the Euromir95 mission. After additional training in Russia, Christer qualified as ‘Soyuz return commander’ in 1998. Christer rerouting cables during his second space walk. (Photo: courtesy NASA) During...

  20. Conceptual design of a large cavern for giant liquid argon charge imaging equipment in Oki-no-shima Island

    International Nuclear Information System (INIS)

    The T2K utilizing J-PARK high intensity started the data accumulation. If beam intensity of J-PARC will become the 1MW class in the future, we will build the cavern under the ground in Oki-no-shima to accommodate the experiment with 100kton liquid Ar TPC. Geologically, the Oki gneiss in the Oki-no-shima eastern side is very stable. The Oki gneiss is the one of the Japanese oldest rocks born about 2 billion years ago and compressive strength of the bedrock is about 80Mpa over. The development of the crack is not seen and has few springs in the underground. We designed large dome cylindrical cavern(the diameter 90m and the height 50m) for storage 100kton liquid Ar, some access tunnel and others connected to a cavern. (author)

  1. Measurement of the ionization yield of nuclear recoils in liquid argon at 80 and 233 keV

    CERN Document Server

    Bondar, A; Dolgov, A; Grishnyaev, E; Polosatkin, S; Shekhtman, L; Shemyakina, E; Sokolov, A

    2014-01-01

    The energy calibration of nuclear recoil detectors is of primary importance to rare-event experiments such as those of direct dark matter search and coherent neutrino-nucleus scattering. In particular, such a calibration is performed by measuring the ionization yield of nuclear recoils in liquid Ar and Xe detection media, using neutron elastic scattering off nuclei. In the present work, the ionization yield for nuclear recoils in liquid Ar has for the first time been measured in the higher energy range, at 80 and 233 keV, using a two-phase Cryogenic Avalanche Detector (CRAD) and DD neutron generator. The ionization yield in liquid Ar at an electric field of 2.3 kV/cm amounted to 7.8+/-1.1 and 9.7+/-1.3 e-/keV at 80 and 233 keV respectively. Neither Jaffe model for nuclear recoil-induced ionization nor that of Thomas-Imel can consistently describe the energy dependence of the ionization yield.

  2. 2001, the ATLAS Cryostat Odyssey

    CERN Multimedia

    2001-01-01

    After a journey of several thousand kilometres, over sea and land, by canal and highway, the cryogenics barrel of the ATLAS electromagnetic calorimeter finally arrived at CERN last week. Installed in Hall 180, the cryogenics barrel of the ATLAS electromagnetic calorimeter will be fitted out to take the central superconducting solenoid and the electromagnetic calorimeter. On Monday 2 July, different French police units and EDF officials were once again keeping careful watch around the hairpin bends of the road twisting down from the Col de la Faucille: a special load weighing 100 tonnes, 7 metres high, 5.8 metres wide and 7.2 metres long was being brought down into the Pays de Gex to the Meyrin site of CERN. This time the destination was the ATLAS experiment. A huge blue tarpaulin cover concealed the cryogenics barrel of the experiment's liquid argon electromagnetic calorimeter. The cryostat consists of a vacuum chamber, a cylinder that is 5.5 metres in diameter, 7 metres long, and a concentric cold chamber ...

  3. Proposal for a Full-Scale Prototype Single-Phase Liquid Argon Time Projection Chamber and Detector Beam Test at CERN

    CERN Document Server

    Kutter, T

    2015-01-01

    The Deep Underground Neutrino Experiment (DUNE) will use a large liquid argon (LAr) detector to measure the CP violating phase, determine the neutrino mass hier- archy and perform precision tests of the three-flavor paradigm in long-baseline neutrino oscillations. The detector will consist of four modules each with a fiducial mass of 10 kt of LAr and due to its unprecedented size will allow sensitive searches for proton decay and the detection and measurement of electron neutrinos from core collapse supernovae [1]. The first 10 kt module will use single-phase LAr detection technique and be itself modular in design. The successful manufacturing, installation and operation of several full-scale detector components in a suitable configuration represents a critical engineering milestone prior to the construction and operation of the first full 10 kt DUNE detector module at the SURF underground site. A charged particle beam test of a prototype detector will provide critical calibration measurements as well as inva...

  4. VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

    Science.gov (United States)

    Francini, R.; Montereali, R. M.; Nichelatti, E.; Vincenti, M. A.; Canci, N.; Segreto, E.; Cavanna, F.; Di Pompeo, F.; Carbonara, F.; Fiorillo, G.; Perfetto, F.

    2013-09-01

    The use of efficient wavelength-shifters from the vacuum-ultraviolet to the photo-sensor'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) are fully understood. Characterization of the optical system requires specific, sometimes sophisticated optical methodologies. In this paper the main features of TPB coatings on different, commonly used substrates is reported, as a result of two independent campaigns of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission.

  5. First Demonstration of Imaging Cosmic Muons in a Two-Phase Liquid Argon TPC using an EMCCD Camera and a THGEM

    CERN Document Server

    Mavrokoridis, K; McCormick, K J; Paudyal, P; Roberts, A; Smith, N A; Touramanis, C

    2015-01-01

    Colossal two-phase Liquid Argon Time Projection Chambers (LAr TPCs) are a proposed option for future long-baseline neutrino experiments. This study illustrates the feasibility of using an EMCCD camera to capture light induced by single cosmic events in a two-phase LAr TPC employing a THGEM. An Andor iXon Ultra 897 EMCCD camera was externally mounted via a borosilicate glass viewport on the Liverpool two-phase LAr TPC. The camera successfully captured the secondary scintillation light produced at the THGEM holes that had been induced by cosmic events. The light collection capability of the camera for various EMCCD gains was assessed. For a THGEM gain of 64 and an EMCCD gain of 1000, clear images were captured with an average signal-to-noise ratio of 6. Preliminary 3D reconstruction of straight cosmic muon tracks has been performed by combining the camera images, PMT signals and THGEM charge data. Reconstructed cosmic muon tracks were used to determine THGEM gain and to calibrate the intensity levels of the EMC...

  6. Neutrino Oscillations With A Next Generation Liquid Argon TPC Detector in Kamioka or Korea Along The J-PARC Neutrino Beam

    CERN Document Server

    Meregaglia, A

    2008-01-01

    The ``baseline setup'' for a possible, beyond T2K, next generation long baseline experiment along the J-PARC neutrino beam produced at Tokai, assumes two very large deep-underground Water Cerenkov imaging detectors of about 300 kton fiducial each, located one in Korea and the other in Kamioka but at the same off-axis angle. In this paper, we consider the physics performance of a similar setup but with a single and smaller, far detector, possibly at shallow depth, composed of a 100 kton next generation liquid Argon Time Projection Chamber. The potential location of the detector could be in the Kamioka area ($L\\sim 295$ km) or on the Eastern Korean coast ($L\\sim 1025$ km), depending on the results of the T2K experiment. In Korea the off-axis angle could be either $2.5^{o} \\sim 3^{o}$ as in SuperKamiokande, or $\\sim 1^{o}$ as to offer pseudo-wide-band beam conditions.

  7. A measurement of the e/π ratio difference between short (250 ns) and long (2.2 μs) integration times with the D0 uranium-liquid argon central calorimeter

    International Nuclear Information System (INIS)

    The difference of the ratios of the high energy electron and pion responses(e/π) in the DO Uranium-liquid Argon central calorimeter is measured using the DO calorimeter trigger readout (short integration time: 250 ns) and precision readout (long integration time: 2.2 μs). This measurement found a 5% difference in the e/π ratio between short and long integration times, with estimated uncertainty of 2.3%

  8. Power distribution for the ATLAS LAr Trigger Digitizer Board

    International Nuclear Information System (INIS)

    The R and D activity for the design of the power distribution section of the ATLAS Liquid Argon (LAr) Calorimeter Trigger Digitizer Board board (LTDB) is presented. Many aspects concerning the radiation hardness and the ability to operate Point-of-load converters also in presence of high magnetic fields are covered. Devices designed by CERN for experiments at LHC have been used and their capability for implementation in the LTDB has been exploited with the aim to have a power distribution section with the required performances

  9. ATLAS 13 TeV Stable Beam Collisions

    CERN Multimedia

    2015-01-01

    Display of a proton-proton collision event recorded by ATLAS on 3 June 2015, with the first LHC stable beams at a collision energy of 13 TeV. Tracks reconstructed from hits in the inner tracking detector are shown as arcs curving in the solenoidal magnetic field. The green and yellow bars indicate energy deposits in the liquid argon and scintillating-tile calorimeters, clustered in a structure typical of a di-jet event. The transverse momentum of the jets are about 200 GeV and 170 GeV.

  10. Power Distribution for the ATLAS LAr Trigger Digitizer Board

    CERN Document Server

    Lazzaroni, Massimo; The ATLAS collaboration; Latorre, Stefano

    2015-01-01

    The R&D activity for the design of the power distribution section of the ATLAS Liquid Argon (LAr) Calorimeter Trigger Digitizer Board board (LTDB) is presented. Many aspects concerning the radiation hardness and the ability to operate of Point-of-load converters also in presence of high magnetic fields are covered. Devices designed by CERN, designed for experiments at LHC, have been used and their capability for implementation in the LTDB has been exploited with the aim to have a power distribution section with the required performances.

  11. ATLAS LAr Phase upgrade of the Front End Electronics

    CERN Document Server

    Newcomer, Mitchel; The ATLAS collaboration

    2016-01-01

    The Phase II upgrade of the ATLAS Liquid Argon detector includes a 17 bit dynamic range front end amplifier with a two or three gain multi‐pole shaper employing CR‐(RC)n shaping. Each gain stage of the shaper will be followed by a 40Msps, 14b dynamic range, 12‐13b ENOB digitizer, serializer and fiber optic driver. A study is underway to see if a single technology (65nm or 130nm CMOS) will be suitable for all blocks up to the optical Link, enabling consideration of the development a Front End System On a Chip (FESOC).

  12. Argon-39 Background in DUNE Photon Detectors

    Science.gov (United States)

    Sinev, Gleb; DUNE Collaboration

    2016-03-01

    The Deep Underground Neutrino Experiment (DUNE) is a 40-kt liquid argon detector that will be constructed 5000 ft underground in the Sanford Underground Research Facility in order to study neutrino and proton decay physics. Instrumenting liquid argon with photon detectors to record scintillation in addition to the ionization signal can significantly improve time and energy resolution of the experiment. Argon produces light with wavelength of 128 nm. The reference design for the photon detectors includes acrylic bars covered in wavelength shifter, where the scintillation light can be captured and reemitted with longer wavelengths, then detected using silicon photomultipliers. Radiological backgrounds may noticeably deteriorate the photon detection system performance, especially for low-energy interactions. A particularly important background comes from argon-39 decays, because argon-39 is present in natural argon that will be used in DUNE and the background rate increases with the size of the experiment. The effect of the argon-39 background has been studied and is presented in this talk.

  13. The liquid argon calorimeter subsystem

    International Nuclear Information System (INIS)

    During the past several months, Tennessee, Mississippi, and the Oak Ridge National Laboratory have been coordinating efforts to benchmark the CALOR89 code system against the DO and HELIOS prototype calorimeter data, and to use the CALOR89 system to generate currently needed data for radiation damage studies, signal collection time, and compensation characteristics of various calorimeter designs. This report describes these results and gives our plans and projected budgets for the following year. 8 refs., 5 figs

  14. Combined performance studies for electrons at the 2004 ATLAS combined test-beam

    International Nuclear Information System (INIS)

    In 2004 at the ATLAS (A Toroidal LHC ApparatuS) combined test beam, one slice of the ATLAS barrel detector (including an Inner Detector set-up and the Liquid Argon calorimeter) was exposed to particles from the H8 SPS beam line at CERN. It was the first occasion to test the combined electron performance of ATLAS. This paper presents results obtained for the momentum measurement p with the Inner Detector and for the performance of the electron measurement with the LAr calorimeter (energy E linearity and resolution) in the presence of a magnetic field in the Inner Detector for momenta ranging from 20 GeV/c to 100 GeV/c. Furthermore the particle identification capabilities of the Transition Radiation Tracker, Bremsstrahlungs-recovery algorithms relying on the LAr calorimeter and results obtained for the E/p ratio and a way how to extract scale parameters will be discussed.

  15. Low-noise current preamplifier for the electromagnetic calorimeter of ATLAS

    International Nuclear Information System (INIS)

    The ATLAS detector at CERN is an experiment on the future LHC collider, which seeks new particles, like the Higgs boson, to complete the standard model and develop the supersymmetry model. An important sub-detector in ATLAS is the Liquid Argon calorimeter which measures the energy of electrons and photons. The calorimeter precision is partially limited by the electronic noise of the input preamplifiers, which is then particularly a point of attention. The main study of this thesis is a 'warm' current preamplifier ('0T') placed outside the cryostat, the signal being driven on cables. First, the main characteristics of another type of preamplifier placed in the calorimeter are studied. Then the 0T is modelled, particularly the effects of a cable on the electronic noise and the signal. Different versions are studied, whose measurements are in good agreement with expected values. In the ATLAS Liquid Argon calorimeter conditions the 0T performance are very competitive with a 'cold' preamp, and has the advantage of reliability. Also their location outside the cryostat allows maintenance. But the cable impedance is higher than the input impedance of a cold preamplifier, which is a drawback according to capacitive crosstalk between neighbouring channels. The signal crosstalk is higher, but acceptable. As well, the noise correlation between two channels as a function of cable length is shown as negligible for cable lengths used. The noise autocorrelation function is also studied to optimize a multi-sampling filtering. The model and measurements are in excellent agreement. The 0T has been chosen to equip 200,000 channels of the ATLAS Liquid Argon calorimeter. (author)

  16. Liquid argon as active shielding and coolant for bare germanium detectors. A novel background suppression method for the GERDA 0νββ experiment

    International Nuclear Information System (INIS)

    Two of the most important open questions in particle physics are whether neutrinos are their own anti-particles (Majorana particles) as required by most extensions of the StandardModel and the absolute values of the neutrino masses. The neutrinoless double beta (0νββ) decay, which can be investigated using 76Ge (a double beta isotope), is the most sensitive probe for these properties. There is a claim for an evidence for the 0νββ decay in the Heidelberg-Moscow (HdM) 76Ge experiment by a part of the HdM collaboration. The new 76Ge experiment Gerda aims to check this claim within one year with 15 kg.y of statistics in Phase I at a background level of ≤10-2 events/(kg.keV.y) and to go to higher sensitivity with 100 kg.y of statistics in Phase II at a background level of ≤10-3 events/(kg.keV.y). In Gerda bare germanium semiconductor detectors (enriched in 76Ge) will be operated in liquid argon (LAr). LAr serves as cryogenic coolant and as high purity shielding against external background. To reach the background level for Phase II, new methods are required to suppress the cosmogenic background of the diodes. The background from cosmogenically produced 60Co is expected to be ∝2.5.10-3 events/(kg.keV.y). LAr scintillates in UV (λ=128 nm) and a novel concept is to use this scintillation light as anti-coincidence signal for background suppression. In this work the efficiency of such a LAr scintillation veto was investigated for the first time. In a setup with 19 kg active LAr mass a suppression of a factor 3 has been achieved for 60Co and a factor 17 for 232Th around Qββ = 2039 keV. This suppression will further increase for a one ton active volume (factor O(100) for 232Th and 60Co). LAr scintillation can also be used as a powerful tool for background diagnostics. For this purpose a new, very stable and robust wavelength shifter/reflector combination for the light detection has been developed, leading to a photo electron (pe) yield of as much as 1.2 pe

  17. Liquid argon as active shielding and coolant for bare germanium detectors. A novel background suppression method for the GERDA 0{nu}{beta}{beta} experiment

    Energy Technology Data Exchange (ETDEWEB)

    Peiffer, J.P.

