Current Status of the Construction of the Angra Antineutrino Detector

Transcription

1 Current Status of the Construction of the Angra Antineutrino Detector

2 ANGRA Collaboration: Brazilian Institutions: CBPF J.C. Anjos, G.L. Azzi, A.F. Barbosa, R.M.O. Galvão, H. Lima Jr, M. Vaz Graduate Students: Marcelo Nascimento Souza (PhD) Thamys Abrahão (MSc) Marcio Nunes (MSc) Andre G. Oliveira (MSc) Rafael Gama (MSc) Wallace R. Ferreira (MSc) Aridio Schiapazza (MSc) Vitor Ferraz (MSc) Undergraduate Students: Upiratan Beatriz 15/09/11 J.C.Anjos-AAP

3 The ANGRA Collaboration: UNICAMP E. Kemp, T. Bezerra, L. F. González, T. Junqueira UFABC Marcelo Leigui, R. Da Maceno, P. Chimenti UFJF Luciano M. Andrade, Rafael A. Nóbrega, Augusto S. Cerqueira UFBA Iuri M. Pepe Paulo Farias UEFS Germano P. Guedes PUC-RJ Hiroshi Nunokawa 15/09/11 J.C.Anjos-AAP

4 The ANGRA Collaboration: International group A. Bernstein, N. Bowden D. Reyna L. Villaseñor, E. Casimiro Linares Walter Fulgione, M.Aglietta 15/09/11 J.C.Anjos-AAP

5 Neutrinos Angra Project Development of new techniques for nuclear reactor monitoring 15/09/11 J.C.Anjos-AAP

6 15/09/11 J.C.Anjos-AAP

7 15/09/11 J.C.Anjos-AAP

8 DETECTOR STATUS 15/09/11 J.C.Anjos-AAP

9 Existing Infrastructure at ANGRA - Old 20 HC container placed next to reactor containment - Currently measuring background muon flux - Remote data acquisition from Angra-CBPF 15/09/11 J.C.Anjos-AAP

10 New container being prepared: size 40 High Cube model, for better shielding Top view of the container showing detector position 15/09/11 J.C.Anjos-AAP

11 external water shield Central detector: Gd loaded water with 40 PMTs to detector Cherenkov radiation 15/09/11 J.C.Anjos-AAP

12 Detector design (2011) Optimisation of number of PMTs: (detector + muon veto) Simulation with GEANT4 (2 MeV positrons at the center of the detector) Central detector: Gd loaded water with 40 PMTs to detector Cherenkov radiation 15/09/11 J.C.Anjos-AAP

13 Modeling of PMT fixture 15/09/11 J.C.Anjos-AAP

14 Prototype of the central detector Mechanical Project of Sarcophage ] External box: iron Internal box: Polypropilene PMT test setup 15/09/11 J.C.Anjos-AAP

15 Setup for testing efficiency of PMT photo-cathode Mounting of PMTs in the prototype tank 15/09/11 J.C.Anjos-AAP

16 Setup for testing efficiency of PMT photo-cathode Mounting of the prototype tank 15/09/11 J.C.Anjos-AAP

17 Setup for testing efficiency of PMT photo-cathode Mechanical project PMT Hat Mounting of the PMT hat 15/09/11 J.C.Anjos-AAP

18 Single Photoelectron Charge Spectrum Nu-DAQ 15/09/11 J.C.Anjos-AAP

19 Construction of a 50 l prototype for neutron detection in Gd loaded water ( 1 PMT) 252 Californium source donated by CDTN / MG (2010); Instalation of a small laboratory in the old CBPF linear accelerator tunnel; Authorization to use the neutron source given by CNEN in 2011; Some work still needs to be done Instalation of water purification station concluded; 15/09/11 J.C.Anjos-AAP

20 Muon outer veto project 15/09/11 J.C.Anjos-AAP

21 Testing Setup to test the multi-anode PMT H7546B 15/09/11 J.C.Anjos-AAP

22 ELECTRONICS STATUS 15/09/11 J.C.Anjos-AAP

23 Muon electronics - conceptual diagram (2007) PMT trigger logic FPGAs control and status registers Front-end electronics signal conditioning ADC 125 MHz 10 bits leading-edge discriminator stop TDC 81 ps 28 bits time encoding data builder DC level-1 trigger start* FIFO * trigger pulse from previous event control addr VME bus data 15/09/11 J.C.Anjos-AAP

24 Herman Lima Jr VII Encontro Neutrinos Angra UFJF 1-3 de junho de 2011

25 Lay-out of VME board developed in collaboration with Brazilian industry CADSERVICE Ten units produced for tests Components mounted by CADSERVICE (Campinas, SP) 15/09/11 J.C.Anjos-AAP

