ICARUS at FNAL: a proposal. Carlo Rubbia, GSSI INFN, Italy

Transcription

1 ICARUS at FNAL: a proposal Carlo Rubbia, GSSI INFN, Italy PAC_FNAL 23 January

2 The ICARUS Collaboration M. Antonello 1, B. Baibussinov 2, V. Bellini 4,5, H. Bilokon 6, F. Boffelli 7, M. Bonesini 9, E. Calligarich 8, S. Centro 2,3, K. Cieslik 10, D. B. Cline 11, A. G. Cocco 12, A. Curioni 9, A. Dermenev 13, R. Dolfini 7,8, A. Falcone 7,8, C. Farnese 2, A. Fava 3, A. Ferrari 14, D. Gibin 2,3, S. Gninenko 13, F. Guber 13, A. Guglielmi 2, M. Haranczyk 10, J. Holeczek 15, A. Ivashkin 13, M. Kirsanov 13, J. Kisiel 15, I. Kochanek 15, A. Kurepin 13, J. Łagoda 16, F. Mammoliti 4, S. Mania 15, G. Mannocchi 6, V. Matveev 13, A. Menegolli 7,8, G. Meng 2, G. B. Mills 17, C. Montanari 8, F. Noto 4, S. Otwinowski 11, T. J. Palczewski 16, P. Picchi 6, F. Pietropaolo 2, P. Płonśki 18, R. Potenza 4,5, A. Rappoldi 8, G. L. Raselli 8, M. Rossella 8, C. Rubbia 19,14,a, P. Sala 20, A. Scaramelli 20, E. Segreto 1, D. Stefan 1, J. Stepaniak 16, R. Sulej 16, C. M. Sutera 4, D. Tlisov 13, M. Torti 7,8, R. G. Van de Water 17, F. Varanini 3, S. Ventura 2, C. Vignoli 1, H. G. Wang 11, X. Yang 11, A. Zani 7,8, K. Zaremba 18 INFN, LNGS, Assergi (AQ), Italy 1), INFN, Sezione di Padova, Padova, Italy 2), Dipartimento di Fisica, Università di Padova, Padova, Italy 3), INFN, Sezione di Catania, Catania, Italy 5), INFN, Laboratori Nazionali di Frascati (LNF), Frascati (Roma), Italy 6), Dipartimento di Fisica, Università di Pavia, Pavia, Italy 7), INFN, Sezione di Pavia, Pavia, Italy 8), INFN, Sezione di Milano Bicocca, Dipartimento di Fisica G. Occhialini, Milano, Italy 9), The H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Science, Kraków, Poland 10), Department of Physics and Astronomy, University of California, Los Angeles, USA 11), INFN, Sezione di Napoli, Dipartimento di Scienze Fisiche, Università Federico II, Napoli, Italy 12), INR-RAS, Moscow, Russia 13), CERN, Geneva, Switzerland 14), Institute of Physics, University of Silesia, Katowice, Poland 15), National Center for Nuclear Research, Warszawa, Poland 16), Los Alamos National Laboratory, New Mexico, USA 17), Institute for Radioelectronics, Warsaw University of Technology, Warsaw, Poland 18), GSSI, L Aquila (AQ), Italy 19), INFN, Sezione di Milano, Milano, Italy 20) PAC_FNAL 23 January 2014 Slide: 2

3 Bringing the LAr TPC technology to a success PAC_FNAL 23 January 2014 Slide: 3 The Italian Istituto Nazionale di Fisica Nucleare (INFN) and the ICARUS program have originally developed the technology of the LAr-TPC. Exposed in the underground Hall B of the Gran Sasso National Laboratory in Assergi, at 730 km to the neutrino beam from CERN, the ICARUS T600 neutrino experiment has now successfully completed a three years physics program at CNGS. The peer reviewed scientific publications of the collaboration on the LAr-TPC physics have today reached a total of 108 papers. From October 2010 to December 2012, over 3000 neutrino events have been collected in a physics program on a high energy ( 25 GeV) neutrino beam, corresponding to protons on target with an instrumental efficiency exceeding 93%. Additional data were also collected with cosmic rays and proton decay. Together with all previous test beam runs, this has allowed a very positive assessment of the detection capabilities of the LAr-TPC.