    2007-07-25

    Two of the most important open questions in particle physics are whether neutrinos are their own anti-particles (Majorana particles) as required by most extensions of the StandardModel and the absolute values of the neutrino masses. The neutrinoless double beta (0{nu}{beta}{beta}) decay, which can be investigated using {sup 76}Ge (a double beta isotope), is the most sensitive probe for these properties. There is a claim for an evidence for the 0{nu}{beta}{beta} decay in the Heidelberg-Moscow (HdM) {sup 76}Ge experiment by a part of the HdM collaboration. The new {sup 76}Ge experiment Gerda aims to check this claim within one year with 15 kg.y of statistics in Phase I at a background level of {<=}10{sup -2} events/(kg.keV.y) and to go to higher sensitivity with 100 kg.y of statistics in Phase II at a background level of {<=}10{sup -3} events/(kg.keV.y). In Gerda bare germanium semiconductor detectors (enriched in {sup 76}Ge) will be operated in liquid argon (LAr). LAr serves as cryogenic coolant and as high purity shielding against external background. To reach the background level for Phase II, new methods are required to suppress the cosmogenic background of the diodes. The background from cosmogenically produced {sup 60}Co is expected to be {proportional_to}2.5.10{sup -3} events/(kg.keV.y). LAr scintillates in UV ({lambda}=128 nm) and a novel concept is to use this scintillation light as anti-coincidence signal for background suppression. In this work the efficiency of such a LAr scintillation veto was investigated for the first time. In a setup with 19 kg active LAr mass a suppression of a factor 3 has been achieved for {sup 60}Co and a factor 17 for {sup 232}Th around Q{sub {beta}}{sub {beta}} = 2039 keV. This suppression will further increase for a one ton active volume (factor O(100) for {sup 232}Th and {sup 60}Co). LAr scintillation can also be used as a powerful tool for background diagnostics. For this purpose a new, very stable and robust wavelength

  18. Argon plasma coagulation

    Directory of Open Access Journals (Sweden)

    Zenker, Matthias

    2008-03-01

    Full Text Available Argon Plasma Coagulation (APC is an application of gas discharges in argon in electrosurgery, which is increasingly used especially in endoscopy. The major application fields are haemostasis, tissue devitalization and tissue reduction.This review describes the physics and technology of electrosurgery and APC. Some characteristics of the argon discharge are shown and discussed, and thermal effects in biological tissue are described. Subsequently, examples of medical applications are given.

  19. Pulse simulations and heat flow measurements for the ATLAS Forward Calorimeter under high-luminosity conditions

    CERN Document Server

    AUTHOR|(SzGeCERN)758133; Zuber, Kai

    The high luminosity phase of the Large Hadron Collider at CERN is an important step for further and more detailed studies of the Standard Model of particle physics as well as searches for new physics. The necessary upgrade of the ATLAS detector is a challenging task as the increased luminosity entails many problems for the different detector parts. The liquid-argon Forward Calorimeter suffers signal-degradation effects and a high voltage drop of the supply potential under high-luminosity conditions. It is possible that the argon starts to boil due to the large energy depositions. The effect of the high-luminosity environment on the liquid-argon Forward Calorimeter has been simulated in order to investigate the level of signal degradation. The results show a curvature of the triangular pulse shape that appears prolonged when increasing the energy deposit. This effect is caused by the drop in the electric potential that produces a decrease in the electric field across the liquid-argon gap in the Forward Calorim...

  20. ATLAS TV PROJECT

    CERN Multimedia

    2005-01-01

    Building 130 at CERN: liquid Argon calorimeter Sequence 1 00.06 Shots of giant Argon chamber. Martin Aleska and colleagues working. Assembly and testing work on 2 endcap chambers. 12.12 Spot interview - men looking for leaks. (2 takes) 14.10 General shots of apparatus. Sequence 2 15.48 Interview Martin Aleksa By liquid Argon calorimeter and containing shots of detector. (Retake 16.36). Sequence 3 Model of the 12 detector system. 25.37 Martin Aleksa voice over explanation. And spot interview BCU cutaways.

  1. ATLAS electromagnetic calorimeter, construction and test of a large scale system

    CERN Document Server

    Tayalati, Y

    2004-01-01

    The construction of the ATLAS liquid argon presamplers and accordion calorimeters are about to be completed. The first half-length barrel wheel is already installed in the cryostat and assembly of the second wheel is about to be finished. Modules for the first end-cap wheel are ready and the assembly of the first wheel is well under way. From 55000 output channels of the first barrel wheel only four channels are malfunctioning and a very small fraction of high voltage area has showed problems, ~0.15%. After a review of the construction, production, and assembly, results concerning the energy and position resolution are shown.

  2. ATLAS event at 13 TeV - First stable beam, 3 June 2015 - run: 266904

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Display of a proton-proton collision event recorded by ATLAS on 3 June 2015, with the first LHC stable beams at a collision energy of 13 TeV. Tracks reconstructed from hits in the inner tracking detector are shown as arcs curving in the solenoidal magnetic field. The yellow rectangles along with the red and green bars indicate energy deposits in the liquid argon and scintillating-tile calorimeters. Tracks originate from several vertices, indicating multiple proton-proton interactions (also known as pile-up ) recorded in one event.

  3. ATLAS event at 13 TeV - First stable beam, 3 June 2015 - run: 266904

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Display of a proton-proton collision event recorded by ATLAS on 3 June 2015, with the first LHC stable beams at a collision energy of 13 TeV. Tracks reconstructed from hits in the inner tracking detector are shown as arcs curving in the solenoidal magnetic field. The green and yellow bars indicate energy deposits in the liquid argon and scintillating-tile calorimeters, clustered in a structure typical of a di-jet event. The transverse momentum of the jets are about 200 GeV and 170 GeV.

  4. ATLAS 4-jet event at 13 TeV - 21 May 2015 - Run 265545 Event 2501742

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Display of a proton-proton collision event recorded by ATLAS on 21 May 2015 at a collision energy of 13 TeV. Tracks reconstructed from hits in the inner tracking detector are shown as arcs curving in the solenoidal magnetic field. The green and yellow bars indicate energy deposits in the Liquid Argon and Scintillating Tile calorimeters, clustered in a structure typical of a 4-jet event. The most energetic jet has a transverse energy of more than 200 GeV.

  5. Muon Results from the EMEC/HEC Combined Run corresponding to the ATLAS Pseudorapidity region 1.6 < eta < 1.8

    CERN Document Server

    Cojocaru, C; Soukup, J; Vincter, M G; Datskov, V I; Fedorov, A; Golubyh, S M; Javadov, N; Kalinnikov, V; Kakurin, S; Kazarinov, M; Kukhtin, V; Ladygin, E; Lazarev, A B; Neganov, A B; Pisarev, I; Rousakovitch, N; Serochkin, E; Shilov, S N; Shalyugin, A N; Usov, Yu; Bruncko, Dusan; Chytracek, R; Kladiva, E; Strízenec, P; Barreiro, F; García, G; Labarga, F; Rodier, S; Del Peso, J; Heldmann, M; Jakobs, K; Köpke, L; Othegraven, R; Schroff, D; Thomas, J; Zeitnitz, C; Barrillon, P; Benchouk, C; Djama, F; Henry-Coüannier, F; Hinz, L; Hubaut, F; Monnier, E; Olivier, C; Pralavorio, Pascal; Raymond, R; Sauvage, D; Serfon, C; Tisserant, S; Tóth, J; Azuelos, Georges; Leroy, C; Mehdiyev, R; Akimov, A; Blagov, M I; Komar, A; Snesarev, A A; Speransky, M N; Sulin, V; Yakimenko, M; Aderholz, M; Barillari, T; Bartko, H; Cwienk, W D; Fischer, A; Habring, J; Huber, J; Karev, A; Kiryunin, A E; Kurchaninov, L L; Menke, S; Mooshofer, P; Oberlack, H; Salihagic, D; Schacht, P; Chen, T; Ping, J; Qi, M; Aoulthenko, W; Kazanin, V; Kolatchev, G; Malychev, W; Maslennikov, A L; Pospelov, G E; Snopkov, R; Shousharo, A; Soukharev, A M; Talyshev, A A; Tikhonov, Yu A; Chekulaev, S V; Denisov, S; Levitsky, M; Minaenko, A A; Mitrofanov, G Ya; Moiseev, A; Pleskatch, A; Sytnik, V V; Zakamsky, L; Losty, Michael J; Oram, C J; Wielers, M; Birney, P; Fincke-Keeler, M; Gable, I; Hodges, T; Hughes, T; Ince, I; Kanaya, N; Keeler, Richard K; Langstaf, R; Lefebvre, M; Lenckowski, M; McPherson, R A; Braun, H; Thadome, J

    2004-01-01

    A full azimuthal $\\phi$-wedge of the ATLAS liquid argon end-cap calorimeter has been exposed to beams of electrons, muons and pions in the energy range $6\\,\\GeV\\le E\\le 200\\,\\GeV$ at the CERN SPS. The angular region studied corresponds to the ATLAS impact position around the pseudorapidity interval $1.6<|\\eta|<1.8$. The beam test set-up is described. A detailed study of the performance is given as well as the related intercalibration constants obtained. Following the ATLAS hadronic calibration proposal, a first study of the hadron calibration using a weighting ansatz is presented. The results are compared to predictions from Monte Carlo simulations, based on GEANT~3 and GEANT~4 models.

  6. Lunar exospheric argon modeling

    Science.gov (United States)

    Grava, Cesare; Chaufray, J.-Y.; Retherford, K. D.; Gladstone, G. R.; Greathouse, T. K.; Hurley, D. M.; Hodges, R. R.; Bayless, A. J.; Cook, J. C.; Stern, S. A.

    2015-07-01

    Argon is one of the few known constituents of the lunar exosphere. The surface-based mass spectrometer Lunar Atmosphere Composition Experiment (LACE) deployed during the Apollo 17 mission first detected argon, and its study is among the subjects of the Lunar Reconnaissance Orbiter (LRO) Lyman Alpha Mapping Project (LAMP) and Lunar Atmospheric and Dust Environment Explorer (LADEE) mission investigations. We performed a detailed Monte Carlo simulation of neutral atomic argon that we use to better understand its transport and storage across the lunar surface. We took into account several loss processes: ionization by solar photons, charge-exchange with solar protons, and cold trapping as computed by recent LRO/Lunar Orbiter Laser Altimeter (LOLA) mapping of Permanently Shaded Regions (PSRs). Recycling of photo-ions and solar radiation acceleration are also considered. We report that (i) contrary to previous assumptions, charge exchange is a loss process as efficient as photo-ionization, (ii) the PSR cold-trapping flux is comparable to the ionization flux (photo-ionization and charge-exchange), and (iii) solar radiation pressure has negligible effect on the argon density, as expected. We determine that the release of 2.6 × 1028 atoms on top of a pre-existing argon exosphere is required to explain the maximum amount of argon measured by LACE. The total number of atoms (1.0 × 1029) corresponds to ∼6700 kg of argon, 30% of which (∼1900 kg) may be stored in the cold traps after 120 days in the absence of space weathering processes. The required population is consistent with the amount of argon that can be released during a High Frequency Teleseismic (HFT) Event, i.e. a big, rare and localized moonquake, although we show that LACE could not distinguish between a localized and a global event. The density of argon measured at the time of LACE appears to have originated from no less than four such episodic events. Finally, we show that the extent of the PSRs that trap

  7. Missing Transverse Momentum Trigger Performance Studies for the ATLAS Calorimeter Trigger Upgrades

    Science.gov (United States)

    Stamas, Brianna; Parrish, Elliot; Lisi, Luc; Dudley, Christopher; Majewski, Stephanie

    2016-03-01

    The ATLAS Experiment is one of two general purpose detectors at the Large Hadron Collider at CERN in Geneva, Switzerland. In anticipation of discovering new physics, the detector will undergo numerous hardware upgrades including improvements to the Liquid Argon Calorimeter trigger electronics. For the upgrade, one component of the Level-1 trigger system will be the global feature extractor, gFEX, which will house three field programmable gate arrays (FPGAs). Specifically, in order to improve the missing transverse energy (ETmiss)trigger, an adapted topological clustering algorithm is being investigated for implementation on the FPGAs for reconstruction of proton-proton interactions in the ATLAS detector. Using simulated data, this study analyzes the performance of the adapted algorithm in software.