26 Optimized Digital Detection for the Trigger System. Luciano M. de A. Filho (UFJF) Augusto Santiago (UFJF) A. F. Barbosa (CBPF) 26 15/09/11 J.C.Anjos-AAP

27 Proposal Digital Filter to maximize signal/background ra8on before the trigger. Implementa8on Filter FIR. Two methods tested 1. Joint Filter. 2. Op8mized Filter for amplitude es8mate. Similar results for both filters. Op8mized filter has advantage of output in Volts. Central FPGA of NDAQ ADC Digital Filter Trigger Decision Increase signal/ background ra8o 15/09/11 J.C.Anjos-AAP

28 Optimal filter for amplitude estimate Signal before the filter Signal aier the filter 15/09/11 J.C.Anjos-AAP

29 Results Peak/Valley = 2.5 Peak/Valley = 5.0 ANTES DEPOIS Variance of the measurement: Error in the measurement: 15/09/11 J.C.Anjos-AAP

30 Detector Simulation Studies 15/09/11 J.C.Anjos-AAP

31 Simulation Software for photon propagation in the Central Detector Rafael Antunes Nóbrega Universidade Federal de Juiz de Fora - UFJF Faculdade de Engenharia Elétrica 15/09/11 J.C.Anjos-AAP

32 Event Generation 15/09/11 J.C.Anjos-AAP

33 Detector Geometry Studies: With or without Winston cones? Configuration 1 UP Média / 100 Ev. 77 (+19%) Hits/100 Ev./PMT < > 85 FRONT BACK DOWN Gustavo Valdiviesso (UFAlfenas) 15/09/11 J.C.Anjos-AAP

34 Conclusion of the Detector Geometry Studies Geometric configuration of the 40 PMTs does not affect neutrino signal. Final configuration to optimize muon rejection. Better signal with Winston cones (16% more light), but technical difficulties to implement (construction, cost... ). Polyethilene Shielding generates at least the double of neutrons by spallation than water Internal surface should be reflective but does not need to be polished. 15/09/11 J.C.Anjos-AAP

35 Data Analysis: simulation of expected signal and background Signal and background Simulation: Positrons (from neutrino interaction) Neutrons (from neutrino interaction) Cosmic Muons Cosmic Neutrons 15/09/11 J.C.Anjos-AAP

36 GEANT4: antineutrino signal positron signal (prompt) Neutron capture in Gd signal Distribuition of total number of photo electrons (p.e.) observed 15/09/11 J.C.Anjos-AAP

37 GEANT4: muon background Cherenkov signal of a muon in the target 15/09/11 J.C.Anjos-AAP

38 10 MeV neutron GEANT4: study of neutron shielding Fluxo Experimental medido no LNGS (1000 m): En > 10 MeV N_flux = 75 n/m 2.s Angra (nível do mar): redução 3x N_flux = 25 n/m 2.s Atenuação da blindagem ( ~ 85% acima de 10 MeV) N_flux = 4 n/m 2.s ~ 5% de contaminação 15/09/11 J.C.Anjos-AAP

39 Counts The time interval for both neutron capture in Gd and consecutive cosmic rays arrival follow a Poisson distribution The probability for an event to occur after a time interval t is: One day neutrino detection time spectrum 1/λ = average time interval between events 1/λ ν 30µs = time average for n capture Average 30µs µs 1/λ μ 1ms = time average for cosmic muons 39 15/09/11 J.C.Anjos-AAP

40 Data acquisition simulation Simulated data for one day of data taking and data reduction by each selection criteria 15/09/11 J.C.Anjos-AAP

41 Data acquisition simulation Simulated data for one day of data taking and data reduction by each selection criteria 15/09/11 J.C.Anjos-AAP

42 Data acquisition simulation 15/09/11 J.C.Anjos-AAP

43 Data acquisition simulation Fit Result: Neutrino events estimated within ~ 8% uncertainty 15/09/11 J.C.Anjos-AAP

44 Conclusions Previous experiments demonstrated a good capability of using antineutrinos for nuclear reactor distant monitoring. Neutrino laboratory already installed in Angra Muon detection (background estimate) and remote data acquisition (CBPF-Angra link) working. Simulation is running and guiding final detector design. Electronics is ready for production phase Expected data taking by beginning 2012 Good opportunity to develop experimental neutrino physics in Brazil and to contribute to new safeguards techniques. Good opportunity to interact with local industry. 15/09/11 J.C.Anjos-AAP

45 Thank you!