Cosmogenic induced activity Susana Cebrián Universidad de Zaragoza / Università di Milano-Bicocca IDEA (Integrated Double-beta decay European Activities) Heidelberg, 21 st -22 nd October 2004 Task leaders: Maura Pavan, Susana Cebrián

 Participants: Heidelberg: G. Heusser, B. Schwingenheuer Milano: S. Capelli, O. Cremonesi, M. Pavan Zaragoza: B. Beltrán, J. M. Carmona, S. Cebrián, H. Gómez, G. Luzón, I. G. Irastorza, J. Morales, A. Rodríguez, J. Ruz, L. Torres South Carolina (non-EU, on a self-financing basis) S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Presentation  “ Cosmogenic induced activity” is the Work Package 4 of JRA2 / IDEA in ILIAS, in connection with: Task 2 (Development of a standard library of background simulation codes) Task 4 (R&D on radiopurity of materials and purification techniques) of JRA1 (Low background techniques for deep underground science) Attendance to JRA1 meeting held in Edinburgh on 10 th September 2004

S. Cebrián, Cosmogenic Induced Activity  Detailed implementation plan for first 18 months IDEA meeting, Heidelberg, October 2004 Outline of the talk Task 1: presentation of found results Task 2: description of codes and comparison Task 3: description and results of the activation study for TeO 2 Future work and summary

Search for p/n activation cross-sections on targets of interest (Ge, Te) on the literature and from nuclear data libraries Task 1: Collection of available data on cross- sections DELIVERABLE: Summary of non-existing measurements of cross-sections of interest and existing reliable measurements which can be used to test the codes Available at IDEA website: Outline of this part General description and found results for: - EXFOR- RNAL - MENDL- Library up to 1.7 GeV - Individual refences

EXFOR (CSISRS in USA) compilation of experimental nuclear reaction data easy searches into the SQL database, via web full access to data and references S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 information in EXFOR is not enough to make a complete activation study but essential to check calculated results some  for (n,X) and (p,X) processes on Te and Ge targets p+Ge: some results for worrisome products like 60 Co and 68 Ge/ 68 Ga mainly from an irradiation experiment at 660 MeV Yu.V.Aleksandrov et al, Bulletin of the Russian Academy of Sciences - Physics, 59 (1995) 895. p+Te: some results for I, Sb, and Te products but not for 60 Co mainly from an irradiation experiment at 1.7 GeV E. Porras et al, NIM B 160 (2000) 73 more data for Cu and Pb

RNAL (Reference Neutron Activation Library) library of evaluated cross sections for neutron-induced reactions leading to radioactive products format ENDF6 restricted to 255 reactions: no result for Ge,  for some (n,  ) processes on Te isotopes and for different reactions on Se, Xe, Mo, Cd, Cu or Pb MENDL-2 (Medium Energy Nuclear Data Library) and MENDL-2P ftp://iaeand.iaea.or.at/ “Neutron reaction data library for nuclear activation and transmutation at intermediate energies”, “Proton reaction data library for nuclear activation”, by Yu.N. Shubin et al. S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 not very useful for DBD activation studies, altough some results can be considered for checking detailed excitation functions calculated using the ALICE family of codes, checked against experimental data very wide range of targets and products, but no information on 60 Co for Te isotopes independent results for n and p as projectiles only up to 100 MeV for neutrons and 200 MeV for protons used in GEANT4 for calculating isotope production

S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 comparison of MENDL-2P and EXFOR results for production of some I isotopes on nat Te (equivalent cross-checks can be made for production of Zn, Ga, Ge and As isotopes on Ge) MENDL is a valuable tool for activation studies, but with a very limited energy range for cosmogenics

