International collaboration NEXT- Neutrino Experiment with a Xenon TPC General goals:  Search for neutrinoless double-beta decay.  Determination of the nature of the neutrino. Coimbra, May 15, 20141

NEXT – Portuguese team LIBPhys-UC ( LIBPhys-UC (Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics)  3 senior, 2 postdoc, 2 PhD, 1 Master, 1 technician LIP-Coimbra LIP-Coimbra  4 senior, 1 Master I3N, University of Aveiro  1 senior, 1 postdoc, 1 PhD student Coimbra, May 15, 20142

LIBPhys Team Coimbra, May 15, 20143

LIBPhys Activities Coimbra, May 15, Absolute measurement of the Xe electroluminescence yield, for pressures up to 10 bar, using different VUV photosensor readouts. Electroluminescence studies in Xe-CH4 and Xe-CO2 mixtures, using PMTs as VUV photosensors, for different pressures. Collaboration in the study of alternative Xe VUV photosensors for NEXT, including APDs, Micromegas and SiPMs. Study of different types of SiPMs for VUV scintillation readout. Activities coordinated between L.M.P. Fernandes and N. Yahlali. Participation in the scientific run at LSC, Canfranc, Spain.

LIBPhys Funding Coimbra, May 15, FCT/COMPETE project: PTDC/FIS/103860/2008 ( €) Apr’2010 – Sep’2012 Electroluminescence studies in Coimbra. Participation in collaboration meetings and missions to Spain. Equipment/human resources needed in Coimbra.

LIP-Coimbra Team Coimbra, May 15, 20146

LIP-Coimbra Funding/Activities Coimbra, May 15, FCT/COMPETE project: PTDC/FIS/112272/2009 (105 k€) High Pressure Xenon Doped Mixtures for the NEXT Collaboration  Development of an experimental system to study properties of Xe based mixtures with molecular additives.  Experimental study of molecular mixtures of potencial interest for the NEXT experiment.  Development of a Monte Carlo simulation model for gas mixtures of interest to complement the experimental study.

I3N-Aveiro Team Coimbra, May 15,  Publications: 2 peer review papers  PhD Theses: 1 finished, 1 underway

I3N-Aveiro Activities Coimbra, May 15,  Characterization and response of several types of SiPMs.  Simulation of the electroluminescence and statistical fluctuations associated for pure xenon.  Simulation of drift velocities and diffusion in pure xenon and mixtures (up to 2%) with CO2, CH4, Ethane, DME, Isobuthane, N2, H2, CF4 and TMA for different drift fields. Underway and in the near future:  Simulation of S1 and S2, W and Ws, for the different mixtures.  Participation in the commissioning of NEXT-NEW in Canfranc.

1. SiPMs coated with TPB: coating protocol and characterization for NEXT, V. Álvarez et al., JINST 7 (2012) P NEXT-100 Technical Design Report (TDR). Executive summary, V. Álvarez et al., JINST 7 (2012) T Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements, V. Álvarez et al., JINST 8 (2013) T Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment, V. Álvarez et al., JINST 8 (2013) P Near-Intrinsic Energy Resolution for 30 to 662 keV Gamma Rays in a High Pressure Xenon Electroluminescent TPC, V. Álvarez et al., Nucl. Instrum. Meth. A 708 (2013) Ionization and scintillation response of high-pressure xenon gas to alpha particles, V. Álvarez et al., JINST 8 (2013) P Publications (general) Coimbra, May 15,

7. Design and characterization of the SiPM tracking system of NEXT-DEMO, a demonstrator prototype of the NEXT-100 experiment, V. Álvarez et al., JINST 8 (2013) T Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array, V. Álvarez et al., JINST 8 (2013) P Present Status and Future Perspectives of the NEXT Experiment, J.J. Gómez Cadenas et al., Adv. High Energy Phys (2014) Description and commissioning of NEXT-MM prototype: first results from operation in a Xenon-Trimethylamine gas mixture, V. Álvarez et al., JINST 9 (2014) P Characterisation of NEXT-DEMO using xenon Ka X-rays, D. Lorca et al., JINST 9 (2014) P PMT calibration of a scintillation detector using primary scintillation, E.D.C. Freitas et al., JINST 10 (2015) C Publications (general) Coimbra, May 15,

