Recommendations of the Programme Advisory Committees PAC for Nuclear Physics (16–17 June 2011) Walter Greiner

Agenda I. Implementation of the recommendations of the previous PAC meeting W.Greiner II. Information on the Resolution of the 109th session of the JINR Scientific Council (February 2011) and on the decisions of the JINR Committee of Plenipotentiaries (March 2011) M. Itkis III. Experiments at the IREN facility and concrete plans for its upgrade under the 7-year plan for JINR development V. Shvetsov IV. Possibility for the production and study of heavy neutron-rich nuclei formed in multi- nucleon transfer reactions V. Zagrebaev V. Present status of the GERDA project A. Smolnikov VI. Status of the FASA-3 project (“Nuclei multifragmentation at Nuclotron relativistic beams”) and its further continuation V. Karnaukhov VII. Progress of the BECQUEREL project P. Zarubin VIII. Development of the JINR educational programmes S. Pakuliak IX. Consideration of poster presentations of new results and proposals by young scientists of FLNR and FLNP in the field of nuclear physics research X.Scientific reports “New results of the synthesis of element 115 in the reaction 243 Am+ 48 Ca” V. Utyonkov “Massive neutrinos in nuclear processes” F. Šimkovic

I.Preamble The members of the PAC extended warm congratulations to Professors M. Itkis and Yu. Oganessian on the award of the 2010 State Prize of the Russian Federation in science and technology for the discovery of a new region of stability of superheavy elements. This prestigious award points again to the outstanding achievements of the Flerov Laboratory of Nuclear Reactions in the field of synthesis of superheavy elements. I also congratulate the staff of the Institute and Flerov Laboratory of Nuclear Reactions with IUPAP and IUPAC recognition of the opening 114 and 116 elements.

Scientific program for the IREN: II. Experiments at IREN and plans for its upgrade (V.Shvetsov) Scientific program for the IREN: Nuclear data Nuclear data Resonance neutrons induced fission; Resonance neutrons induced fission; Photonuclear reactions; Photonuclear reactions; Gamma and neutron activation analysis; Gamma and neutron activation analysis; Neutron Resonance Capture Analysis (NRCA); Neutron Resonance Capture Analysis (NRCA); Educational program; Educational program;

Nuclear data accuracy. Influence on: k eff ; k eff ; Reactivity swing during burnup; Reactivity swing during burnup; Doppler and coolant void reactivity coefficients; Doppler and coolant void reactivity coefficients; Isotopes concentration in the spent fuel and heat release; Isotopes concentration in the spent fuel and heat release; Radiotoxicity (long time after discharge); Radiotoxicity (long time after discharge); Neutron emission during cooling time; Neutron emission during cooling time;

G. Leinweber et al., Nucl. Sci. Eng., 154 (2006) 256 V.N. Shvetsov et al. (2010) IREN, neutron yield /s 152 Gd % 154 Gd % 155 Gd % 156 Gd % 157 Gd % 158 Gd % 160 Gd % nat Gd (n,  ) dt= 100ns  t mes = 14h40’ dt= 40 ns t mes = 19h00’ Sample: m g = g size: 11.2 x 14.5 cm 2  : g/cm 2 d: 1.35mm IREN, Dubna f = 25 Hz I e = 2A; t e =100ns L = 58.6m Nuclear data at IREN– first measurements with Gd nat RPI Linac, neutron yield /s

Sternberg Astronomical Institute, Moscow University Sample: settlement collected on the bottom of streams from mountain glaciers, 270 g. Fe content – 12 g Accuracy 15% Cosmic objects Liquid scintillator detector Six 35 l sections The detector length is 60 cm. Diameter of the central channel 28 cm. 60 m flight path Neutron Resonance Capture Analysis

