WP2 Background simulations Outline Execution plan for the third year Progress of the work Activities and news

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 JRA1-WP2 N3-BSNS JRA2(IDEA)WP3-B1 Development of a standard library of background simulation codes BackgroundSimulation,Neutron-Shield and Muon-Vetos and Muon-Vetos Study on Cosmogenic Induced Activity Induced Activity

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 General issues

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 Plan for the third year Analysis of data collected in the background monitoring campaign with MC codes Optimisation of the codes Tasks Design and implementation of the library –Standard codes for specific task –End-to-end simulation tools for experiments. Milestones and deliverables

Analysis of collected data and optimisation of codes

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 Muon simulations and MUSUN Muon backgrounds at Super-Kamiokande, KamLAND and CHOOZ are calculated using MUSIC (hep-ph/ ) Phys.Rev. D74 (2006) –Use of digital maps and mountain profiles –Real composition of the rock (approximate in CHOOZ) –Modified Gaisser atmospheric muon parametrization in the large angle and small energy regimes –Well tested Monte Carlo integration method

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 Muon simulation and LSC measurements GOAL To help in the understanding and interpretation of muon measurements in Zaragoza and Canfranc FEATURES Code: FLUKA simulation Geometry: real mountain profile Primary particles: muons with energy spectrum and angular distribution corresponding to 2800 m above sea level. Output: muons traversing laboratory walls, flux and energy distribution.

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 Muon induced Background Monte Carlo evaluation of the muon induced background in the GERDA double-Beta decay experiment, Nuclear Instruments and Methods in Physics Research A 570 (2007) 149–158 –Background simulations with MaGe (Common Majorana G4 MC framework) –Study of the muon and neutron induced events –Study of the unstable isotopes produced by muons

Design of specific codes

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 ZEPLIN-III Software It models the instrument response to radioactive backgrounds and calibration sources Astroparticle Phys. 26 (2006) 140 –Generation –Ray tracing and detection –Processing by data acquisition electronics The package builds upon previous G4 advanced example “Underground Physics” by A. Howard and H. Araújo.

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 MaGe: a Monte Carlo framework for the Gerda and Majorana double beta decay experiments Background reduction in neutrinoless double beta decay experiments using segmented detectors—A Monte Carlo study for the GERDA setup. NIMA 570 (2007) 479. –A Monte Carlo study of an array of 21 germanium crystals arranged according to the GERDA design was performed. The background rejection based on anticoincidence requirements for segmented and unsegmented germanium detectors was compared. Events with photons in the final state are significantly better identified, if segment anti-coincidences are used.

Activities and news

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 Presentations Aussois (FRANCE) - LRT06 - October 2006 – Neutron backgrounds, V. Kudryavtsev (Sheffield). Neutron backgrounds, – Muon induced signals and Isotope production in GERDA, L.Pandola (Gran Sasso). Muon induced signals and Isotope production in GERDA, Rhodes (GREECE) - IDM 06 - September 2006 – Neutron background in large-scale WIMP dark matter experiments, V. Kudryavtsev (Sheffield). Neutron background in large-scale WIMP dark matter experiments, – New measurement of the neutron flux at the Modane Underground Laboratory, R. Lemrani (Saclay). New measurement of the neutron flux at the Modane Underground Laboratory, – Background studies for a ton-scale argon dark matter detector, L. Kaufmann (Zurich). Background studies for a ton-scale argon dark matter detector,

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 Presentations II Rhodes (GREECE) - IDM 06 - September 2006 – Background characterization of the new Canfranc Underground Laboratory, G. Luzon (Zaragoza). Background characterization of the new Canfranc Underground Laboratory, – Measurement of the neutron background from rock at Boulby mine, E. Tziaferi (Sheffield). Measurement of the neutron background from rock at Boulby mine, – Shielding design simulations for future large-scale dark matter search experiments, M. Bauer (Tuebingen). Shielding design simulations for future large-scale dark matter search experiments, – Simulation of inelastic neutron scattering with GEANT4, S. Scholl (Tuebingen). Simulation of inelastic neutron scattering with GEANT4, – Calculation of neutron yield from radioactivity in materials relevant to dark matter searches, V. Tomasello (Sheffield). Calculation of neutron yield from radioactivity in materials relevant to dark matter searches, – Background studies for the pn-CCD detector of CAST, A. R. Arruga (Zaragoza). poster Background studies for the pn-CCD detector of CAST,

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 Publications A. Tang et al, Muon Simulations for Super-Kamiokande, KamLAND and CHOOZ, Phys.Rev. D74 (2006) H. Araújo et al., The ZEPLIN-III dark matter detector: performance study using an end-to-end simulation tool, Astroparticle Phys. 26 (2006) 140 R. Lemrani et al., Low-energy neutron propagation in MCNPX and GEANT4, NIM A (2006) 454 L. Pandola et al., Monte Carlo evaluation of the muon induced background in the GERDA double-Beta decay experiment, NIM A 570 (2007) 149–158 I. Abt et al, Background reduction in neutrinoless double beta decay experiments using segmented detectors—A Monte Carlo study for the GERDA setup. NIMA 570 (2007) 479.

G. Luzón, JRA1 Meeting, Zaragoza,10-11 July 2006 WP1-CANFRANC Low background measurements bench ready about April 07 –Two new 2kg HPGe detectors –In phase of characterization and shielding building –Two existing 1kg HPGe detectors –Taking data –One LB NaI detector 3x3” –Characterization Gamma+Radon measurements in Sept 07 (TARI) A neutron detector is to be acquired.