Presentation on theme: "WALTER GREINER RECOMMENDATIONS Programme Advisory Committee for Nuclear Physics 31st Meeting 25–26 January 2010."— Presentation transcript:
WALTER GREINER RECOMMENDATIONS Programme Advisory Committee for Nuclear Physics 31st Meeting 25–26 January 2010
Preamble JINR Vice-Director M. Itkis informed the PAC about the Resolution of the 106th session of the Scientific Council (September 2009) and the decisions of the Committee of Plenipotentiaries (November 2009). The PAC is pleased to note the decision of the Committee of Plenipotentiaries (CP) to increase the JINR budget by 20.7% in The CP also emphasized the importance of the annual increase of the budget in 2010–2016, planned according to the budget forecast approved by the CP, for achieving the milestones of the development strategy for the next seven-year period.
Results of the implementation of the Programme of the Scientific Research and Development of JINR (2003–2009) and the JINR Programme of Nuclear Physics Research proposed for 2010–2012 The PAC congratulates the Directorate and the international staff of JINR on the complete and successful realization of the previous seven-year scientific programme and highly appreciates the valuable contributions to the advancement of science and technology at the world level that have been achieved as part of this programme. The PAC takes note of the report presented by JINR Chief Scientific Secretary N. Russakovich and endorses the proposed main lines of the JINR Programme of Nuclear Physics Research for the period 2010–2012 in accordance with the new seven-year JINR development plan.
IREN (Источник Резонансных Нейтронов) First Experiments Radiation resistance of the materialsRadiation resistance of the materials Extracted neutron beam parameters testingExtracted neutron beam parameters testing Neutron Resonance Capture Analysis (NRCA) of elemental/isotopic compositionNeutron Resonance Capture Analysis (NRCA) of elemental/isotopic composition 117mSn production with photonuclear reactions117mSn production with photonuclear reactions
Accelerated electrons average energy – 30 MeV Peak current – 2.8 A;Peak current – 2.8 A; Pulse duration – 100 ns;Pulse duration – 100 ns; Repetition rate – 50 Hz;Repetition rate – 50 Hz; Neutron yield – n/sNeutron yield – n/s IREN-1 parameters by the end of 2009
Neutron flux density at 10 m flight path
IREN vs IBR-30 (Ta (n, )) The PAC heard with interest the report on the first test measurements performed at the improved IREN-1 neutron source. The achieved energy resolution of the facility is good and permits reaching the new higher level of neutron resonance identification.
IREN 1-st stage outlook for Upgrade of the RF power system with new klystron. This will result in RF power increase and duplicate electron energy with neutron yield n/s; 2011–2012: further upgrade of the RF power system and starting operation with the second accelerating section. This will provide the designed 200 MeV electron energy and beam power about 5.5 kW with neutron yield about n/s; 2012–2016: upgrade of the klystron modulators in order to reach the designed value of the repetition rate –– 150 Hz. Design and construction of a uranium non-multiplying target. Reaching of the beam power at the level of 10–15 kW and neutron yield at the level of several units of n/s, which will position IREN facility in line with the most intense resonance neutron sources of such type.
Recommendation The PAC recommends the acceleration of the upgrade of IREN-1 to rapidly reach the higher intensity of the source and to make it really comparable with powerful neutron sources in Europe. It also recommends that additional funding be provided for supplying the necessary equipment for the next phase of IREN and its full completion as well as for modernization of the experimental instruments.