Some facts and figures for 2011 IREN operated more than 400 hours for experiment; IREN operated more than 400 hours for experiment; Reports on nuclear data joint program have been presented by N.Janeva at NEMEA conference (Cracow, 2010) and V.Shvetsov at ISINN (Dubna, 2011); Reports on nuclear data joint program have been presented by N.Janeva at NEMEA conference (Cracow, 2010) and V.Shvetsov at ISINN (Dubna, 2011); Natural Gd total and capture cross sections measurements are in progress (supported by the grant of Plenipotentiary of Bulgaria); Natural Gd total and capture cross sections measurements are in progress (supported by the grant of Plenipotentiary of Bulgaria); Radiation hardness of Si semiconductor structures: experiments are continued (supported by the grant of Plenipotentiary of Slovak Republic); Radiation hardness of Si semiconductor structures: experiments are continued (supported by the grant of Plenipotentiary of Slovak Republic); Determination of the B content in advanced ceramic nanomaterials (supported by the joint JINR-Belorussia research project and JINR-BRFFI grant); Determination of the B content in advanced ceramic nanomaterials (supported by the joint JINR-Belorussia research project and JINR-BRFFI grant); Experimental program on modeling GEN-IV reactors spectra at IREN facility is under preparation (supported by the joint JINR- Poland research project); Experimental program on modeling GEN-IV reactors spectra at IREN facility is under preparation (supported by the joint JINR- Poland research project);

Experiments at IREN and plans for its upgrade The PAC heard with interest the progress report, presented by V. Shvetsov, on the experimental programme carried out in Phase 1 of the IREN facility and on the plans for the development of the source itself as well as on the experimental and methodological research. The PAC considers the plans of the Frank Laboratory of Neutron Physics concerning the speed-up in bringing the parameters of the IREN source up to highest possible standards of equivalent facilities to be realistic, and acknowledges the importance of doing so for the realization of the JINR scientific programme and for attracting specialists from JINR Member States. Recommendation. The PAC recommends fast-tracking the development of the IREN source and suggests that the JINR Directorate support the FLNP plans concerning the development of IREN and the methodological research base of nuclear and neutron physics.

III. Possibility for the production and study of heavy neutron-rich nuclei formed in multi- nucleon transfer reactions (V. Zagrebaev)

Transfermium elements (1)no more alpha-decays ! (2)problem of Z identification

Multi-nucleon transfer reactions as a method for synthesis of heavy neutron rich nuclei Stop in gas with subsequent resonance laser ionization as a method for extracting required reaction products (with a given Z value)

The setup consists of the following elements - front end system including: gas cell, system for extraction of the cooled ion beam, electrostatic system for final formation and acceleration of the ion beam - laser system - mass-separator - system for delivery and cleaning of the buffer gas inside the gas cell, - vacuum system, - high voltage and radio frequency units, - diagnostic and control systems for the ion beam.

Schematic view of the setup for resonance laser ionization of nuclear reaction products stopped in gas

Possibility for the production and study of heavy neutron-rich nuclei in multi-nucleon transfer reactions The PAC discussed the proposal of the Flerov Laboratory, presented by V. Zagrebaev, on the synthesis of heavy neutron rich nuclei formed in low-energy multi-nucleon transfer reactions. The use of this method opens a new field of research in low-energy heavy-ion physics, namely, the production and study of new neutron-rich heavy nuclei playing a key role in the r-process of nucleosynthesis. The development of an experimental set-up based on the method of stopping reaction fragments in gas and on their subsequent selective resonance laser ionization is proposed. With such a method atoms of required elements can be selected. Because of the capability of selecting ions of specific atomic numbers, this set-up can also be employed in other studies, like the unknown charge distribution of the products of quasi-fission. The PAC emphasizes that the proposed experimental method is feasible. Recommendation. The PAC strongly recommends starting to work on the details of this proposal within the Flerov Laboratory right away.

IV. Status of the GERDA experiment (A.Smolnikov) GERDA: the GERmanium Detector Array to search for Neutrinoless Double Beta Decay The GERDA collaboration: 90 physicists / 14 institutions / 6 countries

2  : (A,Z)  (A,Z+2) + 2e  e 0  : (A,Z)  (A,Z+2) + 2e -  L=0  L=2 Double beta decay

The GERDA project is based on using very low background High-Purity-Germanium (HPGe) detectors. HPGe detector fabricated from germanium enriched in 76 Ge isotope (up to 86 %) is simultaneously the ββ decay source and the 4π detector. The advantages of such type experiments (in comparison with the other types) are due to: 1) the excellent energy resolution (3 кэВ at 2 MeV), 2) the high purity of Ge crystals (very low intrinsic background), 3) and the high signal detection efficiency (close to 100%). Disadvantages: 1)not the highest ββ–transiton energy for 76 Ge: Q  =2039 keV (in comparison with the more promising isotopes, such as Mo-100, Nd-150,Ca-48) 2) only one characteristic of ββ decay - sum energy of two electrons – is possible to detect. Nevertheless, up to now such type of experiments are the most sensitive tools in searching for (0vββ)-decay.