 Secondary scintillation yield in high-pressure xenon gas for neutrinoless double beta decay (0νββ) search, E.D.C. Freitas et al., Phys. Lett. B 684 (2010) 205.  Primary and secondary scintillation measurements in a Xenon Gas Proportional Scintillation Counter, L.M.P. Fernandes et al., JINST 5 (2010) P  Micromegas operation in high pressure xenon: charge and scintillation readout, C. Balan et al., JINST 6 (2011) P  Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search, C.M.B. Monteiro et al., Phys. Lett. B 714 (2012) 18.  Characterization of the Hamamatsu S8664 avalanche photodiode for X- ray and VUV-light detection, T. Lux et al., Nucl. Instrum. Meth. A 685 (2012) 11.  “Imaging with SiPMs in noble-gas detectors”, N. Yahlali, L.M.P. Fernandes, K. González, A.N.C. Garcia and A. Soriano, JINST 8 (2013) C Publications LIBPhys-UC Coimbra, May 15,

 Drift field limitations to the energy resolution in Time Projection Chambers for 136Xe neutrino-less double beta decay search, P.N.B. Neves et al., Nucl. Instrum. Meth. A 641 (2011) 87.  A Monte Carlo study of the fluctuations in Xe electroluminescence yield: pure Xe vs Xe doped with CH4 or CF4 and planar vs cylindrical geometries, J. Escada et al., JINST 6 (2011) P  New Contribution to the Experimental Measurement of the N4+ Ion Mobility in N2 at 298K, A.N.C. Garcia et al., JINST 7 (2011) P  Experimental ion mobility measurements in Xe-N2 mixtures, A.N.C. Garcia et al., JINST 9 (2014) P Publications LIP-Coimbra Coimbra, May 15,

LIBPhys-UC: MSc Thesis: Studies of MicroMegas performances in pure Xenon and at high pressure for NEXT Experiment, Catalin Balan, Univ. Coimbra(2010 ). PhD Thesis: Studies on high pressure xenon scintillation and photosensor alternatives for the NEXT experiment, Elisabete Freitas, Univ. Coimbra (2013). MSc Thesis: Determination of the electroluminescence yield in mixtures of xenon with small quantities of CH4, Marina Jorge, Univ. Coimbra (2014). LIP-Coimbra: MSc Thesis: Gaseous Mixtures/Detection Media Studies for NEXT Experiment: a Contribution, Alexandre Garcia, Univ. Coimbra (2012). PhD/MSc theses published Coimbra, May 15,

LIBPhys-UC: MSc project: Experimental Measurement of the Electroluminescence Yield, Electron Drift Velocity and Intrinsic Energy Resolution for Mixtures of Xenon with sub-percentage quantities of CO2 for the NEXT Experiment, Daniel Mano, LIBPhys, Univ. Coimbra. PhD project: R&D on the feasibility of Ba tagging in High Pressure Xenon Chambers, Carlos Henriques, LIBPhys, Univ. Coimbra. I3N-Aveiro: PhD project: Luis Moutinho, I3N, Univ. Aveiro. PhD/MSc projects underway Coimbra, May 15,

LIBPhys-UC:  Xenon scintillation induced by X-rays, L.M.P. Fernandes, 2010 European Conference on X-ray Spectrometry, Figueira da Foz, Portugal.  Experimental Determination of the Electroluminescence Yield in GEMs and THGEMs Operating in Gaseous Argon and Xenon, L.M.P. Fernandes, 2011 IEEE Nuclear Science Symposium, Valencia, Spain. LIP-Coimbra:  Electroluminescence in noble gases: simulation and experimental results, F.P. Santos, Invited presentation at ANT 2013, Sunnyside, Tahoe City, USA, May Presentations Coimbra, May 15,

LIBPhys-UC:  Continuation of studies with xenon additives to increase the drift velocity and decrease diffusion, not compromising the electroluminescence yield, using the NEXT-DEMO chamber.  Comissioning of the NEXT-NEW TPC in Canfranc  Test of new SiPMs from SensL for VUV light. LIP-Coimbra:  Xe-TMA, Xe-CF4 and Xe-CH4 mixtures investigated (both experimentally and by simulation), but discarded as possible additives in NEXT. TEA is the next candidate to investigate. Prospects for the near future Coimbra, May 15,