Experiments on the synthesis of element 117
The PAC heard with interest the report on the results of the experiment dedicated to the synthesis of element 117 in the 48 Ca+ 249 Bk reaction. The PAC congratulates the staff of the Flerov Laboratory on the discovery of element 117 and new isotopes of elements 115, 113, 111, 109, 107, and 105. The discovery of chains of two neighboring isotopes emphasizes the importance of the odd-even and odd-odd effect for such heavy nuclei. It is in fact especially interesting that the odd-odd chain (3n channel) neighboring to the odd-even chain (4n channel) is twice longer (6 α particles ). odd-odd odd-even
Production of neutron-rich SHE in low-energy collisions of heavy actinide nuclei Zagrebaev & Greiner, PRC, 2008
The PAC suggests considering, during the modernization phase of the U400 cyclotron complex, the possibility to develop a uranium beam of large intensity (~10 12 p/s). This will allow the exploration, in further perspective, of alternative pathways to extend the nuclear chart towards even heavier and longer living nuclei. The PAC looks forward to further discussions of the status of the operating basic facilities and of projects of new experimental physics instruments of FLNR at its future meetings. Recommendation
MA ss S eparator of H eavy A toms The proposed setup is a combination of the so-called ISOL method of synthesis and separation of radioactive nuclei with the classical method of mass analysis, allowing mass identification of the synthesized nuclides in the wide mass range. Status on the MASHA set-up General ion-optical parameters Range of energy variation, kV15-40 Range of Br variation, Tm Mass acceptance, %+/-2.8 Angular acceptance, mrad+/-14 Diameter the ion source exit hole, mm 5.0 Horizontal magnification at F1/F2 0.39/0.68 Mass dispersion at F1/F2, mm/%1.5/39.0 Linear mass resolution at F175 Mass resolution at F PAC for Nuclear Physics, 31 st meeting, January 2010
Mass-spectrometer MASHA at the beam line of the cyclotron U-400M New beam line with low energy of the U-400M was built Mass-spectrometer mounted at the new beam line Hot catcher is ready Focal plane detector system is ready Start of test and first experiments – April of 2010 Status of the mass-spectrometer MASHA PAC for Nuclear Physics, 31 st meeting, January 2010
The PAC discussed in detail the current status and prospects of the MASHA spectrometer presented at this meeting. The PAC recognized with interest the plans for developing a gas ion-catcher in addition to the existing ISOL type ion source. Status on the MASHA set-up Mass spectrum of Kr isotopes: Total efficiency – 47% Mass resolution Mass measurement accuracy – 1.3x10-5
First experiments: Start of test and first experiments – April of 2010 Mass identification of 112 и 114 elements synthesized at the reactions 242 Pu( 48 Ca,3n) (0.5 s, a) –> (4 s, E a = 9.95 MeV) 244 Pu( 48 Ca,3-4n) (2.7 s, a 9.82 MeV) –> (4 s,E a = 9.95 MeV) Mass identification of 113 elements synthesized at the reaction 243 Am( 48 Ca,3n) (80 ms,E a = 10.5 MeV) -> (0.5 s,E a = 10.0 MeV, (analog of Tallium) Recommendation The PAC strongly supports the intention of the FLNR Directorate to start experiments with the MASHA mass spectrometer in The PAC recommends the installation of a gas ion-catcher and optimization of its properties for use at the MASHA set-up.
Status report on the GABRIELA set-up The PAC heard the current status and prospects of the VASSILISSA separator and the GABRIELA set-up (7 Ge detectors and a large number of Si strip detectors), based on the joint JINR-IN2P3 collaboration programme dedicated to the study of nuclear structure and nuclear reaction mechanism of heavy nuclei and superheavy elements. The scientific programme started in 2004, and 5 full-scale experimental campaigns (1 month of beam time per year) were completed with high-intensity beams of 48 Ca, 22 Ne, and 40 Ar. The ongoing programme will benefit from the upgrade of the VASSILISSA separator started in 2008 from modified Ge detectors with higher multiplicity as well as from the use of actinide targets in asymmetric systems. The PAC appreciates the considerable progress achieved in the course of modernization of the VASSILISSA separator being performed in close collaboration with IN2P3.
Experimental set-up VASSILISSA + ( α, )-detector array Experimental hall of the U400 cyclotron
Experimental methods: Focal plane detector assembly GABRIELA: Gamma Alpha Beta Recoil Investigation with the Electromagnetic Analyser
21 22 Ne Pu U218 Lr255 Summary of results and on-going analysis Th Ti Pb Rf256 Rf257
Velocity filter for asymmetric combinations (modernization of VASSILISSA) High transmission for asymmetric combinations (beams of 12 C, 14,15 N, 16,18 O, 20,22 Ne) movable plates of electrostatic deflectors Availability for symmetric combinations ( 136 Xe Xe 272 Hs*) 50 cm long plates, high electrostatic field strength For asymmetric combinations – Increase of the electrostatic deflectors aperture Movable plates