Production  libraries for n and p to 1.7 GeV “Production and Validation of Isotope Production Cross-Section Libraries for Neutrons and Protons to 1.7 GeV”, S. G. Mashnik et al, [arXiv:nucl-th/ ]. “Study of Isotope Production in High Power Accelerators: Detailed Report”, K. A. Van Riper et al, LA-UR evaluated library of excitation functions including available experimental data and calculated results using the most suitable codes independent results for n and p as projectiles up to 1.7 GeV covering ~1/3 of natural elements products of medical interest S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 targets products This library can be very useful specially for studying activation in Ge DBD experiments

S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

Results from individual references on Ge Calculated neutron-induced excitation functions on natural Ge isotopes for 68 Ge, 65 Zn, 58 Co, A-2 Ga and A-3 Ga F. T. Avignone et al., Nucl. Instr. B (Proc. Suppl.) 28A (1992) and for 68 Ge using LAHET Majorana Collaboration, [arXiv.org:nucl-ex/ ] Measured production of 60 Co in Ge by p at 800 MeV E. Norman, Poster at Neutrino 2004, Paris. To appear in NPB (PS). S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Results from individual references on Te and Mo Irradiation experiments at Berkeley with protons at 0.8, 1.85 and 5 GeV, obtaining many production , with recent evaluation of 60 Co results D. W. Bardayan et al, Phys. Rev. C 55 (1997) 820. E. Norman, Poster at Neutrino 2004, Paris. To appear in NPB (PS). EXFOR, 660 MeV 800 MeV

Some experimental results are available for relevant production  at fixed energies on Te and Ge from individual references and the EXFOR database, coming from proton irradiation experiments o Not sufficient for a complete activation study but extremely useful to check complementary calculations S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Conclusions for Task 1 The MENDL libraries offer reliable excitation functions for many targets and products up to 100 MeV for n and 200 MeV for p Some evaluated excitation functions have been derived for some products on Ge isotopes

Collect information on: Target materials and product isotopes covered Projectiles allowed Range of applicable energies Physical models included and/or experimental data sets considered for cross-sections Checks with experimental data “Technical” information: language, code source, support,... Task 2: Analysis of computational codes for n/p activation DELIVERABLE: Report summarizing the features and limitations of the existing codes, deciding on the most suitable ones to be used/improved in the study of activation in DBD experiments Coming soon … Outline of this part - Semiempirical codes - Hadronic Monte Carlo codes - General-purpose Monte Carlo codes

S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Semiempirical codes Based on Silberberg&Tsao equations for cross-sections of different processes producing residual nuclei (spallation, fission, …) Ap. J. Suppl. 25 (1973) 315, Ap. J. Suppl. 25 (1973) 335, Ap. J. Suppl. 35 (1977) 129, Ap. J. Suppl. 58 (1985) 873, Phys. Rep. 191 (1990) 351, Ap. J. 501 (1998) 911.  COSMOmodified versions with new releases of formulas different outputs: production , mass yield curves, activity C. J. Martoff, P. D. Lewin, Comput. Phys. Commun. 72 (1992) 96.   for Ge and Cu J. Bockholt, PhD thesis, University of Heidelberg,  YIELDXprovided by Tsao with the updated formulas output: production 

Hadronic Monte Carlo codes  Many families of codes based on the Monte Carlo simulation of the hadronic interactions between nucleons and nuclei: HETC, CEM, LAHET, ISABEL, INUCL, CASCADE, ALICE, SHIELD, MARS, GEM, LAQGSM, … S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Versions of many of them available at the Nuclear Energy Agency (NEA) Data Bank: Someones compared and checked against experimental data in a global NEA study (on O, Al, Fe, Co, Zr, and Au targets) : “International Codes and Model Intercomparison for Intermediate Energy Activation Yields”, NSC/DOC(97)-1, January and extensively compared with particular measurements of production  irradiating targets with protons M. Gloris et al, NIMB 113 (1996) 429 R. Michel et al, NIMB 129 (1997) 153 Gilabert et al, NIMB 145 (1998) 293 Yu. E. Titarenko et al, [arXiv:nucl-ex/ ] S. G. Mashnik et al, [arXiv:nucl-th/ ] Yu. E. Titarenko et al, [arXiv:nucl-ex/ ] … and many more!

