Development of a standard library of background simulation codes JRA1 WP2 Development of a standard library of background simulation codes The second WP inside the joint research activity 1 of ILIAS about Low background Techniques for Deep underground Science is devoted to the Development of a standard library of background simulation codes in close connection to the other WP whose main objective is to measure environmental background, radioactivity of materials and to collect data. We could summarize the objectives in a few words: the creation of a coherent and well tested library of MC codes available for all the users of the underground labs.

Special Cross-links JRA1-WP2 JRA2(IDEA) WP3-B1 N3-BSNS Development of a standard library of background simulation codes JRA2(IDEA) WP3-B1 N3-BSNS Background Simulation, Neutron-Shield and Muon-Vetos Study on Cosmogenic Induced Activity Of course, this working group will be working together with the other WP of JRA1, but we should also share simulation works and activities with the WP (Background simulation and neutron shielding) of the network N3 on Dark Matter and with the WP-B1 (materials activation simulation) of JRA2( Integrated double beta decay) 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Planning for the first year Existing codes compared and discussed. Platform, language and structure of the library fixed. First set of MC codes for relevant background components and instrumentation ready. Tasks Milestones and deliverables First “test” version of MC libraries implemented. Technical report prepared. The first year we are collecting the most used codes. We must compare the codes ( with experimental data and also with other codes) and discuss these results. We have also to agree a platform, language and structure for the library of codes where to locate the first set of MC codes. The deliverables of this year will be a first version of MC libraries and a technical report. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Progress of the work Task A: Existing codes compared and discussed. Task B: Platform, language and structure of the library fixed. Task C: First set of MC codes for relevant background components and instrumentation ready. Now, I will talk about the progress of the work.

Task A: comparison of codes Comparison experimental results. Comparison of codes. Modifications to codes. For the comparison of codes I will just mention some results since in the next talk Vitaly will show you a complete review on the status of the art. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Comparison experimental results Published neutron flux measurements at Gran Sasso, Modane, Canfranc, CPL (Korea) and others. Measurements of muon-induced neutrons at various depths underground: neutron yields, energy spectra, lateral distributions etc.: LVD, KARMEN, LSD etc. Measurements of muon-induced neutrons using active vetoes for dark matter detectors (existing and planned): Canfranc, Modane, Boulby, Gran Sasso. Planned background flux measurements at Gran Sasso, Modane, Canfranc, Boulby as proposed in JRA1 (ILIAS). On the transparency you can see experimental results which have been compared to simulations. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Comparison of codes MCNP and GEANT4 Neutrons from rock, propagation and detection. Need of a comparison using the same geometry and incident spectrum. Modified GEANT3 and FLUKA Muon-induced neutrons  good agreement. GEANT4 and FLUKA Muon-induced neutrons: yield, spectrum, lateral distribution, and dependence with material. Comparison of different models of the codes. Higher production with FLUKA in most materials. Sea-level neutrons. GEANT4 shows an underproduction. MUSIC, MUSUN, SIAM and FLUKA ? Simulation results with different codes have been also compared. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modifications to codes SOURCES Removal of the 6.5 MeV upper limit for alphas. Add of new cross-section and updated of some cross sections according to data. GEANT3 Correction for photonuclear cross-section. Good agreement with FLUKA results. Note also than some people have been working on modifications of codes. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Task B: Platform, language and structure of the library Web page and ftp-site. Further discussion. For the task B, we should fix the platform, language and structure of the library. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Structure of the library General information about codes and links to code web-site. Modifications to codes. Library of examples utilized by Underground groups. Under password We think that this library should contain information, links, modifications and examples. Of course it will be available only for ILIAS users. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Web page and ftp site The web page for the working group is located at the main JRA1 site http://www.unizar.es/ilias It contains information about the code comparison and “evaluated” results. A code ftp repository containing modified programs and examples. Links to WP1, WP3-4 for data. List of publications. A Web page has been created. This web page and the ftp site will be available in the following weeks. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Further discussion Today is a good opportunity to talk about this subject. We should dynamize the distribution list devoted to simulations. Any comment/ suggestion on the structure of the library will be welcome. We could use the distribution list for this purpose. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Task C: First set of MC codes for relevant background components and instrumentation Alpha, beta and gamma. Muons and neutrons. Other codes. For this task we should agree on a first set of MC codes. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Alpha, beta and gamma background Widely used GEANT4 Advanced example for underground physics Most of the standard codes are quite fair to handle the alfa, beta and gamma interactions. Maybe the most widely used is GEANT4 developed in CERN. In the web page and in the documentation you can even find an Advanced example for underground physics 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Neutron background Measurement n at lab Rate and spectrum for 238U fission and (a,n) n flux and spectrum at lab counting rates at detector rock activity For neutrons the situation is more complicated. Let us consider the case of neutrons coming forma radioactivity of the rock: Now we are using SOURCES (form LANL) to compute the rate and spectrum of the fission and (a,n) processes MCNP (TUM, Lyon, Saclay and others) or FLUKA (Sheffield, TUM, Milan, Zaragoza) to simulate the neutron propagation and GEANT4 (Sheffield, RAL, ICL, Zaragoza, Milan) to study the neutron interactions. So we will obtain the n flux and spectrum at lab which could be tested in experimental measurements. It is necessary again to use MCNP and GEANT (propagation and interaction) to calculate the counting rates at detector (new test). Theory Calculation SOURCES FLUKA MCNP GEANT4 FLUKA MCNP GEANT4 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Muon induced neutron background Measurement muons at lab Flux and spectrum for muons under-ground Flux and spectrum of induced neutrons counting rates at detector muons Calculation MUSIC, MUSUN, SIAM, FLUKA For neutrons induced by muons we are using even more codes. Given a sea-leel flux of muons, the codes MUSIC, MUSUN, SIAM and FLUKA calculate the underground flux of muons. Here we should carried out experimental measurements at lab. FLUKA (and probably GEANT4) can be used to get the flux and spectra of induced neutrons known the muon flux (or vice versa). Finally, again MCNP, FLUKA and GEANT4 for the transport in materials and interactions in the detector. FLUKA modified -GEANT3 GEANT4 MCNP GEANT4 GEANT3 FLUKA 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Other codes Cosmogenic induced activity IDEA web- page Another source of internal contamination is the induced activity by sea-level cosmic rays (cosmic neutrons mainly) which could take years to disappear . The study of these codes has been undertaken inside the JRA2 (IDEA) by the WP3-B1. http://idea.dipscfm.uninsubria.it/ 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Milestones and deliverables of the first year First “test” of MC libraries. ftp repository. Technical Report. Publications Let’ s come back to the milestones and deliverables we agreed for this first year. As I have shown you we have achieved the objectives of the WP for the year.