  8. Performance of an endcap prototype of the ATLAS accordion electromagnetic calorimeter

    CERN Document Server

    Gingrich, D M; Boos, E; Zhautykov, B O; Aubert, Bernard; Bazan, A; Beaugiraud, B; Boniface, J; Colas, Jacques; Jézéquel, S; Le Flour, T; Maire, M; Rival, F; Stipcevic, M; Thion, J; Van den Plas, D; Wingerter-Seez, I; Zitoun, R; Zolnierowski, Y; Chmeissani, M; Fernández, E; Garrido, L; Martínez, M; Padilla, C; Gordon, H A; Radeka, V; Rahm, David Charles; Stephani, D; Baisin, L; Berset, J C; Chevalley, J L; Gianotti, F; Gildemeister, O; Marin, C P; Nessi, Marzio; Poggioli, Luc; Richter, W; Vuillemin, V; Baze, J M; Gosset, L G; Lavocat, P; Lottin, J P; Mansoulié, B; Meyer, J P; Renardy, J F; Schwindling, J; Teiger, J; Collot, J; de Saintignon, P; Dzahini, D; Hostachy, J Y; Laborie, G; Mahout, G; Merchez, E; Pouxe, J; Hervás, L; Labarga, L; Scheel, C V; Chekhtman, A; Dargent, P; Dinkespiler, B; Etienne, F; Fassnacht, P; Fouchez, D; Martin, L; Martin, O; Miotto, A; Monnier, E; Nagy, E; Olivetto, C; Tisserant, S; Battistoni, G; Camin, D V; Cavalli, D; Costa, G; Cozzi, L; Resconi, S; Fedyakin, N N; Ferrari, A; Mandelli, L; Mazzanti, M; Perini, L; Sala, P R; Azuelos, Georges; Beaudoin, G; Depommier, P; León-Florián, E; Leroy, C; Roy, P; Serman, M; Augé, E; Chase, Robert L; Chollet, J C; de La Taille, C; Fayard, Louis; Fournier, D; Hrisoho, A T; Merkel, B; Noppe, J M; Parrour, G; Pétroff, P; Schaffer, A C; Seguin-Moreau, N; Serin, L; Tisserand, V; Vichou, I; Canton, B; David, J; Genat, J F; Imbault, D; Le Dortz, O; Savoy-Navarro, Aurore; Schwemling, P; Eek, L O; Lund-Jensen, B; Söderqvist, J; Lefebvre, M; Robertson, S; White, J

    1997-01-01

    The design and construction of a lead-liquid argon endcap calorimeter prototype using an accordion geometry and conceived as a sector of the inner wheel of the endcap calorimeter of the future ATLAS experiment at the LHC is described. The performance obtained using electron beam data is presented. The main results are an energy resolution with a sampling term below $11\\%/\\sqrt{E(\\rm GeV)}$ and a small local constant term, a good linearity of the response with the incident energy and a global constant term of 0.8\\% over an extended area in the rapidity range of $2.2 < \\eta <2.9$. These properties make the design suitable for the ATLAS electromagnetic endcap calorimeter.

  9. ATLAS - analysis of time-of-flight diffraction data from liquid and amorphous samples

    International Nuclear Information System (INIS)

    The purpose of this manual is to describe a package of data analysis routines which have been developed at the Rutherford Appleton Laboratory for the analysis of time-of-flight diffraction data from liquids, gases, and amorphous materials. There is no fundamental barrier to diffraction data being accurately analysed to structure factor or even pair correlation function within a very short time of the completion of the experiment. Section 1 describes the time-of-flight neutron diffraction experiment and looks at diffraction theory. Section 2 indicates the steps in data analysis of time-of-flight diffraction data and Section 3 gives details of how to run the procedures. (author)

  10. Upgrade plans for the ATLAS Forward Calorimeter at the HL-LHC

    CERN Document Server

    Rutherfoord, J; The ATLAS collaboration

    2012-01-01

    Although data-taking at CERN's Large Hadron Collider (LHC) is expected to continue for a number of years, plans are already being developed for operation of the LHC and associated detectors at an increased instantaneous luminosity about 5 times the original design value of 10^34 cm^-2 s^-1. The increased particle flux at this high luminosity (HL) will have an impact on many sub-systems of the ATLAS detector. In particular, in the liquid argon forward calorimeter (FCal), which was designed for operation at LHC luminosities, the associated increase in the ionization load at HL-LHC luminosities creates a number of problems which can degrade its performance. These include space-charge effects in the liquid argon gaps, excessive drop in potential across the gaps due to large HV supply currents through the protection resistors, and an increase in temperature which may cause the liquid argon to boil. One solution, which would require opening both End-Cap cryostats, is the construction and installation of new FCals w...

  11. Atlas SOHO Booster and Centaur Erection

    Science.gov (United States)

    1995-01-01

    The launch vehicle for the Solar Heliospheric Observatory (SOHO) mission is a two stage Atlas-IIAS (Atlas/Centaur). The Atlas, consists of a solid rocket booster stage powered by four Thiokol Castor IVA solid rocket boosters (SRB) and a core vehicle stage (booster and sustainer) powered by Rocketdyne MA-5A liquid propellant engines (RP-1 fuel and liquid oxygen). The multiple firing Centaur is powered by two Pratt and Whitney (RL10A-4) liquid hydrogen and liquid oxygen engines with extendible nozzles. This video shows the erection of the Atlas booster and transportation (to 36-B launching pad) and erection of the Centaur.

  12. Digital Filtering Performance in the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Hadley, D R; The ATLAS collaboration

    2010-01-01

    The ATLAS Level-1 Calorimeter Trigger is a hardware-based system designed to identify high-pT jets, elec- tron/photon and tau candidates, and to measure total and missing ET in the ATLAS Liquid Argon and Tile calorimeters. It is a pipelined processor system, with a new set of inputs being evaluated every 25ns. The overall trigger decision has a latency budget of 2µs, including all transmission delays. The calorimeter trigger uses about 7200 reduced granularity analogue signals, which are first digitized at the 40 MHz LHC bunch-crossing frequency, before being passed to a digital Finite Impulse Re- sponse (FIR) filter. Due to latency and chip real-estate constraints, only a simple 5-element filter with limited precision can be used. Nevertheless, this filter achieves a significant reduction in noise, along with improving the bunch-crossing assignment and energy resolution for small signals. The context in which digital filters are used for the ATLAS Level-1 Calorimeter Trigger is presented, before descr...

  13. Digital Filter Performance for the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Hadley, D R; The ATLAS collaboration

    2010-01-01

    The ATLAS Level-1 Calorimeter Trigger is a hardware-based system designed to identify high-pT jets, electron/photon and tau candidates, and to measure total and missing ET in the ATLAS Liquid Argon and Tile calorimeters. It is a pipelined processor system, with a new set of inputs being evaluated every 25ns. The overall trigger decision has a latency budget of 2µs, including all transmission delays. The calorimeter trigger uses about 7200 reduced granularity analogue signals, which are first digitized at the 40 MHz LHC bunch-crossing frequency, before being passed to a digital Finite Impulse Response (FIR) filter. Due to latency and chip real-estate constraints, only a simple 5-element filter with limited precision can be used. Nevertheless this filter achieves a significant reduction in noise, along with improving the bunch-crossing assignment and energy resolution for small signals. The context in which digital filters are used for the ATLAS Level-1 Calorimeter Trigger will be presented, before describing ...

  14. Validation of the Correction of the Energy Modulation Effect in eta in the LAr Calorimeter of ATLAS

    CERN Document Server

    Mohamed Ahmed Salem, Salma

    2016-01-01

    The ATLAS Electromagnetic Liquid Argon Calorimeter is used for measuring the energy of electromagnetic interacting particles. To validate results, different calibration procedures are performed with respect to different variables. The energy modulation in a single cell is one of the effects that need to be corrected. The eta modulation calibration was introduced to counteract this effect. Different quantities describing the deposited energy were used to test the calibration. This summer student project report focuses on showing the effect of the eta mod correction on different samples from data taken in run-II and Monte Carlo simulation.

  15. Evaluation of silicon-germanium (SiGe) bipolar technologies for use in an upgraded atlas detector

    International Nuclear Information System (INIS)

    Silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technologies promise several advantages over CMOS for the front-end readout electronics for the ATLAS upgrade. We have evaluated the relative merits of the latest generations of IBM SiGe HBT BiCMOS technologies, the 8WL and 8HP platforms. These 130 nm SiGe technologies show promise to operate at lower power than do CMOS technologies and would provide a viable alternative for the silicon strip detector and liquid argon calorimeter upgrades, provided that the radiation tolerance studies at multiple gamma and neutron irradiation levels, included in this investigation, show them to be sufficiently radiation tolerant.

  16. ATLAS di-jet event at 13 TeV - 21 May 2015 - Run 265573 Event 4417696

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Display of a proton-proton collision event recorded by ATLAS on 21 May 2015 at a collision energy of 13 TeV. Tracks reconstructed from hits in the inner tracking detector are shown as arcs curving in the solenoidal magnetic field. The green, red and yellow bars indicate energy deposits in the liquid argon and scintillating-tile calorimeters, clustered in a structure typical of a di-jet event. The most energetic jet has a transverse energy of about 45 GeV.

  17. Argon in action

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    Over the past few days, the SPS has been accelerating argon ions, which have started to be sent to the NA61/SHINE experiment. This operating mode, using a new type of ion, required a number of modifications to the accelerator.   Picture 1: a “super-cycle” of the SPS, featuring a proton cycle for the LHC, followed by an argon ion cycle for the North Area. Today, the accelerators are once again juggling particles and even performing completely new tricks. The SPS is supplying beams of argon ions for the first time, at energies never before achieved for this type of beam. They are destined for the NA61/SHINE experiment (see box) located in the North Area, which began receiving the beams on 11 February. Argon ions have a relatively large mass, as they consist of 40 nucleons, so they can be used in a similar way to lead ions. The main difficulty in accelerating them lies in the SPS, where the variation in acceleration frequency is limited. “The SPS was designed for a...

  18. Thermophysical properties of argon

    Energy Technology Data Exchange (ETDEWEB)

    Jaques, A.

    1988-02-01

    The entire report consists of tables of thermodynamic properties (including sound velocity, thermal conductivity and diffusivity, Prandtl number, density) of argon at 86 to 400/degree/K, in the form of isobars over 0.9 to 100 bars. (DLC)

  19. Qualification procedure of the electromagnetic calorimeter of the ATLAS detector

    International Nuclear Information System (INIS)

    LHC is the next collider based at CERN in Europe. The purpose of this machine is the Higgs boson and SUSY particles search. The detectors must have an excellent electromagnetic calorimetry to measure electron and photon energy. To maximize the signal to noise ratio for a low mass Higgs, it is fundamental to obtain a constant term as small as possible. LAPP is participating in the construction of the liquid argon electromagnetic calorimeter of the ATLAS collaboration. This technology is well adapted to the LHC experimental conditions. A systematic procedure to qualify the modules of this detector is an essential step to guarantee a 0,7% constant term, which is the collaboration objective. The procedure detailed in this thesis consists of quality monitoring during mechanical assembly and of a set of electrical tests such as electrical continuity, cell and cross-talk capacitance measurement, and high-voltage behaviour. For the whole test, it has been necessary to develop dedicated electronic cards, to develop measurement methods, and the whole operation software. Making the procedure automatic will guarantee the quality of each module during assembly, cabling, and test in liquid argon. (author)

  20. QCD physics in Atlas at the large hadron collider

    International Nuclear Information System (INIS)

    The Large Hadron Collider (LHC) is a proton-proton collider with a 14 TeV center of mass energy. The design luminosity is 1034 cm-1s-1 with beam collisions separated by 25 ns. The initial operation for physics will take place at a luminosity of 1033cm-1s-1 and it is expected that the integrated luminosity delivered in the first year will be 10 fb-1. This integrated luminosity will result in very large event samples for most processes, for example: ∼108 leptonic W decays, 104 γ's with Et > 500GeV and 104 jets with Et > 1TeV. As a result of the high statistics event samples, the understanding of most QCD processes at 14TeV will be systematics limited after the first year of running. The Atlas detector [1] is a general purpose detector designed to be sensitive to the many physics processes which are expected at the LHC. It contains high performance tracking using silicon detectors and a transition radiation tracker in a 2 Tesla solenoidal magnetic field, a high resolution electromagnetic calorimeter based on lead-liquid argon, a hadron calorimeter based on steel-scintillator and Cu/W-liquid argon, and a large instrumented air-core toroid magnet system for muon measurement. The basic performance characteristics of these systems are given in Table 1

  1. ATLAS LAr calorimeter degradation studies for HL-LHC

    Energy Technology Data Exchange (ETDEWEB)

    Novgorodova, Olga [Institut fuer Kern- und Teilchenphysik, Dresden (Germany)

    2015-07-01

    The future High Luminosity LHC upgrade (HL-LHC) will increase the luminosity by a factor of ten, which implies radiation hardness requirements for the LHC detectors. This requires to test the ATLAS Liquid Argon (LAr) calorimeters for higher intensities. In several test beam campaigns at IHEP/Protvino, the HiLum collaboration investigated small-size modules of the electromagnetic, hadronic, and forward calorimeters. The intensity of beam varied over a wide range (10{sup 6} to 10{sup 12} p/s) and beyond the maximum expected at HL-LHC for these calorimeters. The correlation between beam intensity and the electromagnetic calorimeter HV current signal is used to quantify the possible signal degradation. The results of the detector performance before and after operation in highest beam intensities are presented.

  2. Status of the Atlas Calorimeters: their performance during three years of LHC operation and plans for future upgrades.

    CERN Document Server

    Majewski, S; The ATLAS collaboration

    2014-01-01

    The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider (LHC) at CERN. Its calorimeter system measures the energy and direction of final state particles over the pseudorapidity range $|\\eta| < 4.9$. Accurate identification and measurement of the characteristics of electromagnetic objects (electrons/photons) are performed by liquid argon (LAr)-lead sampling calorimeters in the region $|\\eta| < 3.2$, using an innovative accordion geometry that provides a fast, uniform response without azimuthal gaps. This system played a critical role in the ATLAS analyses contributing to the Higgs boson discovery announced in 2012. The hadronic calorimeters measure the properties of hadrons, jets, and tau leptons, and also contribute to the measurement of the missing transverse energy and the identification of muons. A scintillator-steel sampling calorimeter (TileCal) is employed in the region $|\\eta| < 1.7$, while the region $1.5 < |\\eta| < 3.2$ is covered wi...

  3. Research and development for a free-running readout system for the ATLAS LAr Calorimeters at the high luminosity LHC

    Science.gov (United States)

    Hils, Maximilian

    2016-07-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the Large Hadron Collider (LHC) at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm-2 s-1. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5-7 times the design luminosity, with the goal of accumulating an integrated luminosity of 3000 fb-1. In the HL-LHC phase, the increased radiation levels and an improved ATLAS trigger system require a replacement of the Front-end (FE) and Back-end (BE) electronics of the LAr Calorimeters. Results from research and development of individual components and their radiation qualification as well as the overall system design will be presented.

  4. ATLAS - Liquid Cooling Systems

    CERN Document Server

    Bonneau, P.

    1998-01-01

    Photo 1 - Cooling Unit - Side View Photo 2 - Cooling Unit - Detail Manifolds Photo 3 - Cooling Unit - Rear View Photo 4 - Cooling Unit - Detail Pump, Heater and Exchanger Photo 5 - Cooling Unit - Detail Pump and Fridge Photo 6 - Cooling Unit - Front View

  5. The Argon Geochronology Experiment (AGE)

    Science.gov (United States)

    Swindle, T. D.; Bode, R.; Fennema, A.; Chutjian, A.; MacAskill, J. A.; Darrach, M. R.; Clegg, S. M.; Wiens, R. C.; Cremers, D.