S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 codehistoryphysicsenergy range LAHET Developed at Los Alamos based on HETC (Oak Ridge) adding ISABEL/VEGAS Version 2.8 available at NEA requiring MCNP Version 3 released in 2001 including INUCL and ABLA Included in MCNPX 2.4 cascade +[preequilibtium] +evaporation +fission up to 3.5 GeV for nucleons CEM Started at Dubna CEM95 available at NEA and included in MCNPX 2.4 CEM2k included in MCNPX 2.5 CEM2k merged with GEM2 (fission) cascade +preequilibrium +evaporation 10 MeV-5 GeV ALICE ALICE91 available at NEA Many different versions: AREL, HMS-ALICE, ALICE-IPPE… Used for the MENDL libraries precompound decay up to ~200 MeV  Features of some codes (used to create a library, as considered the most reliable ones) the relative role of each process giving rise to nuclei production changes with targets, products and projectile energies so for different activation problems the most suitable codes may be different

S. Cebrián, Cosmogenic Induced Activity NEA study in 1997: calculations of activation yields may at best have uncertainties of the order of a factor of two. Frequently, average deviations are much larger (may go up to two or three orders of magnitude). IDEA meeting, Heidelberg, October 2004  Conclusions from intercomparison of codes (even if not dealing with activation reactions of interest in DBD experiments) Measurements during 90s: predictive power of many codes is good (~2) in the near spallation region (products not far from the target) but worse in the deep spallation region or and much worse in the fission region Recent efforts to improve description of fission and fragmentation: o Merging some codes with fission models (CEM2k+GEM2, LAQGSM+GEM2) agreements up to % have been reported

General-purpose Monte Carlo codes codewebsiteHow to save nuclei production Physical models and data GEANT4 (C++) /geant4/ (G4IsoParticleChange) G4HadronicProcess:: GetIsotopeProduction Info() Different models available, based on parameterizations (GEISHA), evaluated data (MENDL) and theory (including other codes: HETC, INUCL, MARS) FLUKA ( FORTRAN77) estimator Neutron cross sections and/or information on production of residual nuclei available for Te / Ge in present version MCNPX (FORTRAN90) RES tally (version 2.5) Includes LAHET 2.8 and CEM95 (version 2.4) and CEM2k, INCL4 and ABLA (version 2.5) S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 the user can choose between different models and implementations to describe the hadronic physics

Monte Carlo codes + neutron activation studies possible - very time-consuming (specially for some products) General-purpose MC codes + wide coverage of projectiles, targets and energies in principle + easy availability and support + different models can be used for the hadronic physics - not many comparisons with measurements of activation yields available S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Which codes should we use in our DBD activation studies? Semiempirical routine YIELDX MC codes like GEANT4 / MCNPX trying different hadronic models Semiempirical codes + wide coverage of targets and products + short calculation time and simplicity of use - only proton-induced reactions Conclusions for Task 2

Study using different codes and comparing with data when possible Task 3: Comparison of results for some problems of interest DELIVERABLE: Report comparing the performances of different codes for particular problems of interest in DBD Identification of the most reliable codes Quantification of the uncertainties or spread in the estimates Identification of weak points of the codes when treating our problems Preliminary results for open questions in activation for DBD Outline of this part - GEANT4 simulations - comparisons with measured  - comparisons of excitation functions - activity yields Problem of activation in TeO 2 Relevant production  on Te and the corresponding activation yields have been estimated using YIELDX and GEANT4 and have been compared with all previous results