Moreover, the part of H-M Collaboration, after additional data treatment, claimed the presence of an excess of events in ROI, which they interpreted as the evidence for  (0 ) observation with the best fit T 1/2 = 1.2  y, | m ee | = 0.44 eV H.V. Klapdor-Kleingrothaus, A. Dietz, I.V. Krivosheina, O. Chkvorets, NIM A 522 (2004) So far the Best Limits on (0vββ)-decay half-life 1.9  y and 1.6  y, which correspond to | m ee | < eV, have been obtained with HPGe detectors in the predecessor experiments Heidelberg-Moscow & IGEX with using Enriched Germanium (86% in 76 Ge, Q  =2038,5 keV )

Liquid Ar cryostat: Shielding, cooling of detectors Water tank instrumented with PMTs: Shielding, Cherenkov muon-veto Clean room: Detector handling Lock system: Detector insertion Phase I detector array Cu shield The main conceptual design of the GERDA experiment is to operate with “naked” HPGe detectors (enriched in Ge-76) submerged in high purity liquid argon supplemented by a water shield. Located at LNGS, Italy GERDA: the GERmanium Detector Array Neutrinoless Double Beta Decay Experiment 3400 m w.e.

GERDA will probe Majorana nature of neutrino with sensitivity at GERDA phase I : with background 0.01 cts / (kg ٠ keV ٠ y) ► to scrutinize KKDC result within 1 year GERDA phase II : with background 1 cts / (ton ! ٠ keV ٠ y) ► to cover the degenerate neutrino mass hierarchy ( < 0.08 – 0.29 eV ) phase III : world wide GERDA –MAJORANA collaboration background 0.1 cts / (ton ٠ keV ٠ y) ► to cover the inverted neutrino mass hierarchy ~10 meV KDKC claim: [ ] eV Expected sensitivity of the GERDA experiment

Nearest plans To complete the GERDA veto system the assembly of 40 plastic scintillator modules produced in JINR will be installed on top of the GERDA set up and integrated into the total hardware and software systems –June 17, Deploying first string with 3 enriched in Ge-76 naked detectors- July, As soon as the optimal operation parameters are determined the physics data taking with all GERDA detectors enriched in 76 Ge (18 kg in total). – End of summer After completion of the 42 Ar investigations the R&D program for the next GERDA phases will be continued in the LArGe test facility with a string of several BEGe (Broad-Energy Germanium) Phase-II detectors. In the second part of 2011 GERDA collaboration is going to order 30 BEGe detectors from 76 Ge (about 25 kg of 76 Ge in total) and start to equip, test and prepare these detectors for Phase-II.

Status of the GERDA project The PAC heard with great interest the report, presented by A. Smolnikov, on the status of the GERDA project aimed at the search for the neutrinoless double-beta decay using 76 Ge diodes placed in liquid argon. The expected results will sufficiently improve the present knowledge about the nature of neutrino properties related to physics beyond the Standard Model. Following the successful realization of all phases, the expected sensitivity of the GERDA project can reach the region of the Majorana-electron-neutrino mass of about 10 meV and cover the inverted hierarchy region. The GERDA collaboration, with considerable participation of the JINR team, finished the installation of the experimental set up in the deep underground laboratory at LNGS (Italy) and is already starting the first commissioning runs. Next steps will be the operation with all available Ge detectors produced from 76 Ge-enriched material. Recommendation. The PAC recognizes the fundamental importance in neutrino physics of searching for the neutrinoless double-beta decay of 76 Ge and recommends continuation of the GERDA project with high priority.