4 T600 at LNGS Hall B PAC_FNAL 23 January 2014 Slide: 4

5 N2 Phase separator LNGS: 0.77 kton LAr-TPC 30 m 3 Vessels for LN 2 cooling circuit N 2 liquefiers: 12 units, 48 kw total cryo-power Electronics ch. (54000 low noise charge amplifiers + digitizers, S/N > 10) LAr purification systems PAC_FNAL 23 January 2014 GAr purification systems Slide: Slide: 5

6 PAC_FNAL 23 January 2014 Slide: 6 A very elaborate cryogenic system The ICARUS purification system is very complex, and demands a continuous operation both in the liquid and gas phases Purification (2.5x/hour) of gas phase at the top (~40 Nm 3 ) Purification (100 m 3 /day) of the bulk liquid volume (~550 m 3 )

7 T600 LAr purity trend over 3 years Data taking with ele > 5 ms (60 p.p. trillion [O 2 ] eq ), with high speed recirculation both in gas (2.5 x/h) and liquid (in 5.5 days) 17% maximum charge attenuation at longest drift distance In the laboratory, a LAr lifetime of ele 21 ms has been attained corresponding to molecular Oxygen eq. impurities. New pump on East cryostat since April 4th, 2013! Gas phase alone is not sufficient to maintain purity PAC_FNAL 23 January 2014 Slide: 7

8 The potentialities of ICARUS at FNAL PAC_FNAL 23 January 2014 Slide: 19 On the basis of the wide experience of the T600 of several years, a number of substantial improvements will now be introduced. The R&D improvements are performed in a close collaboration with the LBNE experiment to which the six above INFN Institutions have become now participating members and in view of the presently described proposal for FNAL. During the next two years ICARUS will be moved to CERN. The present T600 detector (760 tons of ultra high purity LAr) will be complemented with a new, similar ¼ scale T150 detector. As a main novelty, a SC magnetic field of about 1 Tesla will be introduced inside the LAr volumes, in analogy to the performance of the traditional bubble chambers. A number of other main developments will be briefly described

9 PAC_FNAL 23 January 2014 Slide: 20 The ICARUS T600 as Far detector Components will be disassembled and transported to CERN: inner detectors, electronics, ancillary systems, LN 2 liquefaction system TPCs will be moved inside clean/lightweight containers like as for Pavia to LNGS transport. TPC s will be inserted in two new vessels of extruded Al, vacuum-tight < 10-5 mbar l s -1 standing up to 1 bar internal overpressure. New external insulation with better performance based on industrial membrane tank concept.

10 New T150 LAr-TPC The present T600 design is extended to T150 module (1/4 of T600): two readout chambers with 3 wire planes each, field shaping electrodes, a HV cathode between the two drift volumes. New light collection devices, with better efficiency, waveshifting and waveguides / reflectors can be implemented for both T150/T600 in order to increase the light collection efficiency and to operate in presence of magnetic field. Solid-state photo-detectors, such as Silicon Photomultipliers (SiPM) are to be envisaged as a possible alternative solution to the one of traditional PMTs. PAC_FNAL 23 January 2014 Slide: 21

11 PAC_FNAL 23 January 2014 Slide: 22 Detailed modelling of Al profiles to study the behaviour of cold body under several loading conditions and the assembly / welding procedures of Al profiles. New T600/T150 layout Warm cage + ext. skin Insulation +T600 modules Purely passive insulation chosen for T600/T150 installation, coupled to ICARUS standard cooling shield with boiling N 2 Insulation top Top flanges (final layout) GTT technique developed for 50 years/ and widely used for large industrial storage vessels and ships for liquefied natural gas. Expected heat loss through the insulation: T kw ; T kw

12 PAC_FNAL 23 January 2014 Magnetizing LAr Slide: 23 The addition of magnetic field to the LAr-TPC detector has been already described in the first ICARUS proposals (1985). An appropriate magnetic field to the LAr-TPC permits to further contribute to the progress of LAr technology, allowing the unambiguous determination of the sign and momentum of the secondary charged particles and a greatly improved visibility of the e.m. showers. Example of a 4 GeV e-neutrino event in LAr-TPC with 1 Tesla magnetic field. A negative electron, p 0, p + and proton are recognized in the final state

13 PAC_FNAL 23 January 2014 Possible solutions Slide: 24 Although hot superconductors may also be possible, a more conventional approach seems to be also suitable, based on recently developed technologies. The standard Niobium-Titanium superconducting cable would depend on a rather sophisticated cryogenic system that uses liquid Helium at 4.2 K K. We consider new SC wires based on Magnesium Diboride (MgB 2 ) that offers the major advantage to remain functional at up to 25 K. This superconductor, developed at CERN with IASS in collaboration with industry can be cooled using Helium gas (as opposed to liquid Helium), simplifying the demands on the cryogenic system. In addition, MgB 2 can work with a temperature margin of several degrees, a great advantage from the operation point of view.