GEANT4 version p01 Projectiles: neutrons and protons Energy: discrete values from 10 MeV to 5 GeV Geometry: various samples of irradiation experiments implemented o nat Te disk (diameter 3.1 cm, height 0.67 cm) from Berkeley measurements at 1.85 GeV o CdTe box (5 x 5 x 2 mm 3 ) from measurement at 1.7 GeV Hadronic physics: different models taken into consideration o user-defined physics list: low and high energy parameterized models (LHEP) + evaluated cross-section data for neutrons up to 20 MeV o QGSP: theory driven model based on Quark Gluon String models o LHEP-BIC: LHEP + Binary cascade code below 3 GeV o LHEP-BERT: LHEP + Bertini cascade code below 3 GeV o LHEP-PRECO: LHEP + preequilibrium decay model below 100 MeV J. P. Wellisch, nucl-th/ , nucl-th/ , nucl-th/  GEANT4 simulations S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

Results from p irradiation on natural Te at 1.85 GeV in Berkeley vs GEANT4 simulation with different models  Comparison data- calculations for  modeldeviation factor F user physics list33.5 QGSP17.4 LHEP-BIC18.9 LHEP-BERT2.3 model chosen S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

Results for production cross-sections on Te from p irradiation at 1.85 GeV and at 1.7 GeV versus YIELDX semiempirical estimates and GEANT4 simulations order of the best accuracy expected in this kind of calculations in mb deviation factor F measurement- measurement 3.3 GEANT4- GEANT4 1.6 measurement- GEANT4 1.9 measurement- GEANT4 1.9 S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October GeV1.7 GeV exp YIELDX GEANT4

 Production cross-section for 60 Co absorption of  emissions = continuum in 2  | 0 region significant discrepancy COSMO – YIELDX in 1-3 GeV YIELDX S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

relevant difference for n/p activation at low energies acceptable agreement GEANT4 – MENDL/ YIELDX Contribution to background levels of muon-induced neutrons  Production cross-section for 124 Sb Cosmogenically induced activity in TeO 2 crystals help to decide if muon-vetos can be necessary in CUORE help to plan the construction and transport of crystals  emitter with Q= keV MENDL-2 below and YIELDX above 100 MeV agreement COSMO – YIELDX S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

 Production cross-section for 125 Sb  emitter with Q=766.7 keV (only in DM region) MENDL-2 below and YIELDX above 100 MeV S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

 Cosmic neutron spectrum  (E): E>20 MeV: n/cm 2 /s n/cm 2 /s From modified COSMO: D. Lal and B. Peters, Springer, T. W. Armstrong et al, J. Geophys. Res. 78 (1973) O.C. Allkofer and P.K.F. Grieder, Physics Data, 25-1, Parameterization based on measurements: J. F. Ziegler, IBM Journal of Research and Development 42 (1998) 1. S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

for t exp =4 months, t dec =2 years nuclideT 1/2 modified COSMO (CUORE Proposal)  : MENDL/YIELDX  : mod. COSMO  : MENDL/YIELDX  : Ziegler 60 Co5.27 y Sb60.2 d Sb2.76 y  Results for activity in TeO 2 : Activity of 60 Co is almost one order of magnitude smaller using YIELDX cross-sections, regardless of the neutron spectrum used Sb activity could be higher (factor 2) considering other neutron spectrum in  Bq / kg Contributions below + above 100 MeV S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004

GEANT4 has been used to estimate some production  in Te, compared with available measurements o At high energies, LHEP_BERT physics list gives the best agreement, being the deviation factor ~2 o Deviations between YIELDX (Silberberg&Tsao) and GEANT4 are also ~2 S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Conclusions for Task 3 From the activation study in TeO 2 Excitation functions have been described combining MENDL and YIELDX results below and above 100 MeV Activity yields for TeO 2 crystals have been derived and compared with previous estimates based on a modified COSMO

S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Task 2: complete analysis of codes Task 3: continue the study of particular problems activation in TeO 2 activation in Ge Task 4: start the design of new irradiation experiments Future work

S. Cebrián, Cosmogenic Induced ActivityIDEA meeting, Heidelberg, October 2004 Summary A report has been prepared describing the available sources of data for isotope production cross sections of interest in DBD experiments Semiempirical and Monte Carlo codes for activation studies are being analyzed and compared to find the most suitable ones An study of the cosmogenic activation for TeO 2 is underway using different codes and available data