(Hot Nuclei and Phase Transitions - ) V. Status of the FASA-3 project (Hot Nuclei and Phase Transitions - V. Karnaukhov )

FASA experimental results

VI.Progress of the BECQUEREL (P.Zarubin)

Experimental hall 1B Experimental hall 205 Experimental hall NUCLOTRON – 6 GeV/n SYNCHROPHASOTRON CO2 laser

V. Status of the FASA-3 project The PAC appreciated the status report of the FASA-3 project (“Nuclei multifragmentation at Nuclotron relativistic beams”) presented by V. Karnaukhov. The experiments performed by the FASA collaboration were successful. New data for the properties of the very hot nuclei were obtained. VI. Progress of the BECQUEREL project The PAC heard the report, presented by P. Zarubin, on the progress of the BECQUEREL project for the study of the coherent dissociation of a family of light nuclei, with great interest. Statement. Since it is known that both the FASA-3 and BECQUEREL projects are coming to an end by 2011, the PAC advises advises these groups to prepare a joint project to be presented at the next PAC meeting.

VII. Development of the JINR educational programmes (S. Pakuliak) Goals of the JINR educational program are developing and proper functioning of the system of training of young scientists for the member-states and the Institute itself. “The whole Institute should become a big physical practicum for the Universities of the member- states.” A.N. Sisakian

UC

Development of the JINR educational programmes The PAC heard with interest the report on the development of JINR educational programmes presented by S. Pakuliak. Recommendation. The PAC recommends that the JINR Directorate support the advanced training programme with modern educational and scientific equipment.

VIII. Scientific reports New results of the synthesis of element 115 in the reaction 243 Am+ 48 Ca V. Utyonkov Massive Neutrinos in Nuclear Processes F. Šimkovic

New results of the synthesis of element 115 in the reaction 243 Am+ 48 Ca Target thickness mg/cm 2 E lab (MeV) E exc (MeV) Beam dose x Number of chains

New results of the synthesis of element 115 in the reaction 243 Am+ 48 Ca

Discovery of elements 113 and 115 produced in 2003 was confirmed by observation of 21 new decay chains originating from , the product of the 3n-evaporation channel of the reaction 243 Am+ 48 Ca. Decay properties of all the six nuclei , , 280 Rg, 276 Mt, 272 Bh, and 268 Db synthesized in 2003 are in full agreement with those measured in the recent experiments. Excitation function of the reaction 243 Am+ 48 Ca was measured at three lower projectile energies. Discovery of element 117 was confirmed by registration of the decay chain of which was produced for the first time in the reaction 249 Bk( 48 Ca,4n) as the descendant nucleus of The isotope was synthesized in two cross bombardments.

New results of the synthesis of element 115 The PAC highly appreciated the report “New results of the synthesis of element 115 in the reaction 243 Am+ 48 Ca” presented by V. Utyonkov. The PAC congratulates the FLNR staff on the new interesting results concerning the synthesis of element 115 and especially on the observation of the decay chain of the isotope in the 2n channel, confirming the data obtained in the reaction 249 Bk( 48 Ca, 4n)

Massive Neutrinos in Nuclear Processes (F. Šimkovic)

Massive Neutrinos in Nuclear Processes F. Šimkovic The PAC heard with interest the report “Massive neutrinos in nuclear processes” presented by F. Šimkovic, and strongly recommends the support of this activity.

IX. Poster session The PAC was pleased with the presentations of new results and proposals by young scientists in the field of nuclear physics research. Two best posters have been selected: “Asymmetric quasifission in reactions with heavy ions” presented by G. Knyazheva and “Microbial synthesis of silver nanoparticles Streptomyces glaucus and Spirulina platensis” presented by I. Zinicovscaia. The PAC recommends them for presentation at the Scientific Council session in September 2011.

X. Next meeting of the PAC The next meeting of the PAC for Nuclear Physics will be held on 26–27 January Its tentative agenda will include: -Reports and recommendations on themes and projects to be completed in Consideration of new projects -Report on the experimental set-ups used in the GDH&SPASCHARM project -Status of the Baikal experiment -Poster presentations of new results and proposals by young scientists in the field of nuclear physics research -Scientific reports