    2006-01-01

    This viewgraph presentation reviews the Argon Geochronology Experiment (AGE). Potassium-Argon dating is shown along with cosmic ray dating exposure. The contents include a flow diagram of the Argon Geochronology Experiment, and schematic diagrams of the mass spectrometer vacuum system, sample manipulation mechanism, mineral heater oven, and the quadrupole ion trap mass spectrometer. The Laser-Induced Breakdown Spectroscopy (LIBS) Operation with elemental abundances is also described.

  6. Argon Welding Inside A Workpiece

    Science.gov (United States)

    Morgan, Gene E.

    1988-01-01

    Canopies convert large hollow workpiece into inert-gas welding chamber. Large manifold serves welding chamber for attachment of liner parts in argon atmosphere. Every crevice, opening and passageway provided with argon-rich environment. Weld defects and oxidation dramatically reduced; also welding time reduced.

  7. Upgrade of the ATLAS Calorimeters for Higher LHC Luminosities

    CERN Document Server

    Carbone, Ryne Michael; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will bring instantaneous and total luminosities which are a factor 5-7 beyond the original design of the ATLAS Liquid Argon (LAr) and Tile Calorimeters and their read-out systems. Due to radiation requirements and a new hardware trigger concept the read-out electronics will be improved in two phases. In Phase-I, a dedicated read-out of the LAr Calorimeters will provide higher granularity input to the trigger, in order to mitigate pile-up effects and to reduce the background rates. In Phase-II, completely new read-out electronics will allow a digital processing of all LAr and Tile Calorimeter channels at the full 40 MHz bunch-crossing frequency and a transfer of calibrated energy inputs to the trigger. Results from system design and performance of the developed read-out components, including fully functioning demonstrator systems already operated on the detector, will be reported. Furthermore, the current Forward Calorimeter (FCal) may suffer from signal degradation and argon bubble form...

  8. Upgrade of the ATLAS Calorimeters for Higher LHC Luminosities

    CERN Document Server

    ATLAS Tile Collaboration; The ATLAS collaboration

    2015-01-01

    The upgrade of the LHC will bring instantaneous and total luminosities which are a factor 5-7 beyond the original design of the ATLAS Liquid Argon (LAr) and Tile Calorimeters and their read-out systems. Due to radiation requirements and a new two-level hardware trigger concept the read-out electronics will be improved in two phases. In Phase-I, a dedicated read-out of the LAr Calorimeters will provide higher granularity input to the trigger, in order to mitigate pile-up effects and to reduce the background rates. In Phase-II, completely new read-out electronics will allow a digital processing of all LAr and Tile Calorimeter channels at full 40 MHz bunch-crossing frequency and a transfer of calibrated energy inputs to the trigger. Results from system design and performance of the developed read-out components, including fully functioning demonstrator systems already operated on the detector, will be reported. Furthermore, the current Forward Calorimeter (FCal) may suffer from signal degradation and argon bubbl...

  9. Test Results of a 1.2 kg/s Centrifugal Liquid Helium Pump for the ATLAS Superconducting Toroid Magnet System

    CERN Document Server

    Pengo, R; Passardi, Giorgio; Pirotte, O; ten Kate, H H J

    2002-01-01

    The toroid superconducting magnet of ATLAS-LHC experiment at CERN will be indirectly cooled by means of forced flow of liquid helium at about 4.5 K. A centrifugal pump will be used, providing a mass flow of 1.2 kg/s and a differential pressure of 40 kPa (ca. 400 mbar) at about 4300 rpm. Two pumps are foreseen, one for redundancy, in order to feed in parallel the cooling circuits of the Barrel and the two End-Caps toroid magnets. The paper describes the tests carried out at CERN to measure the characteristic curves, i.e. the head versus the mass flow at different rotational speeds, as well as the pump total efficiency. The pump is of the "fullemission" type, i.e. with curved blades and it is equipped with an exchangeable inducer. A dedicated pump test facility has been constructed at CERN, which includes a Coriolis-type liquid helium mass flow meter. This facility is connected to the helium refrigerator used for the tests at CERN of the racetrack magnets of the Barrel and of the End-Cap toroids.

  10. The ATLAS cryostat comes into the lime-light

    CERN Multimedia

    2002-01-01

    Jean-Jacques Aubert, director of IN2P3, addresses the teams involved in the ATLAS electromagnetic calorimeter. At the rear, the barrel cryostat being equipped. In response to an invitation from IN2P3, the French national institute for nuclear and particle physics, the ATLAS experiment teams have celebrated progress made in the construction of their Liquid Argon Detector. In particular they wanted to salute the arrival of the cryostat for one of the end-caps, built by the company Simic in Italy. The second is expected at the end of January 2003. The cryostats are the fruit of a collaboration between IN2P3, the Max Planck Institute in Munich and the German Ministry for education and research (BMBF). The barrel cryostat arrived from Japan last year. The three cryostats will contain four types of different detectors made by the collaboration. They will contain in total nearly 400 modules including electromagnetic modules. More than half the modules for one of the two electromagnetic calorimeter barrels have bee...

  11. Simulation der Energierekonstruktion der verbesserten Flüssigargon-Kalorimeter-Auslese bei ATLAS

    CERN Document Server

    AUTHOR|(SzGeCERN)758889; Zuber, Kai

    The Large Hadron Collider (LHC) at CERN is designed to accelerate particles close to the speed of light and to collide them. Several particle detectors investigate the proton-proton collisions. One of them is the ATLAS detector, which consists of different sub-detectors. The purpose of one of them, the Liquid-Argon (LAr) calorimeter, is to measure the energy of particles. The deposited energy from particles is processed, analysed and reconstructed in the end by filter algorithms in the readout electronics. Since there are many particle interactions for each bunch crossing the ATLAS detector has a trigger system to select only the interactions of physical interest. For 2018 an upgrade of the LHC and ATLAS is planned to increase the luminosity. Which is a big challenge for the trigger system. Therefore an upgrade of the readout electronics of the LAr calorimeter is planned. Simulations are used and presented to evaluate the design of the future readout electronics. In this thesis the analog pulse shapes of the ...

  12. Readout Electronics for the ATLAS LAr Calorimeter at HL-LHC

    CERN Document Server

    Chen, H; The ATLAS collaboration

    2011-01-01

    The ATLAS experiment is one of the two general-purpose detectors designed to study proton-proton collisions (14 TeV in the center of mass) produced at the Large Hadron Collider (LHC) and to explore the full physics potential of the LHC machine at CERN. The ATLAS Liquid Argon (LAr) calorimeters are high precision, high sensitivity and high granularity detectors designed to provide precision measurements of electrons, photons, jets and missing transverse energy. ATLAS (and its LAr Calorimeters) has been operating and collecting p-p collisions at LHC since 2009. The on-detector electronics (front-end) part of the current readout electronics of the calorimeters measures the ionization current signals by means of preamplifiers, shapers and digitizers and then transfers the data to the off-detector electronics (back-end) for further elaboration, via optical links. Only the data selected by the level-1 calorimeter trigger system are transferred, achieving a bandwidth reduction to 1.6 Gbps. The analog trigger sum sig...

  13. Microwave Argon Plasma Torch

    Science.gov (United States)

    Felizardo, Edgar; Pencheva, Mariana; Benova, Evgenia; Dias, Fransisco; Tatarova, Elena

    2009-10-01

    A theoretical and experimental investigation of a microwave (2.45 GHz) Argon plasma torch driven by a surface wave is presented. The theoretical model couples in a self-consistent way the wave electrodynamics and the electron and heavy particle kinetics. The set of coupled equations includes: Maxwell's equations, the electron Boltzmann equation, including electron-electron collisions, and the particle balance equations for electrons, excited atoms (4s, 4p, 3d, 5s, 5p, 4d, 6s), and atomic (Ar^+) and molecular ions (Ar2^+). The input parameters of the model are: gas pressure (760 Torr), plasma radius (R = 0.75 cm), dielectric permittivity (ɛd = 4.0) and tube thickness (d = 0.15 cm) as well as the measured axial profile of the gas temperature (3500 K - 1500 K). The latter was determined from measurements of the rotational temperature of the OH molecular band in the range 306 - 315 nm. Phase and amplitude sensitive recording provides the data for the axial wavenumber and wave attenuation coefficient. The wavenumber decreases along the generated plasma torch. The electron density (Ne) axial profile as determined from measurements of Hβ Stark broadening is in agreement with the theoretical one.

  14. Electrical conductivity of compressed argon

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, R. [Univ. Regensburg (Germany); Windl, W.; Collins, L.; Kress, J.; Kwon, I. [Los Alamos National Lab., NM (United States)

    1997-10-01

    The authors report calculations of the electrical conductivity of solid argon as a function of compression within the density functional local density approximation formulation for a norm-conserving pseudopotential using both electron-phonon coupling and molecular dynamics techniques.

  15. Performance of the ATLAS Calorimeters and Commissioning for LHC Run-2

    CERN Document Server

    Rossetti, Valerio; The ATLAS collaboration

    2015-01-01

    The ATLAS general-purpose experiment at the Large Hadron Collider (LHC) is equipped with electromagnetic and hadronic liquid-argon (LAr) calorimeters and a hadronic scintillator-steel sampling calorimeter (TileCal) for measuring energy and direction of final state particles in the pseudorapidity range $|\\eta| < 4.9$. The calibration and performance of the calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb$^{-1}$ of data have been collected at the center-of-mass energies of 7 and 8~TeV. Results on the calorimeter operation, monitoring and data quality, as well as their performance will be presented, including the calibration and stability of the electromagnetic scale, response uniformity and time resolution. These results demonstrate that the LAr and Tile calorimeters perform excellently within their design requirements. The calorimetry system thu...

  16. Evaluation of the local hadronic calibration with combined beam-test data for the endcap and forward calorimeters of ATLAS in the pseudorapidity region 2.5<|η|<4.0

    International Nuclear Information System (INIS)

    The local hadronic calibration scheme developed for the reconstruction and calibration of jets and missing transverse energy in ATLAS has been evaluated using data obtained during combined beam tests of modules of the ATLAS liquid argon endcap and forward calorimeters. These tests covered the pseudorapidity range of 2.5<|η|<4.0. The analysis has been performed using special sets of calibration weights and corrections obtained with the GEANT4 simulation of a detailed beam-test setup. The evaluation itself has been performed through the careful study of specific calorimeter performance parameters such as e.g. energy response and resolution, shower shapes, as well as different physics lists of the GEANT4 simulation.

  17. Test and study of the barrel pre-sampler of the Atlas detector

    International Nuclear Information System (INIS)

    This study was made in the framework of the construction of the barrel pre-sampler which will equip the front face of the ATLAS electromagnetic calorimeter. The pre sampler consists of a thin active layer of 11 mm liquid argon. Its purpose is to take into account the energy loss of particles in the upstream material. A series of tests has been elaborated in order to check different pre-sampler components. Two pre-sampler sectors (1/32 of the detector) have been constructed in their final version by the ATLAS pre-sampler collaboration and assembled at ISN in Grenoble, where they were tested at room and liquid nitrogen temperatures rising a dedicated test bench. The performances: high voltage behaviour, electronic response to a test pulse, noise of the detection cells, cross-talk, etc... satisfy the requirements. Then, these two sectors were mounted at CERN in front of one electromagnetic calorimeter module and tested in a beam in 1998 and 1999. Test beam data analysis, compared to Monte Carlo simulations, have shown that the pre-sampler performs its role correctly. Energy resolution as a function of the amount of upstream material, linearity and uniformity have been measured for the pre-sampler plus electromagnetic calorimeter system. (author)

  18. Fano factor in pure argon

    International Nuclear Information System (INIS)

    The Fano factor for 5.3 MeV alpha particles in pure argon has been measured with a gridded ionization chamber and estimated to be 0.20 (+0.01-0.02). The obtained value is consistent with the theoretical value if the contribution of elastic nuclear collisions to the Fano factor is taken into the consideration. There is no appreciable difference between the values for pure argon and for a gas mixture of Ar (10%)CH4 obtained in the previous measurement. (orig.)

  19. Supporting ATLAS

    CERN Multimedia

    maximilien brice

    2003-01-01

    Eighteen feet made of stainless steel will support the barrel ATLAS detector in the cavern at Point 1. In total, the ATLAS feet system will carry approximately 6000 tons, and will give the same inclination to the detector as the LHC accelerator.

  20. Supporting ATLAS

    CERN Multimedia

    2003-01-01

    Eighteen feet made of stainless steel will support the barrel ATLAS detector in the cavern at Point 1. In total, the ATLAS feet system will carry approximately 6000 tons, and will give the same inclination to the detector as the LHC accelerator. The installation of the feet is scheduled to finish during January 2004 with an installation precision at the 1 mm level despite their height of 5.3 metres. The manufacture was carried out in Russia (Company Izhorskiye Zavody in St. Petersburg), as part of a Russian and JINR Dubna in-kind contribution to ATLAS. Involved in the installation is a team from IHEP-Protvino (Russia), the ATLAS technical co-ordination team at CERN, and the CERN survey team. In all, about 15 people are involved. After the feet are in place, the barrel toroid magnet and the barrel calorimeters will be installed. This will keep the ATLAS team busy for the entire year 2004.

  1. Thermal decomposition of lanthanum(III) butyrate in argon atmosphere

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Yue, Zhao; Xiao, Tang;

    2013-01-01

    The thermal decomposition of La(C3H7CO2)3·xH2O (x≈0.82) was studied in argon during heating at 5K/min. After the loss of bound H2O, the anhydrous butyrate presents at 135°C a phase transition to a mesophase, which turns to an isotropic liquid at 180°C. The decomposition of the anhydrous butyrate ...

  2. Mongolian Atlas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Climatic atlas dated 1985, in Mongolian, with introductory material also in Russian and English. One hundred eight pages in single page PDFs.

  3. Binocular indirect argon laser photocoagulator.

    OpenAIRE

    Mizuno, K

    1981-01-01

    The binocular indirect argon laser photocoagulator was newly designed to enable visualisation of the entire fundus during panretinal laser photocoagulation and to treat retinal tears immediately after buckling procedures of the sclera. The lamp housing of the binocular ophthalmoscope was remodelled and adjusted so that the laser beam and illuminating light are coaxial after leaving the ophthalmoscope. The blocking filter was permanently fixed in the eye-pieces to lighten the weight of the oph...