Future plans: Advantage of Dubna 244 Md 245 Md 243 Fm 244 Fm 246 Md 247 Md 245 Fm 246 Fm 248 Md 249 Md 247 Fm 248 Fm 250 Md 251 Md 249 Fm 250 Fm 252 Md 253 Md 251 Fm 252 Fm 254 Md 255 Md 253 Fm 254 Fm 256 Md 257 Md 255 Fm 256 Fm 258 Md 259 Md 257 Fm 258 Fm 260 Md 261 Md 259 Fm 260 Fm 249 Lr 250 Lr 248 No 249 No 251 Lr 252 Lr 250 No 251 No 253 Lr 254 Lr 252 No 253 No 255 Lr 256 Lr 254 No 255 No 257 Lr 258 Lr 256 No 257 No 259 Lr 260 Lr 258 No 259 No 261 Lr 262 Lr 260 No 261 No 263 Lr 264 Lr 262 No 263 No 251 Db 252 Db 250 Rf 251 Rf 253 Db 254 Db 252 Rf 253 Rf 255 Db 256 Db 254 Rf 255 Rf 257 Db 258 Db 256 Rf 257 Rf 259 Db 260 Db 258 Rf 259 Rf 261 Db 262 Db 260 Rf 261 Rf 263 Db 264 Db 262 Rf 263 Rf 265 Db 266 Db 264 Rf 265 Rf 253 Bh 254 Bh 252 Sg 253 Sg 255 Bh 256 Bh 254 Sg 255 Sg 257 Bh 258 Bh 256 Sg 257 Sg 259 Bh 260 Bh 258 Sg 259 Sg 261 Bh 262 Bh 260 Sg 261 Sg 263 Bh 264 Bh 262 Sg 263 Sg 265 Bh 266 Bh 264 Sg 265 Sg 267 Bh 268 Bh 266 Sg 267 Sg 78 Pt, 79 Au, 80 Hg, 81 Tl, 82 Pb, 83 Bi targets – « cold fusion » 90 Th, 92 U, 94 Pu, 95 Am, 96 Cm targets – « hot fusion » Present limits 3 -5 nb for decay nb for prompt => Acces to less neutron-deficient nuclei 263 Sg 262 Sg
Recommendation The PAC strongly supports the approval of the proposed upgrade of the GABRIELA and VASSILISSA complex with high priority
Visit to FLNR U400MU400U200 IC-100 MT-25 DRIBs in Gallery U400MU400U200 IC-100 MT-25 DRIBs in Gallery
The PAC members are grateful to the Directorate of the Flerov Laboratory of Nuclear Reactions for the organization of a visit to the laboratory to see the experimental equipment, in particular the accelerator complexes. Great changes in the appearance were noted in many sections of this laboratory. The good status of the equipment and the good organization of the research at FLNR helped very much the members of the PAC to understand the excellent results produced in the laboratory, demonstrated very recently by the synthesis of the new element 117.
Standard 3 GWth reactor (ВВЭР-1000) Antineutrino yield /s / 4 Antineutrino yield /s / 4 New project DANSS Detector of the Reactor ANtineutrino based on Solid State Plastic Scintillators The PAC heard the proposal on the project DANSS whose goal is to develop and build a solid scintillator-based antineutrino detector. The PAC was pleased with the comprehensive presentation and the quality of the proposal description provided well in advance.
Detection of the reactor neutrino would allow: Measure the actual reactor power (N ν ) Deduce the actual fuel composition (E ν ) Weak (ν-e) cross-section On-line reactor monitoring (tomography?) – especially important in view of the future FBR (with longer life-time and less studied) Non-proliferation (prevent unauthorized extraction of 239 Pu)
Detection idea: Inversed Beta-Decay ) e+e+ (n, ) 30-50μs (from 2.6) to 8 MeV Local burst The burst spread in space.
Segmental solid plastic scintillator (2500 cells) Sensitive volume=1 m 3 Cu (carriage frames = -shield) Pb ( -shield) CH 2 + B (n-shield) Plast. scnt. (µ-shield) DANSS
Recommendation The PAC strongly recommends the approval of the DANSS project with high priority to be implemented under the theme Non-accelerator Neutrino Physics and Astrophysics.
Scientific report Study of the nuclear fusion reactions in a pt system with the muon catalyzed fusion method The PAC heard a scientific report on the theory of muon catalyzed pt fusion. This process was studied extensively at PSI in the 1980s, but the e+e- channel was missed which would clarify the strength of the E0 transition and would shed light on the reaction mechanism of four-body systems.
Possible muon-catalyzed fusion processes in a triple mixture of protium, deuterium and tritium; Cp, Cd, Ct are the respective concentrations, multiplied by the density (relative to liquid hydrogen density, LHD).
Recommendation The PAC recommends the development of an experimental project to study pt fusion by the Mu-CATALYSIS collaboration (JINR Dubna, VNIIEF Sarov, Delft University, INP Cracow, ITEP Moscow).
Poster session The PAC was pleased with the presentations of new interesting results in intermediate energy physics obtained in the ANKE and EDELWEISS experiments and in the theoretical investigations of alpha-cluster and dinuclear models. The PAC congratulates the young physicists for their results, the demonstrated ability to work in top-teams of nuclear physics, and encourages them to continue their activities.
Next meeting of the PAC The next meeting of the PAC for Nuclear Physics will be held on 17–19 June Its tentative agenda will include: Reports and recommendations on themes and projects to be completed in 2010 Consideration of new projects Poster presentations of new results and proposals by young scientists in the field of nuclear physics research Reports dedicated to the 70th anniversary of the discovery of spontaneous fission