First “test” of MC library We have identified the tasks for which each code is suitable. We have compared simulations results of different codes . We have reported on problems, bugs and open questions. Important meeting held in Edinburgh last September. A Mid-term report was sent to JRA1 coordinator. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) FTP repository We accept any suggestion about this site. Please send a message asking for the password to luzon@unizar.es 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Technical report A technical report is under preparation. We have examined Physic models (specially for neutrons and muons): processes, data libraries, energy ranges, … Geometry capabilities. Biasing options (to save CPU time) Energy detection capabilities: nuclear recoil? Support, availability of code source … 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Publications H. Wulandari et al. Proceedings of IDM2002. G. Chardin and G. Gerbier. Proceedings of IDM2002. V. Kudryavtsev et al. Proceedings of IDM2002 (York, UK, 2-6 September 2002), p. 476. V. A. Kudryavtsev et al. NIM in Phys. Res. A, 505 (2003) 688. G. Gerbier et al, Nucl. Phys. B (Proc. Suppl.) 138 (2005) 59-64. S. Cebrian et al, Nucl. Phys. B (Proc. Suppl.) 138 (2005) 65-67. H. Wulandari. PhD thesis – TUM (2003). H. Wulandari et al, hep-ex/0401032 J. M. Carmona et al. Astr Phys. 21 (2004) 523.. M. J. Carson et al. Astr. Phys. 21 (2004) 667. H. Wulandari et al, Astrop. Phys 22 (2004) 313. P. F. Smith et al, Astrop.Phys. 22 (2004) 409. As you can see after the publications list up to now, there is a great activity on the field. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) H. M. Araujo et al, submitted to Nucl. Instrum. Meth. A, hep-ex/0411026 G.Luzón. Talk at IDM-2004; see IDM-2004 web-site. H. Mengetti. Talk at IDM-2004; see IDM-2004 web-site. C. Cozzini. Talk at IDM-2004; see IDM-2004 web-site. J. McMillan. Talk at IDM-2004; see IDM-2004 web-site. H. Wulandari . Talk at IDM-2004; see IDM-2004 web-site. S. Scholl. Talk at IDM-2004; see IDM-2004 web-site. M. Bauer. Talk at IDM-2004; see IDM-2004 web-site. M. Carson. Talk at IDM-2004; see IDM-2004 web-site. J. Davies. Talk at IDM-2004; see IDM-2004 web-site. H. Araújo and V. Kudriavtsev. Talk at IDM-2004; see IDM-2004 web-site. V. Kudriavtsev. Talk at LBT (SNO). As you can see after the publications list up to now, there is a great activity on the field. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Plan of work for the next months Comparison to experimental data. Benchmarks. Next simulation meeting JRA1(WP2)-N3(BSNS).

Comparison experimental data To compare, if possible, simulation results of each code with available experimental data. To use the JRA1-WP1, WP3-4 data on background contributions to compare with codes simulations. 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Inputs for the simulations: from JRA1/N2 Measurement n at lab Measurement n at lab Rate and spectrum for 238U fission and (a,n) n flux and spectrum at lab counting rates at detector rock activity rock activity Theory Calculation SOURCES MCNP GEANT4 MCNP GEANT4 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Outputs from the simulations: to check n flux and spectrum before detector Measurement n at lab Rate and spectrum for 238U fission and (a,n) Rate and spectrum for 238U fission and (a,n) n flux and spectrum at lab n flux and spectrum at lab counting rates at detector counting rates at detector rock activity Theory Calculation SOURCES MCNP GEANT4 MCNP GEANT4 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Outputs from the simulations: to check n yields Measurement muons at lab n flux and spectrum before detector Flux and spectrum for muons under-ground Flux and spectrum for muons under-ground Flux and spectrum of induced neutrons Flux and spectrum of induced neutrons counting rates at detector counting rates at detector muons Calculation MUSIC, MUSUN, SIAM, FLUKA FLUKA modified -GEANT3 GEANT4 MCNP GEANT4 GEANT3 FLUKA 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Modane_Jan05 Gloria Luzón (LSC) Benchmark Could we fix a few benchmarks? The distribution list can be used with this goal. Group Process codes Exp. LSC (n, 2n) in shielding materials FLUKA, GEANT CAST (TPC chamber) … 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)

Next meeting on simulation activities. To be held in Valencia (SPAIN) in March. Fixed date? 24/02/2019 Modane_Jan05 Gloria Luzón (LSC)