  4. Separation of seven arsenic compounds by high performance liquid chromatography with on-line detection by hydrogen-argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, S. H.; Larsen, Erik Huusfeldt; Pritzl, G.; Cornett, C.

    1992-01-01

    signal-to-noise ratio of the on-line AAS detector was optimized. This involved the use of the hydrogen-argon-entrained air flame, a slotted tube atom trap in the flame for signal enhancement, electronic noise damping and a high-intensity light source. The detection limits in mu-g cm-3, using 100 mm3...... injections of mixtures of arsenic standards into the HPLC system were: arsenite, As(III) 1.1; arsenate, As(V) 1.4; MMA 1.4; DMA 0.7; AsB 0.3; AsC 0.5; and the TMAs 0.4. The HPLC-AAS system was used for the analysis of arsenic species in aqueous extracts of soil samples from a polluted land site. Only...

  5. Insertion of the first half-barrel of the ATLAS electromagnetic calorimeter into its cryostat

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The first cylinder of the ATLAS electromagnetic calorimeter barrel and the presampler have been inserted in the cryostat.The ATLAS electromagnetic calorimeter is intended to detect electrons, positrons and photons by measuring the energy they deposit on being absorbed. The cylinder of the calorimeter is in two halves, that will be sunk in a liquid-argon bath cooled to 90 kelvin (-180°C). Each half-barrel is 3.2 metres long, 53 cm thick and formed by assembling 16 modules. Each module is made up of alternate lead absorbers and electrodes pressed into 64 layers folded accordion-fashion. The presampler, set up inside the cylinder, is an integral part of the calorimeter system: It measures the energy lost by a particle before it reaches the calorimeter. To ensure an ultra-clean environment, a tent (visible here) was erected round the calorimeter and entry point to the cryostat. The detector and presampler, fitted together, could then be slid gradually into the cryostat like a drawer. To do so, the insertion team...

  6. Insertion of the first half-barrel of the ATLAS electromagnetic calorimeter into its cryostat

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The first cylinder of the ATLAS electromagnetic calorimeter barrel and the presampler have been inserted in the cryostat. The ATLAS electromagnetic calorimeter is intended to detect electrons, positrons and photons by measuring the energy they deposit on being absorbed. The cylinder of the calorimeter is in two halves, that will be sunk in a liquid-argon bath cooled to 90 kelvin (-180°C). Each half-barrel is 3.2 metres long, 53 cm thick and formed by assembling 16 modules. Each module is made up of alternate lead absorbers and electrodes pressed into 64 layers folded accordion-fashion. The presampler, set up inside the cylinder, is an integral part of the calorimeter system: It measures the energy lost by a particle before it reaches the calorimeter. To ensure an ultra-clean environment, a tent was erected round the calorimeter and entry point to the cryostat. The detector and presampler, fitted together, could then be slid gradually into the cryostat like a drawer. To do so, the insertion team had to fine-t...

  7. ATLAS level-1 calorimeter trigger hardware: initial timing and energy calibration

    International Nuclear Information System (INIS)

    The ATLAS Level-1 Calorimeter Trigger identifies high-pT objects in the Liquid Argon and Tile Calorimeters with a fixed latency of up to 2.5μs using a hardware-based, pipelined system built with custom electronics. The Preprocessor Module conditions and digitizes about 7200 pre-summed analogue signals from the calorimeters at the LHC bunch-crossing frequency of 40 MHz, and performs bunch-crossing identification (BCID) and deposited energy measurement for each input signal. This information is passed to further processors for object classification and total energy calculation, and the results are used to make the Level-1 trigger decision for the ATLAS detector. The BCID and energy measurement in the trigger depend on precise timing adjustments to achieve correct sampling of the input signal peak. Test pulses from the calorimeters were analysed to derive the initial timing and energy calibration, and first data from the LHC restart in autumn 2009 and early 2010 were used for validation and further optimization. The results from these calibration measurements are presented.

  8. Towards a measurement of the W-boson inclusive production cross section in the electron-neutrino channel in the Atlas experiment at LHC

    International Nuclear Information System (INIS)

    The charged W-boson will be abundantly produced at the Large Hadron Collider (LHC) in proton-proton collisions at a center-of-mass energy of 14 TeV: its frequency production is about 1 Hz at low luminosity. Its decay in the electron channel will have a clear signature in the ATLAS detector, defined by a high transverse momentum electron and a high missing transverse energy. The ATLAS detector is a multi-purposes detector made up of a tracker, an electromagnetic calorimeter, a hadronic calorimeter and a muon spectrometer. It is fully installed in its cavern and recorded data with the first LHC beam in September 2008. A first part of the thesis presents a full analysis strategy for the W-boson inclusive production cross section with the first ATLAS data, maximizing the inputs from real data with respect to simulated ones. The main contributions to the systematical uncertainty are identified and estimated: a measurement precision better than 10% will be reachable from the first phase of the experiment. A second part is dedicated to the time alignment of the liquid argon calorimeters readout channels, a required step to reach the nominal performances. Timing constants are computed from the data recorded in September 2008: they will allow a time alignment of all channels at a 2-3 ns level for the start-up. (author)

  9. Diphoton measurements with the ATLAS detector at the LHC: search for new resonances and study of diphoton production in association with jets.

    CERN Document Server

    AUTHOR|(SzGeCERN)735473; Delmastro, Marco

    This thesis studies pp collisions at $\\sqrt{s}=8$ TeV with pairs of photons in the final state, as collected by the ATLAS experiment at the LHC during 2012. The diphoton final state has proven to be crucial to the discovery of the Higgs boson. The motivation for searching for additional resonances decaying into two photons is very strong due to many models predicting an extended Higgs sector. At the same time, detailed measurements of diphoton cross sections are necessary to establish the quality of the theoretical predictions currently available for these processes. The measurement of photons by ATLAS relies on an excellent calibration of the electromagnetic calorimeter response. For this reason, studies related to the calibration of the photon response in the ATLAS Liquid Argon (LAr) calorimeter are initially performed, including a measurement of the calorimeter layer energy scale relative calibration using photons, and the potential need of an inter-calibration of the photon energy response as a function ...

  10. Results from the first use of low radioactivity argon in a dark matter search

    Science.gov (United States)

    Agnes, P.; Agostino, L.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Arisaka, K.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Bottino, B.; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadonati, L.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Covone, G.; Crippa, L.; D'Angelo, D.; D'Incecco, M.; Davini, S.; De Cecco, S.; De Deo, M.; De Vincenzi, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giganti, C.; Goretti, A. M.; Granato, F.; Grandi, L.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K.; Hungerford, E. V.; Ianni, Al.; Ianni, An.; James, I.; Jollet, C.; Keeter, K.; Kendziora, C. L.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Lombardi, P.; Luitz, S.; Ma, Y.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montanari, D.; Monte, A.; Montuschi, M.; Monzani, M.; Mosteiro, P.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Nelson, A.; Odrowski, S.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Savarese, C.; Segreto, E.; Semenov, D. A.; Shields, E.; Singh, P. N.; Skorokhvatov, M. D.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Vishneva, A.; Vogelaar, B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xu, J.; Yang, C.; Yoo, J.; Zavatarelli, S.; Zec, A.; Zhong, W.; Zhu, C.; Zuzel, G.; DarkSide Collaboration

    2016-04-01

    Liquid argon is a bright scintillator with potent particle identification properties, making it an attractive target for direct-detection dark matter searches. The DarkSide-50 dark matter search here reports the first WIMP search results obtained using a target of low-radioactivity argon. DarkSide-50 is a dark matter detector, using a two-phase liquid argon time projection chamber, located at the Laboratori Nazionali del Gran Sasso. The underground argon is shown to contain 39Ar at a level reduced by a factor (1.4 ±0.2 )×103 relative to atmospheric argon. We report a background-free null result from (2616 ±43 ) kg d of data, accumulated over 70.9 live days. When combined with our previous search using an atmospheric argon, the 90% C.L. upper limit on the WIMP-nucleon spin-independent cross section, based on zero events found in the WIMP search regions, is 2.0 ×10-44 cm2 (8.6 ×10-44 cm2 , 8.0 ×10-43 cm2 ) for a WIMP mass of 100 GeV /c2 (1 TeV /c2 , 10 TeV /c2 ).

  11. Results from the first use of low radioactivity argon in a dark matter search

    Energy Technology Data Exchange (ETDEWEB)

    Agnes, P. [Universite Paris Diderot (France). et al.

    2016-04-08

    Liquid argon is a bright scintillator with potent particle identification properties, making it an attractive target for direct-detection dark matter searches. The DarkSide-50 dark matter search here reports the first WIMP search results obtained using a target of low-radioactivity argon. DarkSide-50 is a dark matter detector, using two-phase liquid argon time projection chamber, located at the Laboratori Nazionali del Gran Sasso. The underground argon is shown to contain Ar-39 at a level reduced by a factor (1.4 +- 0.2) x 103 relative to atmospheric argon. We report a background-free null result from (2616 +- 43) kg d of data, accumulated over 70.9 live-days. When combined with our previous search using an atmospheric argon, the 90 % C.L. upper limit on the WIMP-nucleon spin-independent cross section based on zero events found in the WIMP search regions, is 2.0 x 10-44 cm2 (8.6 x 10-44 cm2, 8.0 x 10-43 cm2) for a WIMP mass of 100 GeV/c2 (1 TeV/c2 , 10 TeV/c2).

  12. ATLAS LAr Calorimeter Performance and Commissioning for LHC Run-2

    CERN Document Server

    Spettel, Fabian; The ATLAS collaboration

    2015-01-01

    The ATLAS detector was designed and built to study proton-proton colli- sions produced at the LHC at centre-of-mass energies up to 14 TeV and in- stantaneous luminosities up to $10^{34} \\text{cm}^{-2} \\text{s}^{-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\\eta|<3.2$, and for hadronic calorimetry in the region from $|\\eta|=1.5$ to $|\\eta|=4.9$. In the first LHC run a total luminosity of 27 $\\text{fb}^{-1}$ as been collected at center-of-mass energies of 7-8 TeV with very high operational efficiency of the LAr Calorimeters and excellent performance. The well calibrated and highly granular detector achieved its design values both in energy measurement as well as in direction resolution, which was a main ingredient for the successul discovery of a Higgs boson in the di-photon decay channel. The talk will give an overview of the procedures applied to calibrate the 180.000 read-out channels electronically as well as from using refe...

  13. The WArP Experiment: A Double-Phase Argon Detector for Dark Matter Searches

    International Nuclear Information System (INIS)

    Cryogenic noble liquids emerged in the previous decade as one of the best media to perform WIMP dark matter searches, in particular due to the possibility to scale detector volumes to multiton sizes. The WArP experiment was then developed as one of the first to implement the idea of coupling Argon in liquid and gas phase, in order to discriminate β/γ-interactions from nuclear recoils and then achieve reliable background rejection. Since its construction, other projects spawned, employing Argon and Xenon and following its steps. The WArP 100l detector was assembled in 2008 at the Gran Sasso National Laboratories (LNGS), as the final step of a years-long R&D programme, aimed at characterising the technology of Argon in double phase for dark matter detection. Though it never actually performed a physics run, a technical run was taken in 2011, to characterise the detector response

  14. ATLAS Story

    CERN Multimedia

    Nordberg, Markus

    2012-01-01

    This film produced in July 2012 explains how fundamental research connects to Society and what benefits collaborative way of working can and may generate in the future, using ATLAS Collaboration as a case study. The film is intellectually inspired by the book "Collisions and Collaboration" (OUP) by Max Boisot (ed.), see: collisionsandcollaboration.com. The film is directed by Andrew Millington (OMNI Communications)

  15. MARLEY: Model of Argon Reaction Low Energy Yields

    Science.gov (United States)

    Gardiner, Steven; Bilton, Kyle; Grant, Christopher; Pantic, Emilija; Svoboda, Robert

    2015-10-01

    Core-collapse supernovae are sources of tremendous numbers of neutrinos with energies of up to about 50 MeV. In recent years, there has been growing interest in building detectors that are sensitive to supernova neutrinos. Such detectors can provide information about the initial stages of stellar collapse, early warning signals for light emission from supernovae, and opportunities to study neutrino oscillation physics over astronomical distances. In an effort to enable supernova neutrino detection in next-generation experiments like DUNE, the CAPTAIN collaboration plans to make the first direct measurement of cross sections for neutrino interactions on argon in the supernova energy regime. To help predict neutrino event signatures in the CAPTAIN liquid argon time projection chamber (LArTPC), we have developed a first-of-its-kind Monte Carlo event generator called MARLEY (Model of Argon Reaction Low Energy Yields). This generator attempts to model the complicated nuclear structure dependence of low-energy neutrino-nucleus reactions in sufficient detail for use in LArTPC simulations. In this talk we present some preliminary results calculated using MARLEY and discuss how the current version of the generator may be improved and expanded.

  16. Sodium aerosol formation in an argon flow over hot sodium

    International Nuclear Information System (INIS)

    Vapour evaporation, which partly forms aerosol, occurs when a cold gas flows over a hot liquid. A previous well-mixed model is extended to predict the final vapour plus aerosol content of such a flow in terms of its initial and final temperatures. The predictions are compared to results of the Copacabana II experiment in which argon passed over a sodium pool. Agreement is obtained for the final sodium density at moderate flow rates, and physical reasons are given as to why deviations occur at low and high flow rates. (author)

  17. Transition probabilities for argon I

    International Nuclear Information System (INIS)

    Transition probabilities for ArI lines have been calculated on the basis of the (j,k)-coupling scheme for more than 16000 spectral lines belonging to the transition arrays 4s-np (n=4 to n=9), 5s-np (n=5 to n=9), 6s-np (n=6 to n=9), 7s-np (n=8 to n=9), 4p-ns (n=5 to n=10), 5p-ns (n=6 to n=9), 6p-ns (n=7 to n=8), 4p-nd (n=3 to n=9), 5p-nd (n=4 to n=9), 3d-np (n=5 to n=9), 4d-np (n=6 to n=9), 5d-np (n=7 to n=9), 3d-nf (n=4 to n=9), 4d-nf (n=4 to n=9), 5d-nf (n=5 to n=9), 4f-nd (n=5 to n=9) 5f-nd (n=6 to n=9), 4f-ng (n=5 to n=9), 5f-ng (n=6 to n=9). Inso far as values by other authors exist, comparison is made with these values. It turns out that the results obtained in (j,k)-coupling are close to those obtained in intermediate coupling except for intercombination lines. For high principal and/or orbital quantum numbers the transition probabilities for a multiplet approach those of the corresponding transitions in atomic hydrogen. The calculated values are applied to construct a simplified argon-atom model, which reflects the real transition properties and which allows simplified but realistic non-equilibrium calculations for argon plasmas which deviate from local thermodynamic equilibrium (LTE)

  18. Development of high-strength and high-RRR aluminum-stabilized superconductor for the ATLAS thin solenoid

    CERN Document Server

    Wada, K; Sakamoto, H; Shimada, T; Nagasu, Y; Inoue, I H; Tsunoda, K; Endo, S; Yamamoto, A; Makida, Y; Tanaka, K; Doi, Y; Kondo, T

    2000-01-01

    The ATLAS central solenoid magnet is being constructed to provide a magnetic field of 2 Tesla in the central tracking part of the ATLAS detector at the LHC. Since the solenoid coil is placed in front of the liquid-argon electromagnetic calorimeter, the solenoid coil must be as thin (and transparent) as possible. The high-strength and high- RRR aluminum-stabilized superconductor is a key technology for the solenoid to be thinnest while keeping its stability. This has been developed with an alloy of 0.1 wt% nickel addition to 5N pure aluminum and with the subsequent mechanical cold working of 21% in area reduction. A yield strength of 110 MPa at 4.2 K has been realized keeping a residual resistivity ratio (RRR) of 590, after a heat treatment corresponding to coil curing at 130 degrees C for 15 hrs. This paper describes the optimization of the fabrication process and characteristics of the developed conductor. (8 refs).