14 T150 Configuration with magnetization B-field equiintensity lines (Tesla) The SC cable at 20 K is inserted inside the LAr environment at 80 K with help of vacuum and mylar super-insulation PAC_FNAL 23 January 2014 Similar layout is foreseen for the T600 detector Slide: 25

15 PAC_FNAL 23 January 2014 Recombination effects Slide: 26 None of the electron recombination theories developed so far is fully successful in describing all the experimental data in liquid argon. Nevertheless, they provide the basis for its understanding and for all phenomenological approaches. The recombination effect has been already carefully studied by us and it is a very important process which needs to be further studied. There are several minor additives to the LAr which modify this effect, transforming some of the produced light into additional ionization which could be useful also for the future LBNE programme.

16 PAC_FNAL 23 January 2014 Slide: 27 Doping with tetra-methyl-germanium (TMG) The nonlinear detector response may degrade the particle identification capability of the LAr-TPC. A possible solution to improve the linearity of the detector response is to introduce photo-sensitive dopants able to convert part of the scintillation light into additional free electron-ion pairs, thus enhancing the linearity as a function of the deposited energy density and electric field. We have chosen TMG as photo-sensitive dopant since: TMG is not absorbed in the recirculation system; pure TMG can be easily purified to an electron lifetime better than 10 µs; TMG has a large photo-absorption cross section of 62 Mbarn and has an acceptable quantum efficiency. The performance of the detector is greatly improved and is remarkably stable in time. A signal of +25% to +220% was found from 1.6 to 32 MeV/cm.

17 PAC_FNAL 23 January 2014 Slide: 28 Doping with tetra-methyl-germanium (TMG) Collected charge and deposited energy at an electric field of 200 V/cm and TMG concentration of 1.3 ppm and 3.5 ppm from stopping muon and proton events. Time evolution at 300 V/cm during the LAr doping with TMG. 3 ton LArTPC 10 ms lifetime

18 Modifications on the ICARUS Electronics The T600 system is being re-designed adopting a modern switched I/O and the parallelization of data flows, with an upgrading programme to realize: A more compact electronics both for analogue and digital; Improvements of the signal to noise ratio shortening cables; Integrating electronics onto the flanges with lower power; Adopting serial switched I/O for data flow. This layout is also suitable for housing front-end amplifiers in LAr in order to improve S/N. PAC_FNAL 23 January 2014 I/O connectors (Optical, Lemo, Ethernet) Power distribution on auxiliary connectors on side bus Backplane integrated on flange Slide: 29

19 Logistics PAC_FNAL 23 January 2014 Slide: 43 The T600 and the T150 will arrive at FNAL largely preassembled. The main assembly operations to be done at FNAL will be: re-assembly of the thermal insulation from 8 10 large sections; re-assembly of the cold shield from large (8-10) and pretested sections; insertion of the TPC containers in the insulation plus cold shield; assembly of the cryogenic plant from ready to go and pretested components (transfer lines, auxiliary reservoirs, pumps, controls, etc.); electronics cabinets installation and external cabling.

20 Conclusions In the next 2 years ICARUS will be considerably improved at CERN with an extensive R&D program, in a close collaboration with LBNE experiment of which several INFN groups are now members. In analogy with traditional bubble chambers a SC magnetic field of ~1 T will be applied to the LAr-TPC s. During 2016 it is proposed to move the whole experiment to FNAL short base line neutrino beams. The presence of ICARUS at FNAL is an important addition to MicroBooNE since, in the absence of anomalies, the n spectra in several detectors at different distances should be a precise copy of each other. A definitive clarification of the LSND anti-neutrino anomaly requires also the exploration of the anti-n signal, with the necessary inclusion of a magnetic field and the adequate mass of the T600. The T600 may also record on the same time a large number of νe events from the off-axis NUMI beam to adequately prepare for the LBNE long baseline. The ICARUS program may be operated as an additional element of the short baseline neutrino FNAL physics program. Intended primarily in the framework of the preparatory work for the LBNE collaboration, the ICARUS team is interested in extending the participation to other short baseline neutrino activities collaborating with the already existing FNAL groups. Bertolucci_26Nov 2013 Slide# : 44

21 Thank you! LNGS_May2011 Slide 45 PAC_FNAL 23 January 2014