WALTER GREINER RECOMMENDATIONS Programme Advisory Committee for Nuclear Physics 31st Meeting 25–26...
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Transcript of WALTER GREINER RECOMMENDATIONS Programme Advisory Committee for Nuclear Physics 31st Meeting 25–26...
WALTER GREINER
RECOMMENDATIONS
Programme Advisory Committeefor 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 2010.
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 ExperimentsFirst Experiments• Radiation resistance of the Radiation resistance of the
materialsmaterials• Extracted neutron beam Extracted neutron beam
parameters testingparameters testing• Neutron Resonance Capture Neutron Resonance Capture
Analysis (NRCA) of Analysis (NRCA) of elemental/isotopic elemental/isotopic compositioncomposition
• 117mSn production with 117mSn production with photonuclear reactionsphotonuclear reactions
Accelerated electrons average energyAccelerated electrons average energy – 30– 30 MeV MeV
• Peak currentPeak current – 2 – 2.8.8 AA;;
• Pulse durationPulse duration – 100 – 100 nsns;;
• Repetition rateRepetition rate – – 5050 HzHz;;
• Neutron yieldNeutron yield – – 88101010 10 nn//ss
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 2010-2016
• 2010 - Upgrade of the RF power system with new klystron. This will result in RF power increase and duplicate electron energy with neutron yield 1012 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 5 1012 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 1013 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
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 48Ca+249Bk 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 (~1012 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
MAss Separator of Heavy
Atoms
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.
Ion source
Detectors
D1 Q1 Q2D2
Q3S1
D3aD3b
S2
Status on the MASHA set-up
General ion-optical parameters
Range of energy variation, kV 15-40Range of Br variation, Tm 0.08-
0.5Mass acceptance, % +/-2.8Angular acceptance, mrad +/-14Diameter the ion source exit hole, mm 5.0Horizontal magnification at F1/F2
0.39/0.68Mass dispersion at F1/F2, mm/%
1.5/39.0Linear mass resolution at F1 75Mass resolution at F2 1150
PAC for Nuclear Physics, 31st meeting, 25-25 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, 31st meeting, 25-25 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
0 20 40 60 80 100 120 140 160 1800
8682 83
84
Strip num ber
0.10
A
0.15
0.05
2 .42 s trip sR = 14 00
K r
Mass spectrum of Kr isotopes:
Total efficiency – 47%
Mass resolution - 1400
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 reactions242Pu(48Ca,3n)287114(0.5 s, a) –> 283112(4 s, Ea= 9.95 MeV)244Pu(48Ca,3-4n)289114 (2.7 s, a 9.82 MeV) –> 283112(4 s,Ea= 9.95 MeV) Mass identification of 113 elements synthesized at the reaction 243Am(48Ca,3n)288115 (80 ms,E a= 10.5 MeV) ->284113(0.5 s,Ea= 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 2010. 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 48Ca, 22Ne, and 40Ar.
• 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
anticoincidence
tflight
= (T2-T
1)
T2
T1
TOF
(E + ECE
)
ER
'Backward - Detector'
'Backward - Detector'
'-Clover-Det.''Stop-Detector'
(E)
CE (ECE
)
(E + ER)
ER
(E) GABRIELA: Gamma Alpha Beta Recoil Investigation with the Electromagnetic Analyser
21
Published results
In progress
Future experiment
Failure from 210Pbtarget
22Ne + 242 Pu
U218
Lr255
Summary of results and on-going analysis
Th216
50Ti + 208Pb
Rf256Rf257
Velocity filter for asymmetric combinations(modernization of VASSILISSA)
High transmission for asymmetric combinations (beams of 12C, 14,15N,16,18O, 20,22Ne) movable plates of electrostatic deflectors
Availability for symmetric combinations (136Xe + 136Xe → 272Hs*) 50 cm long plates, high electrostatic field strength
0
1
2
3
4
5
6
7
8
9
10
11
12
Target W heel
Quadrupole Lenses I
Quadrupole Lenses II
Beam
Electric Deflector I
E lectric Deflector II
M agnetic Deflector II
M agnetic Deflector I
Beam Stop
Tim e of Flightdetector
Position-sensitivedetector array Magnetic
Deflector III
For asymmetric combinations – ♦ Increase of the electrostatic deflectors aperture
Movable plates
Future plans: Advantage of Dubna
244Md
245Md
243Fm
244Fm
246Md
247Md
245Fm
246Fm
248Md
249Md
247Fm
248Fm
250Md
251Md
249Fm
250Fm
252Md
253Md
251Fm
252Fm
254Md
255Md
253Fm
254Fm
256Md
257Md
255Fm
256Fm
258Md
259Md
257Fm
258Fm
260Md
261Md
259Fm
260Fm
249Lr
250Lr
248No
249No
251Lr
252Lr
250No
251No
253Lr
254Lr
252No
253No
255Lr
256Lr
254No
255No
257Lr
258Lr
256No
257No
259Lr
260Lr
258No
259No
261Lr
262Lr
260No
261No
263Lr
264Lr
262No
263No
251Db
252Db
250Rf
251Rf
253Db
254Db
252Rf
253Rf
255Db
256Db
254Rf
255Rf
257Db
258Db
256Rf
257Rf
259Db
260Db
258Rf
259Rf
261Db
262Db
260Rf
261Rf
263Db
264Db
262Rf
263Rf
265Db
266Db
264Rf
265Rf
253Bh
254Bh
252Sg
253Sg
255Bh
256Bh
254Sg
255Sg
257Bh
258Bh
256Sg
257Sg
259Bh
260Bh
258Sg
259Sg
261Bh
262Bh
260Sg
261Sg
263Bh
264Bh
262Sg
263Sg
265Bh
266Bh
264Sg
265Sg
267Bh
268Bh
266Sg
267Sg
78Pt,79Au,80Hg,81Tl,82Pb,83Bi targets – « cold fusion »
90Th, 92U, 94Pu, 95Am, 96Cm targets – « hot fusion »
100
101
102
103
104
105
106
107
146 148 150 152 154 156 158 160
Present limits ≥ 3 -5 nb for decay≥ 50 - 100 nb for prompt
=> Acces to less neutron-deficient nuclei
263Sg
262Sg
Recommendation
The PAC strongly supports the approval of the proposed upgrade of the GABRIELA and VASSILISSA complex with high priority
Visit to FLNR
U400M U400 U200
IC-100 MT-25 DRIBs in Gallery
U400M U400 U200
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.
StandardStandard 3 3 GWGWthth reactor reactor ((ВВЭР-1000ВВЭР-1000))
Antineutrino yield Antineutrino yield 10102020 /s / /s / 44
New project DANSSDetector 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
(Nν)
•Deduce the actual fuel composition
(Eν)
•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 239Pu)
Detection idea: Inversed Beta-Decay
)
e+
(n,)
30-50μs
(from 2.6) to 8 MeV
Local burst
The burst spread in space
.
Segmental solid
plastic scintillator
(2500 cells)
Sensitivevolume=1
m3
Cu (carriage frames = -shield)
Pb (-shield)
CH2 + B(n-shield)
Plast. scnt.(µ-shield)
DANSSDANSS
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 2010. 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
Thanks for your attention