  19. Research and Development for a Free-Running Readout System for the ATLAS LAr Calorimeters at the High Luminosity LHC

    CERN Document Server

    Hils, Maximilian; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the Large Hadron Collider (LHC) at centre-of-mass energies up to \\SI{14}{\\tera\\electronvolt} and instantaneous luminosities up to \\SI{d34}{\\per\\centi\\meter\\squared\\per\\second}. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5-7 times the design luminosity, with the goal of accumulating an integrated luminosity of \\SI{3000}{\\per\\femto\\barn}. In the HL-LHC phase, the increased radiation levels require a replacement of the front-end (FE) electronics of the LAr Calorimeters. Furthermore, the ATLAS trigger system is foreseen to increase the trigger accept rate and the trigger latency which requires a larger data volume to be buffered. Therefore, the LAr Calorimeter read-out will be exchanged with a new FE and a high bandwidth back-end (BE) system for receiving data from all \

  20. Research and Development for a Free-Running Readout System for the ATLAS LAr Calorimeters at the High Luminosity LHC

    CERN Document Server

    Hils, Maximilian; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34} \\text{cm}^{-2} \\text{s}^{-1}$. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5-7 times the design luminosity, with the goal of accumulating an integrated luminosity of $3000~\\text{fb}^{-1}$. In the HL-LHC phase, the increased radiation levels require a replacement of the front-end electronics of the LAr Calorimeters. Furthermore, the ATLAS trigger system is foreseen to increase the trigger accept rate by a factor 10 to 1 MHz and the trigger latency by a factor of 20 which requires a larger data volume to be buffered. Therefore, the LAr Calorimeter read-out will be exchanged with a new front-end and a high bandwidth back-end system for receiving data from all 186.000 channels at 40 MHz LHC bunch-crossing frequency and for off-detector buffering...

  1. Emissive spectra of shock-heated argon

    International Nuclear Information System (INIS)

    To study the radiant properties of argon under weak shock compression, an aluminum target filled with gaseous argon at ambient states was impacted by a tungsten alloy projectile which was launched from a two-stage light gun to 2.00 km/s. The radiant signals of single shock-compressed argon were recorded by a six-channel pyrometer and oscilloscopes, which varied with time linearly for the five channels from 405 nm to 700 nm and exponentially for the channel 800 nm, and the corresponding velocity of shock wave was determined to be 4.10 ± 0.09 km/s. By the present experiment, it has been shown that the absorbability of the shock-heated argon is low for visual light and the optical depths of argon gas turn from thin to thick as wavelengths gradually increase. The time-resolved spectra in the rising-front of the radiant signal in the re-shocked argon were recorded by means of an OMA, and strong emissive spectrum bands near 450 nm light-wave length but no linear spectrum were found. The emissive spectrum properties of shock-compression argon were qualitatively explained by the state parameters and ionization degree

  2. The WArP Experiment: A Double-Phase Argon Detector for Dark Matter Searches

    OpenAIRE

    Andrea Zani

    2014-01-01

    Cryogenic noble liquids emerged in the previous decade as one of the best media to perform WIMP dark matter searches, in particular due to the possibility to scale detector volumes to multiton sizes. The WArP experiment was then developed as one of the first to implement the idea of coupling Argon in liquid and gas phase, in order to discriminate β/γ -interactions from nuclear recoils and then achieve reliable background rejection. Since its construction, other projects spawned, employing Arg...

  3. ATLAS Recordings

    CERN Multimedia

    Steven Goldfarb; Mitch McLachlan; Homer A. Neal

    Web Archives of ATLAS Plenary Sessions, Workshops, Meetings, and Tutorials from 2005 until this past month are available via the University of Michigan portal here. Most recent additions include the Trigger-Aware Analysis Tutorial by Monika Wielers on March 23 and the ROOT Workshop held at CERN on March 26-27.Viewing requires a standard web browser with RealPlayer plug-in (included in most browsers automatically) and works on any major platform. Lectures can be viewed directly over the web or downloaded locally.In addition, you will find access to a variety of general tutorials and events via the portal.Feedback WelcomeOur group is making arrangements now to record plenary sessions, tutorials, and other important ATLAS events for 2007. Your suggestions for potential recording, as well as your feedback on existing archives is always welcome. Please contact us at wlap@umich.edu. Thank you.Enjoy the Lectures!

  4. Argon plasma irradiation of polypropylene

    International Nuclear Information System (INIS)

    Polypropylene samples were exposed to argon plasma discharge and the changes of the PP surface properties were studied by different methods. Surface wettability was derived from contact angle measured by standard goniometry and chemical structure of the plasma modified PP was studied using X-ray photoelectron spectroscopy (XPS) and by Rutherford backscattering spectroscopy (RBS), surface morphology and roughness of samples using AFM. Zeta potential of pristine and modified PP was determined with the SurPASS. The presence of incorporated oxygen in the PP surface layer, about 60 nm thick, was observed in RBS spectra. Oxygen concentration is a decreasing function of the depth. With progressing aging time the oxygen concentration on the PP surface decreases. Plasma treatment results in a rapid decrease of the contact angle, which increases again with increasing aging time. In XPS measurement the oxygen containing structures, created by the plasma treatment, were found on the very surface of the modified PP and the zeta potential being changed too. The significant difference in zeta potential between pristine and plasma treated PP clearly indicates that the plasma treatment leads to a more hydrophilic PP surface.

  5. Clinical periodontics with the argon laser

    Science.gov (United States)

    Finkbeiner, R. L.

    1995-04-01

    The argon laser has proven to be a valuable tool for the thermodynamic debridement of the periodontal lesion, incisions and tissue fusion. Illustrations of clinical applications and discussion of laser parameters will be provided.

  6. Opacity of Shock-Generated Argon Plasmas

    Institute of Scientific and Technical Information of China (English)

    王藩侯; 陈敬平; 周显明; 李西军; 经福谦; 孟续军; 孙永盛

    2001-01-01

    Argon plasmas with uniform density and temperature are generated by a planar shock wave through argon gas. The opacities of argon plasma, covering the thermodynamic states at temperatures of 1.4-2.2eV and in densities of 0.0083- 0.015 g/cm3, are investigated by measuring the emitted radiance versus time at several visible wavelengths. Comparison of the measured opacities with those calculated demonstrates that the average atom model can be used well to describe the essential transport behaviour of photons in argon plasma under the abovementioned thermodynamic condition. A simplified and self-consistent method to deduce the reflectivity R(λ) at the baseplate surface is applied. It demonstrates that the values of R(λ) are all around 0.4 in the experiments, which are basically in agreement with those given by Erskine previously (1994 J. Quant. Spectrosc. Radiat.Transfer 51 97).

  7. 21 CFR 868.1075 - Argon gas analyzer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Argon gas analyzer. 868.1075 Section 868.1075 Food... DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1075 Argon gas analyzer. (a) Identification. An argon gas analyzer is a device intended to measure the concentration of argon in a gas mixture to aid...

  8. Negative corona current pulses in argon and in mixture argon with SF6

    International Nuclear Information System (INIS)

    Waveforms of the first negative current pulses in a short negative point-to plane gap in pure argon and argon with SF6 admixture have been investigated with a nanosecond time resolution at a gas pressure 50 kPa as a function of applied gap voltage and content of SF6 in the mixture. We have made an attempt to explain the differences in the discharge development in pure argon and in argon with admixture of SF6 based on the observed changes of the pulse shape. The experimental results obtained will be discussed in context with existing computer simulation models (Authors)

  9. Separation of seven arsenic compounds by high-performance liquid chromatography with on-line detection by hydrogen–argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, S. H.; Larsen, E. H.; Pritzl, G.;

    1992-01-01

    of mixtures of arsenic standards into the HPLC system were: arsenite, As(III) 1.1; arsenate, As(V) 1.4; MMA 1.4; DMA 0.7; AsB 0.3; AsC 0.5; and the TMAs 0.4. The HPLC-AAS system was used for the analysis of arsenic species in aqueous extracts of soil samples from a polluted land site. Only arsenate was found......Seven molecular forms of arsenic were separated by anion- and cation-exchange high-performance liquid chromatography (HPLC) with on-line detection by flame atomic absorption spectrometry (FAAS). The interfacing was established by a vented poly(tetrafluoroethylene) capillary tubing connecting...... the HPLC column to the nebulizer of the atomic absorption spectrometer. Arsenite, arsenate, monomethylarsonate (MMA) and dimethylarsinate (DMA) were separated from each other and from the co-injected cationic arsenic compounds, arsenobetaine (AsB), arsenocholine (AsC) and the tetramethylarsonium ion (TMAs...

  10. Separation of seven arsenic compounds by high performance liquid chromatography with on-line detection by hydrogen-argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, S. H.; Larsen, Erik Huusfeldt; Pritzl, G.;

    1992-01-01

    of mixtures of arsenic standards into the HPLC system were: arsenite, As(III) 1.1; arsenate, As(V) 1.4; MMA 1.4; DMA 0.7; AsB 0.3; AsC 0.5; and the TMAs 0.4. The HPLC-AAS system was used for the analysis of arsenic species in aqueous extracts of soil samples from a polluted land site. Only arsenate was found......Seven molecular forms of arsenic were separated by anion- and cation-exchange high-performance liquid chromatography (HPLC) with on-line detection by flame atomic absorption spectrometry (FAAS). The interfacing was established by a vented poly(tetrafluoroethylene) capillary tubing connecting...... the HPLC column to the nebulizer of the atomic absorption spectrometer. Arsenite, arsenate, monomethylarsonate (MMA) and dimethylarsinate (DMA) were separated from each other and from the co-injected cationic arsenic compounds, arsenobetaine (AsB), arsenocholine (AsC) and the tetramethylarsonium ion (TMAs...

  11. LArGe: active background suppression using argon scintillation for the GERDA 0νββ-experiment

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, M.; Budjas, D.; Schoenert, S. [Technische Universitaet Muenchen, Munich (Germany); Barnabe-Heider, M. [Technische Universitaet Muenchen, Munich (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Cattadori, C. [Universita degli Studi di Milano, Milan (Italy); INFN, Milan (Italy); Gangapshev, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Institut for Nuclear Research, Moscow (Russian Federation); Gusev, K. [Technische Universitaet Muenchen, Munich (Germany); Joint Institut for Nuclear Research, Dubna (Russian Federation); National Research Center Kurchatov Institut, Moscow (Russian Federation); Heisel, M.; Smolnikov, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Junker, M. [Laboratori Nazionali del Gran Sasso, Assergi (Italy); Klimenko, A.; Lubashevskiy, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Joint Institut for Nuclear Research, Dubna (Russian Federation); Pelczar, K. [Jagellonian University, Cracow (Poland); Zuzel, G. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Jagellonian University, Cracow (Poland)

    2015-10-15

    LArGe is a GERDA low-background test facility to study novel background suppression methods in a low-background environment, for future application in the GERDA experiment. Similar to GERDA, LArGe operates bare germanium detectors submersed into liquid argon (1 m{sup 3}, 1.4tons), which in addition is instrumented with photomultipliers to detect argon scintillation light. The scintillation signals are used in anti-coincidence with the germanium detectors to effectively suppress background events that deposit energy in the liquid argon. The background suppression efficiency was studied in combination with a pulse shape discrimination (PSD) technique using a BEGe detector for various sources, which represent characteristic backgrounds to GERDA. Suppression factors of a few times 10{sup 3} have been achieved. First background data of LArGe with a coaxial HPGe detector (without PSD) yield a background index of (0.12 - 4.6) x 10{sup -2} cts/(keV kg year) (90 % C.L.), which is at the level of GERDA Phase I. Furthermore, for the first time we monitor the natural {sup 42}Ar abundance (parallel to GERDA), and have indication for the 2νββ-decay in natural germanium. These results show the effectivity of an active liquid argon veto in an ultra-low background environment. As a consequence, the implementation of a liquid argon veto in GERDA Phase II is pursued. (orig.)

  12. LArGe: active background suppression using argon scintillation for the Gerda 0ν β β -experiment

    Science.gov (United States)

    Agostini, M.; Barnabé-Heider, M.; Budjáš, D.; Cattadori, C.; Gangapshev, A.; Gusev, K.; Heisel, M.; Junker, M.; Klimenko, A.; Lubashevskiy, A.; Pelczar, K.; Schönert, S.; Smolnikov, A.; Zuzel, G.

    2015-10-01

    LArGe is a Gerda low-background test facility to study novel background suppression methods in a low-background environment, for future application in the Gerda experiment. Similar to Gerda, LArGe operates bare germanium detectors submersed into liquid argon (1 m^3, 1.4 tons), which in addition is instrumented with photomultipliers to detect argon scintillation light. The scintillation signals are used in anti-coincidence with the germanium detectors to effectively suppress background events that deposit energy in the liquid argon. The background suppression efficiency was studied in combination with a pulse shape discrimination (PSD) technique using a BEGe detector for various sources, which represent characteristic backgrounds to Gerda. Suppression factors of a few times 10^3 have been achieved. First background data of LArGe with a coaxial HPGe detector (without PSD) yield a background index of (0.12-4.6)× 10^{-2} cts/(keV kg year) (90 % C.L.), which is at the level of Gerda Phase I. Furthermore, for the first time we monitor the natural ^{42}Ar abundance (parallel to Gerda), and have indication for the 2ν β β -decay in natural germanium. These results show the effectivity of an active liquid argon veto in an ultra-low background environment. As a consequence, the implementation of a liquid argon veto in Gerda Phase II is pursued.

  13. LArGe: active background suppression using argon scintillation for the GERDA 0νββ-experiment

    International Nuclear Information System (INIS)

    LArGe is a GERDA low-background test facility to study novel background suppression methods in a low-background environment, for future application in the GERDA experiment. Similar to GERDA, LArGe operates bare germanium detectors submersed into liquid argon (1 m3, 1.4tons), which in addition is instrumented with photomultipliers to detect argon scintillation light. The scintillation signals are used in anti-coincidence with the germanium detectors to effectively suppress background events that deposit energy in the liquid argon. The background suppression efficiency was studied in combination with a pulse shape discrimination (PSD) technique using a BEGe detector for various sources, which represent characteristic backgrounds to GERDA. Suppression factors of a few times 103 have been achieved. First background data of LArGe with a coaxial HPGe detector (without PSD) yield a background index of (0.12 - 4.6) x 10-2 cts/(keV kg year) (90 % C.L.), which is at the level of GERDA Phase I. Furthermore, for the first time we monitor the natural 42Ar abundance (parallel to GERDA), and have indication for the 2νββ-decay in natural germanium. These results show the effectivity of an active liquid argon veto in an ultra-low background environment. As a consequence, the implementation of a liquid argon veto in GERDA Phase II is pursued. (orig.)

  14. Potassium-argon/argon-40-argon-39 geochronology of Cenozoic alkali basalts from the South China Sea

    Institute of Scientific and Technical Information of China (English)

    YAN Quanshu; SHI Xuefa; YANG Yaomin; WANG Kunshan

    2008-01-01

    Based on the isotopic chronologic results of Cenozoic alkali basalts from the South China Sea,the characteristics of volcanic activi-ty of the South China Sea after spreading were studied.The potassium - argon ages of eight alkali basalt samples from the South China Sea,and the argon - argon ages of two samples among them are reported.Apparent ages of the whole rock are 3.80 to 7.91 Ma with an average value of 5.43 Ma (potassium- argon,whole rock),and there is little difference among samples at the same location,e.g.,4.76~5.78 Ma for location S04-12.The argon - argon ages for the two samples are 6.06 and 4.71 Ma,which lie within the age scope of potassium - argon method.The dating results indicate that rock-forming age is from late Miocene to Pli-ocene,which is consistent with erupting event for alkali basalts from adjacent regions of the South China Sea.Volcanic activities occur after the cessation of spreading of the South China Sea,which are controlled by lithospheric fault and the spreading center formed during the spreading period of the South China Sea.These dating results,combined with geochemical characteristics of these basalts,the published chronological data for the South China Sea and its adjacent regions,and the updated geophysical data near Hainan Island,suggest that after the cessation of spreading of the South China Sea,there occur widely distributing magmatic activities which primarily is alkali basalt,and the volcanic activity continues to Quaternary.The activity may be relative to Hainan mantle plume originated from core/mantle boundary.

  15. Ionic Wind Phenomenon and Charge Carrier Mobility in Very High Density Argon Corona Discharge Plasma

    Science.gov (United States)

    Nur, M.; Bonifaci, N.; Denat, A.

    2014-04-01

    Wind ions phenomenon has been observed in the high density argon corona discharge plasma. Corona discharge plasma was produced by point to plane electrodes and high voltage DC. Light emission from the recombination process was observed visually. The light emission proper follow the electric field lines that occur between point and plane electrodes. By using saturation current, the mobilities of non-thermal electrons and ions have been obtained in argon gas and liquid with variation of density from 2,5 1021 to 2 1022 cm-3. In the case of ions, we found that the behaviour of the apparent mobility inversely proportional to the density or follow the Langevin variation law. For non-thermal electron, mobility decreases and approximately follows a variation of Langevin type until the density <= 0,25 the critical density of argon.

  16. Argon Collection And Purification For Proliferation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Achey, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hunter, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-09

    In order to determine whether a seismic event was a declared/undeclared underground nuclear weapon test, environmental samples must be taken and analyzed for signatures that are unique to a nuclear explosion. These signatures are either particles or gases. Particle samples are routinely taken and analyzed under the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) verification regime as well as by individual countries. Gas samples are analyzed for signature gases, especially radioactive xenon. Underground nuclear tests also produce radioactive argon, but that signature is not well monitored. A radioactive argon signature, along with other signatures, can more conclusively determine whether an event was a nuclear test. This project has developed capabilities for collecting and purifying argon samples for ultra-low-background proportional counting. SRNL has developed a continuous gas enrichment system that produces an output stream containing 97% argon from whole air using adsorbent separation technology (the flow diagram for the system is shown in the figure). The vacuum swing adsorption (VSA) enrichment system is easily scalable to produce ten liters or more of 97% argon within twelve hours. A gas chromatographic separation using a column of modified hydrogen mordenite molecular sieve has been developed that can further purify the sample to better than 99% purity after separation from the helium carrier gas. The combination of these concentration and purification systems has the capability of being used for a field-deployable system for collecting argon samples suitable for ultra-low-background proportional counting for detecting nuclear detonations under the On-Site Inspection program of the CTBTO verification regime. The technology also has applications for the bulk argon separation from air for industrial purposes such as the semi-conductor industry.

  17. Kinetic and experimental study of argon and argon--nitrogen mixtures excited by fission fragments

    International Nuclear Information System (INIS)

    Optical emission from argon and argon-nitrogen mixtures excited by fission fragments are studied in an effort to better understand the fission fragment energy deposition into the gas. A model of the energy flow in the gas is developed and compared with the experimental results

  18. ATLAS Recordings

    CERN Multimedia

    Jeremy Herr; Homer A. Neal; Mitch McLachlan

    The University of Michigan Web Archives for the 2006 ATLAS Week Plenary Sessions, as well as the first of 2007, are now online. In addition, there are a wide variety of Software and Physics Tutorial sessions, recorded over the past couple years, to chose from. All ATLAS-specific archives are accessible here.Viewing requires a standard web browser with RealPlayer plug-in (included in most browsers automatically) and works on any major platform. Lectures can be viewed directly over the web or downloaded locally.In addition, you will find access to a variety of general tutorials and events via the portal. Shaping Collaboration 2006The Michigan group is happy to announce a complete set of recordings from the Shaping Collaboration conference held last December at the CICG in Geneva.The event hosted a mix of Collaborative Tool experts and LHC Users, and featured presentations by the CERN Deputy Director General, Prof. Jos Engelen, the President of Internet2, and chief developers from VRVS/EVO, WLAP, and other tools...

  19. Argon activation analysis, application to dating by the potassium-argon method

    International Nuclear Information System (INIS)

    Activation analysis using radiogenic argon-40 has been applied to rock-dating by the K-Ar method. The argon is extracted from the sample, purified, activated to saturation in a flux of 2 X 1013 neutrons/cm2 sec-1 and measured by gamma spectroscopy. The sensitivity obtained is such that it is possible to measure amounts of argon corresponding to age of a few thousand years only. However since it has not been possible to measure the amount of pollution of radiogenic argon by atmospheric argon with any accuracy, the measurable age limit is in fact of the order of MY. The method has been applied to basalts from the Mont-Dore region. The results obtained are in fairly good agreement with geological, stratigraphic and paleomagnetic data. (author)

  20. Electroweak Physics with ATLAS

    OpenAIRE

    Akhundov, Arif

    2008-01-01

    The precision measurements of electroweak parameters of the Standard Model with the ATLAS detector at LHC are reviewed. An emphasis is put on the bridge connecting the ATLAS measurements with the SM analysis at LEP/SLC and the Tevatron.

  1. Search for magnetic monopoles in 8 TeV centre-of-mass energy proton-proton collisions with the ATLAS detector at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00237152

    Symmetry is fundamental to our understanding of the laws of nature. The simplicity that is found in the symmetries that explain the most fundamental interactions is remarkably beautiful. Physicists have worked hard and continue to work even harder to deepen the understanding of nature with the hope of revealing higher symmetries, among them the symmetry between electricity and magnetism, but one piece is still missing from this puzzle: the elusive magnetic monopole. This dissertation presents a search for magnetic monopoles produced at the Large Hadron Collider in 8 TeV centre-of-mass energy proton–proton collisions using the ATLAS detector. The highly ionizing nature of monopoles was exploited to look for regions of high ionization density in the Transition Radiation Tracker and energy deposits in the Liquid-Argon electromagnetic calorimeter with very low lateral dispersion. The search used 7 fb$^{−1}$ of data collected by a dedicated trigger for highly ionizing particles, which made the ATLAS detector s...

  2. Atlases: Complex models of geospace

    Directory of Open Access Journals (Sweden)

    Ikonović Vesna

    2005-01-01

    Full Text Available Atlas is modeled contexture contents of treated thematic of space on optimal map union. Atlases are higher form of cartography. Atlases content composition of maps which are different by projection, scale, format methods, contents, usage and so. Atlases can be classified by multi criteria. Modern classification of atlases by technology of making would be on: 1. classical or traditional (printed on paper and 2. electronic (made on electronic media - computer or computer station. Electronic atlases divided in three large groups: view-only electronic atlases, 2. interactive electronic atlases and 3. analytical electronic atlases.

  3. ATLAS LAr calorimeter performance and LHC Run-2 commissioning

    Science.gov (United States)

    Spettel, Fabian

    2016-07-01

    The ATLAS detector was built to study proton-proton collisions produced by the Large Hadron Collider (LHC) at a center of mass energy of up to 14 TeV. The Liquid Argon (LAr) calorimeters are used for all electromagnetic calorimetry as well as the hadronic calorimetry in the endcap and forward regions. They have shown excellent performance during the first LHC data taking campaign, from 2010 to 2012, so-called Run 1, at a peak luminosity of 8 ×1033cm-2s-1. During the next run, peak luminosities of 1.5 ×1034cm-2s-1 and even higher are expected at a 25 ns bunch spacing. Such a high collision rate may have an impact on the quality of the energy reconstruction which is attempted to be maintained at a high level using a calibration procedure described in this contribution. It also poses major challenges to the first level of the trigger system which is constrained to a maximal rate of 100 kHz. For Run-3, scheduled to start in 2019, instantaneous luminosity as high as 3 ×1034cm-2s-1 are foreseen imposing an upgrade of the LAr trigger system to maintain its performance. A demonstrator containing prototypes of the upgraded trigger electronic architecture has been installed on one of the barrel electromagnetic calorimeter readout front end crates to test it during the Run-2 campaign. The new architecture and its benefits for data taking will be discussed below as well as the results from first beam splash events.

  4. EnviroAtlas - Phoenix, AZ - Atlas Area Boundary

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the boundary of the Phoenix, AZ Atlas Area. It represents the outside edge of all the block groups included in the EnviroAtlas Area....

  5. EnviroAtlas - Portland, OR - Atlas Area Boundary

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the boundary of the Portland, OR Atlas Area. It represents the outside edge of all the block groups included in the EnviroAtlas Area....

  6. Upgraded Trigger Readout Electronics for the ATLAS LAr Calorimeters for Future LHC Running

    CERN Document Server

    Ma, H; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that are digitized and processed by the front-end and back-end electronics for every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first- level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34cm^−2s^−1. In order to retain the capability to trigger on low energy electrons and photons when the LHC is upgraded to higher luminosity, an improved LAr calorimeter trigger readout is proposed and being constructed. The new trigger readout system makes available the fine segmentation of the calorimeter at the L1 trigger with high precision in order to reduce the QCD jet background in electron, photon and tau triggers, and to improve jet and missing ET trigger performance. The new LAr Trigger Digitizer Board is designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a...

  7. FELIX: A high-throughput network approach for interfacing to front end electronics for ATLAS upgrades

    CERN Document Server

    Anderson, John Thomas; The ATLAS collaboration; Boterenbrood, Hendrik; Chen, Hucheng; Chen, Kai; Drake, Gary; Francis, David; Gorini, Benedetto; Lanni, Francesco; Lehmann Miotto, Giovanna; Levinson, Lorne; Narevicius, Julia; Christian Plessl; Roich, Alexander; Schreuder, Frans Philip; Schumacher, Jorn; Vandelli, Wainer; Vermeulen, Jos; Zhang, Jinlong

    2015-01-01

    The ATLAS experiment at CERN is planning full deployment of a new unified link technology for connecting detector front end electronics on the timescale of the LHC Run 4 (2025). It is estimated that roughly 8000 GBT (GigaBit Transceiver) links, with transfer rates probably up to 9.6 Gbps, will replace existing links used for readout, detector control and distribution of timing and trigger information. In particular the links used for readout are often detector-specific. Already in Run 3 this technology will be deployed in conjunction with new muon detectors, additional muon first-level triggering electronics and new on-detector and off-detector liquid argon calorimeter electronics to be used for first level triggering. A total of roughly 2000 GBT links or GBT-like links (for connecting to off-detector trigger electronics) will be needed. A new class of devices will need to be developed to interface many GBT links to the rest of the trigger, data-acquisition and detector control systems. In this paper we prese...

  8. Hadron energy reconstruction for the ATLAS calorimetry in the framework of the nonparametrical method

    CERN Document Server

    Akhmadaliev, S Z; Ambrosini, G; Amorim, A; Anderson, K; Andrieux, M L; Aubert, Bernard; Augé, E; Badaud, F; Baisin, L; Barreiro, F; Battistoni, G; Bazan, A; Bazizi, K; Belymam, A; Benchekroun, D; Berglund, S R; Berset, J C; Blanchot, G; Bogush, A A; Bohm, C; Boldea, V; Bonivento, W; Bosman, M; Bouhemaid, N; Breton, D; Brette, P; Bromberg, C; Budagov, Yu A; Burdin, S V; Calôba, L P; Camarena, F; Camin, D V; Canton, B; Caprini, M; Carvalho, J; Casado, M P; Castillo, M V; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Chadelas, R; Chalifour, M; Chekhtman, A; Chevalley, J L; Chirikov-Zorin, I E; Chlachidze, G; Citterio, M; Cleland, W E; Clément, C; Cobal, M; Cogswell, F; Colas, Jacques; Collot, J; Cologna, S; Constantinescu, S; Costa, G; Costanzo, D; Crouau, M; Daudon, F; David, J; David, M; Davidek, T; Dawson, J; De, K; de La Taille, C; Del Peso, J; Del Prete, T; de Saintignon, P; Di Girolamo, B; Dinkespiler, B; Dita, S; Dodd, J; Dolejsi, J; Dolezal, Z; Downing, R; Dugne, J J; Dzahini, D; Efthymiopoulos, I; Errede, D; Errede, S; Evans, H; Eynard, G; Fassi, F; Fassnacht, P; Ferrari, A; Ferrer, A; Flaminio, Vincenzo; Fournier, D; Fumagalli, G; Gallas, E; Gaspar, M; Giakoumopoulou, V; Gianotti, F; Gildemeister, O; Giokaris, N; Glagolev, V; Glebov, V Yu; Gomes, A; González, V; González de la Hoz, S; Grabskii, V; Graugès-Pous, E; Grenier, P; Hakopian, H H; Haney, M; Hébrard, C; Henriques, A; Hervás, L; Higón, E; Holmgren, Sven Olof; Hostachy, J Y; Hoummada, A; Huston, J; Imbault, D; Ivanyushenkov, Yu M; Jézéquel, S; Johansson, E K; Jon-And, K; Jones, R; Juste, A; Kakurin, S; Karyukhin, A N; Khokhlov, Yu A; Khubua, J I; Klioukhine, V I; Kolachev, G M; Kopikov, S V; Kostrikov, M E; Kozlov, V; Krivkova, P; Kukhtin, V V; Kulagin, M; Kulchitskii, Yu A; Kuzmin, M V; Labarga, L; Laborie, G; Lacour, D; Laforge, B; Lami, S; Lapin, V; Le Dortz, O; Lefebvre, M; Le Flour, T; Leitner, R; Leltchouk, M; Li, J; Liablin, M V; Linossier, O; Lissauer, D; Lobkowicz, F; Lokajícek, M; Lomakin, Yu F; López-Amengual, J M; Lund-Jensen, B; Maio, A; Makowiecki, D S; Malyukov, S N; Mandelli, L; Mansoulié, B; Mapelli, Livio P; Marin, C P; Marrocchesi, P S; Marroquim, F; Martin, P; Maslennikov, A L; Massol, N; Mataix, L; Mazzanti, M; Mazzoni, E; Merritt, F S; Michel, B; Miller, R; Minashvili, I A; Miralles, L; Mnatzakanian, E A; Monnier, E; Montarou, G; Mornacchi, Giuseppe; Moynot, M; Muanza, G S; Nayman, P; Némécek, S; Nessi, Marzio; Nicoleau, S; Niculescu, M; Noppe, J M; Onofre, A; Pallin, D; Pantea, D; Paoletti, R; Park, I C; Parrour, G; Parsons, J; Pereira, A; Perini, L; Perlas, J A; Perrodo, P; Pilcher, J E; Pinhão, J; Plothow-Besch, Hartmute; Poggioli, Luc; Poirot, S; Price, L; Protopopov, Yu; Proudfoot, J; Puzo, P; Radeka, V; Rahm, David Charles; Reinmuth, G; Renzoni, G; Rescia, S; Resconi, S; Richards, R; Richer, J P; Roda, C; Rodier, S; Roldán, J; Romance, J B; Romanov, V; Romero, P; Rossel, F; Rusakovitch, N A; Sala, P; Sanchis, E; Sanders, H; Santoni, C; Santos, J; Sauvage, D; Sauvage, G; Sawyer, L; Says, L P; Schaffer, A C; Schwemling, P; Schwindling, J; Seguin-Moreau, N; Seidl, W; Seixas, J M; Selldén, B; Seman, M; Semenov, A; Serin, L; Shaldaev, E; Shochet, M J; Sidorov, V; Silva, J; Simaitis, V J; Simion, S; Sissakian, A N; Snopkov, R; Söderqvist, J; Solodkov, A A; Soloviev, A; Soloviev, I V; Sonderegger, P; Soustruznik, K; Spanó, F; Spiwoks, R; Stanek, R; Starchenko, E A; Stavina, P; Stephens, R; Suk, M; Surkov, A; Sykora, I; Takai, H; Tang, F; Tardell, S; Tartarelli, F; Tas, P; Teiger, J; Thaler, J; Thion, J; Tikhonov, Yu A; Tisserant, S; Tokar, S; Topilin, N D; Trka, Z; Turcotte, M; Valkár, S; Varanda, M J; Vartapetian, A H; Vazeille, F; Vichou, I; Vinogradov, V; Vorozhtsov, S B; Vuillemin, V; White, A; Wielers, M; Wingerter-Seez, I; Wolters, H; Yamdagni, N; Yosef, C; Zaitsev, A; Zitoun, R; Zolnierowski, Y

    2002-01-01

    This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the nonparametrical method. The nonparametrical method utilizes only the known e/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within +or-1% of the true values and the fractional energy resolution is [(58+or-3)%/ square root E+(2.5+or-0.3)%](+)(1.7+or-0.2)/E. The value of the e/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74+or-0.04 and agrees with the prediction that e/h >1.66 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam...

  9. Performance of the ATLAS Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    Burghgrave, Blake; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the Large Hadron Collider (LHC) is equipped with electromagnetic and hadronic liquid-argon (LAr) calorimeters and a hadronic scintillator-steel sampling calorimeter (TileCal) for measuring energy and direction of final state particles in the pseudorapidity range |η|<4.9. The calibration and performance of the calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb−1 of data have been collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~fb−1 of data at a center-of-mass energy of 13~TeV recorded in this year. Results on the calorimeter operation, monitoring and data quality, as well as their performance will be presented, including the calibration and stability of the electromagnetic scale, response uniformit...

  10. Energy Measurement with the ATLAS Electromagnetic Calorimeter at the Per Mill Accuracy Level

    CERN Document Server

    Teischinger, Florian; Fabjan, Christian

    The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider (LHC) at CERN. It is made up of various sub-detectors to measure the properties of all the particles produced at the proton-proton collision. Over the last three years of running around 20 x 10^14 collisions of proton data have been recorded. Liquid argon (LAr) sampling calorimeters are used for all electromagnetic calorimetry and for hadronic calorimetry in the end-caps. The Inner Detector, on the other hand, measures the transverse momentum of charged particles down to a momentum of 0.5 GeV. This thesis deals with the absolute measurement of the energy in the electromagnetic calorimeter and the improvement of the systematic uncertainties. A method using the ratio of the energy E in the calorimeter and the momentum measurement p in the Inner Detector (E/p) was used to extract the energy scale of the electromagnetic LAr calorimeter for electrons and positrons. To investigate and further reduce the syst...

  11. Upgraded Trigger Readout Electronics for the ATLAS LAr Calorimeters for Future LHC Running

    International Nuclear Information System (INIS)

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that are digitized and processed by the front-end and back-end electronics for every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first- level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 1034cm−2s−1. In order to retain the capability to trigger on low energy electrons and photons when the LHC is upgraded to higher luminosity, an improved LAr calorimeter trigger readout is proposed and being constructed. The new trigger readout system makes available the fine segmentation of the calorimeter at the L1 trigger with high precision in order to reduce the QCD jet background in electron, photon and tau triggers, and to improve jet and missing ET trigger performance. The new LAr Trigger Digitizer Board is designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new Digital Processing System. The reconstructed energies of trigger readout channels after digital filtering are transmitted to the L1 system, allowing the extraction of improved trigger signatures. This contribution presents the motivation for the upgrade, the concept for the new trigger readout and the expected performance of the new trigger, and describes the components being developed for the new system

  12. ATLAS Distributed Computing Automation

    CERN Document Server

    Schovancova, J; The ATLAS collaboration; Borrego, C; Campana, S; Di Girolamo, A; Elmsheuser, J; Hejbal, J; Kouba, T; Legger, F; Magradze, E; Medrano Llamas, R; Negri, G; Rinaldi, L; Sciacca, G; Serfon, C; Van Der Ster, D C

    2012-01-01

    The ATLAS Experiment benefits from computing resources distributed worldwide at more than 100 WLCG sites. The ATLAS Grid sites provide over 100k CPU job slots, over 100 PB of storage space on disk or tape. Monitoring of status of such a complex infrastructure is essential. The ATLAS Grid infrastructure is monitored 24/7 by two teams of shifters distributed world-wide, by the ATLAS Distributed Computing experts, and by site administrators. In this paper we summarize automation efforts performed within the ATLAS Distributed Computing team in order to reduce manpower costs and improve the reliability of the system. Different aspects of the automation process are described: from the ATLAS Grid site topology provided by the ATLAS Grid Information System, via automatic site testing by the HammerCloud, to automatic exclusion from production or analysis activities.

  13. Two-phase Cryogenic Avalanche Detector with electroluminescence gap operated in argon doped with nitrogen

    CERN Document Server

    Bondar, A; Dolgov, A; Nosov, V; Shekhtman, L; Shemyakina, E; Sokolov, A

    2016-01-01

    A two-phase Cryogenic Avalanche Detector (CRAD) with electroluminescence (EL) gap, operated in argon doped with a minor (49$\\pm$7 ppm) admixture of nitrogen, has been studied. The EL gap was optically read out using cryogenic PMTs located on the perimeter of the gap. We present the results of the measurements of the N$_2$ content, detector sensitivity to X-ray-induced signals, EL gap yield and electron lifetime in the liquid. The detector sensitivity, at a drift field in liquid Ar of 0.6 kV/cm, was measured to be 9 and 16 photoelectrons recorded at the PMTs per keV of deposited energy at 23 and 88 keV respectively. Such two-phase detectors, with enhanced sensitivity to the S2 (ionization-induced) signal, are relevant in the field of argon detectors for dark matter search and low energy neutrino detection.

  14. Contraction ionization waves in the argon contracted discharge

    International Nuclear Information System (INIS)

    An investigation of ionization waves in the argon contracted discharge and a definition of their arising propagation mechanism accounting for the specificity of elementary pocesses characteristic of argon are presented. (author)

  15. Thermal decomposition of barium valerate in argon

    DEFF Research Database (Denmark)

    Torres, P.; Norby, Poul; Grivel, Jean-Claude

    2015-01-01

    The thermal decomposition of barium valerate (Ba(C4H9CO2)(2)/Ba-pentanoate) was studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage optical microscopy. Melting takes place in two different steps, at 200 degrees C and 280...

  16. Antiapoptotic activity of argon and xenon.

    Science.gov (United States)

    Spaggiari, Sabrina; Kepp, Oliver; Rello-Varona, Santiago; Chaba, Kariman; Adjemian, Sandy; Pype, Jan; Galluzzi, Lorenzo; Lemaire, Marc; Kroemer, Guido

    2013-08-15

    Although chemically non-reactive, inert noble gases may influence multiple physiological and pathological processes via hitherto uncharacterized physical effects. Here we report a cell-based detection system for assessing the effects of pre-defined gas mixtures on the induction of apoptotic cell death. In this setting, the conventional atmosphere for cell culture was substituted with gas combinations, including the same amount of oxygen (20%) and carbon dioxide (5%) but 75% helium, neon, argon, krypton, or xenon instead of nitrogen. The replacement of nitrogen with noble gases per se had no effects on the viability of cultured human osteosarcoma cells in vitro. Conversely, argon and xenon (but not helium, neon, and krypton) significantly limited cell loss induced by the broad-spectrum tyrosine kinase inhibitor staurosporine, the DNA-damaging agent mitoxantrone and several mitochondrial toxins. Such cytoprotective effects were coupled to the maintenance of mitochondrial integrity, as demonstrated by means of a mitochondrial transmembrane potential-sensitive dye and by assessing the release of cytochrome c into the cytosol. In line with this notion, argon and xenon inhibited the apoptotic activation of caspase-3, as determined by immunofluorescence microscopy coupled to automated image analysis. The antiapoptotic activity of argon and xenon may explain their clinically relevant cytoprotective effects. PMID:23907115

  17. Argon-ion contamination of the plasmasphere

    International Nuclear Information System (INIS)

    This paper applies present observational and analytic knowledge on effects of plasma beam interaction wth the magnetosphere to the plasmasphere contamination problem of the argon ion engine exhaust expected to be deposited in the magnetosphere during the construction phase of the Satellite Power System. Effects of plasmasphere, ionosphere, and radiation belt modifications are discussed

  18. Silicon compounds of neon and argon

    Czech Academy of Sciences Publication Activity Database

    Roithová, J.; Schröder, Detlef

    -, č. 46 (2009), s. 8788-8790. ISSN 1433-7851 R&D Projects: GA ČR GA203/09/1223 Grant ostatní: ERC(XE) Adg HORIZOMS Institutional research plan: CEZ:AV0Z40550506 Keywords : argon * bond formation * dications * neon Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 11.829, year: 2009

  19. Argon Laser Treatment of Strawberry Hemangioma in Infancy

    OpenAIRE

    Achauer, Bruce M.; Vander Kam, Victoria M.

    1985-01-01

    Argon laser therapy is effective for removing port-wine stains and for reducing cutaneous vascular and pigmented lesions. Strawberry hemangiomas, being much thicker lesions than port-wine stains, were considered not appropriate for argon laser treatment. Using argon laser therapy in 13 cases of strawberry hemangioma, we achieved poor to dramatic results.

  20. Common versus noble Bacillus subtilis differentially responds to air and argon gas plasma.

    Science.gov (United States)

    Winter, Theresa; Bernhardt, Jörg; Winter, Jörn; Mäder, Ulrike; Schlüter, Rabea; Weltmann, Klaus-Dieter; Hecker, Michael; Kusch, Harald

    2013-09-01

    The applications of low-temperature plasma are not only confined to decontamination and sterilization but are also found in the medical field in terms of wound and skin treatment. For the improvement of already established and also for new plasma techniques, in-depth knowledge on the interactions between plasma and microorganism is essential. In an initial study, the interaction between growing Bacillus subtilis and argon plasma was investigated by using a growth chamber system suitable for low-temperature gas plasma treatment of bacteria in liquid medium. In this follow-up investigation, a second kind of plasma treatment-namely air plasma-was applied. With combined proteomic and transcriptomic analyses, we were able to investigate the plasma-specific stress response of B. subtilis toward not only argon but also air plasma. Besides an overlap of cellular responses due to both argon and air plasma treatment (DNA damage and oxidative stress), a variety of gas-dependent cellular responses such as growth retardation and morphological changes were observed. Only argon plasma treatments lead to a phosphate starvation response whereas air plasma induced the tryptophan operon implying damage by photooxidation. Biological findings were supported by the detection of reactive plasma species by optical emission spectroscopy and Fourier transformed infrared spectroscopy measurements. PMID:23794223