“reaction studies about the q“reaction studies about the q- … · 2009. 10. 15. · technische...
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Technische Universität München
“Reaction studies about the Q“Reaction studies about the Q--value influencevalue influenceon the production of superheavy elements”on the production of superheavy elements”
Reimar GraegerReimar GraegerSeventhSeventh Workshop onWorkshop on thethe chemistrychemistry ofof thethe heaviestheaviest elementselements
Mainz, GermanyMainz, GermanyOctoberOctober 1111thth -- 1313thth, 2009, 2009
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Technische Universität München
HsHs -- ElementElement 108108
•• TransactinideTransactinide ––group VIII elementgroup VIII element
•• 270270Hs is double magic nucleusHs is double magic nucleuswith closed deformed shellwith closed deformed shellatat Z=Z=108,108, N=N=162162
•• Forms volatileForms volatile tetroxidetetroxide ––HsOHsO44 –– very high yield ofvery high yield ofchemical separation!chemical separation!
•• First synthesized at GSIFirst synthesized at GSI(Darmstadt) in year 1984(Darmstadt) in year 1984208208PbPb((5858FeFe, 1n, 1n))265265HsHs
116
114
110108
104106
112
114
112
HsDs
Sg
Rf
No
150 155 160 165 170 175 180
8
9
10
11
12
Neutron number
118Z-even
even-eveneven-odd
Q
New data
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Technische Universität München
CutoutCutout fromfrom thethe chartchart ofof nuclidesnuclides208Pb(70Zn,1n) 277112
248Cm(26Mg,3-5n) 269-271Hs238U(36S,3-5n) 269-271Hs226Ra(48Ca,3-5n) 269-271Hs
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Confirmation of synthesis ofConfirmation of synthesis of 277277112112S. Hofmann et al., Z. Phys. A354, 229 (1996)S. Hofmann et al., Z. Phys. A354, 229 (1996)
277112
280 s1
273110
110 s2
269Hs
19.7 s3
265Sg
7.4 s4
261Rf
4.7 s5
257No
15.0 s6
11.08
11.45
9.23
(4.60)
8.52
8.34
Hs
1
265Sg
17.1 s2
261Rf
0.85 s3
269Hs
19.188.88
8.90
265Sg
4.4 s2 8.69
8.50
261Rf
2.4 s3
8.50
257No
55.6 s4 8.21
269
ChCh. E. Düllmann et al., Nature. E. Düllmann et al., Nature 418, 859 (2002)418, 859 (2002)
SHIPSHIP @ GSI@ GSISHIPSHIP @ GSI@ GSIFeb 1996Feb 1996Feb 1996Feb 1996
SHIPSHIP @ GSI@ GSIFeb 1996Feb 1996
HassiumHassium::ChemistryChemistrypossiblepossible!!
HassiumHassium::ChemistryChemistrypossiblepossible!!
HassiumHassium::ChemistryChemistrypossiblepossible!!
HsHs--chemistrychemistryMay 2001May 2001
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Technische Universität München
Doubly Magic NucleusDoubly Magic Nucleus 270270HsHsJ. Dvorak et al., Phys. Rev.J. Dvorak et al., Phys. Rev. LettLett.. 9797, 242501 (2006), 242501 (2006)
9.18 - 9.22
269Hs8.91 - 9.039.06 - 9.139.18 - 9.22 8.67 - 8.92
270Hs
8.67 - 8.92 9.23 - 9.30
271Hs
9.02 - 9.169.23 - 9.30
266Sg50ms - 1.6s
SF
263Rf12 s
SF
8.24; 8.29
257No
2.5; 21 s
8.24; 8.29
267Sg0.5 – 4.5 m
8.20; SF
269Hs 270Hs 271Hs11 + 2 7 5 + 1
269Hs 270Hs 271Hs11 + 2 7 5 + 1
2626MgMg ++ 248248CmCm 274Hs*274Hs*
5 new isotopes discovered!5 new isotopes discovered!
261Rf78 s 2.7 s
8.518.29 SF
265Sg7 s 15 s
8.94;8.84;8.76 8.69
July 2008 at FLNR:July 2008 at FLNR:Decay properties forDecay properties for 270270HsHsconfirmed!confirmed!
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Technische Universität München
269,270,271Hs269,270,271Hs2626MgMg ++ 248248CmCm 274Hs*274Hs*
269,270,271Hs269,270,271Hs4848Ca +Ca + 226226RaRa 274Hs*274Hs*
Q =Q = -- 82,2 MeV82,2 MeV
B = 126,9 MeVB = 126,9 MeV
Q =Q = -- 116,7 MeV116,7 MeV
B = 159,1 MeVB = 159,1 MeV
269,270,271Hs269,270,271Hs++ 238238UU 274Hs*274Hs*
Q =Q = -- 153,9 MeV153,9 MeV
B = 187,0 MeVB = 187,0 MeV
BB -- Q = 44,7 MeVQ = 44,7 MeV
BB -- Q = 42,4 MeVQ = 42,4 MeV
BB -- Q = 33,1 MeVQ = 33,1 MeV
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4n4n--channel Excitation functions (channel Excitation functions (270270Hs)Hs)
BBBassBass
E* (CN 274Hs*)
(4n 270Hs)EVREVR == captcapt*P*PCNCN**WWsursurEVREVR == captcapt*P*PCNCN**WWsursur
CNCNCNCNCNCN ~ P~ PCNCN ~ asymmetry~ asymmetry
Above the barrier:Above the barrier:EVREVR ~~
Below the barrier:Below the barrier:EVREVR ~~ ((BBBassBass –– Q) ~ QQ) ~ Q--valuevalue
From Ch. E. Düllmann
Z.H. Liu and J.-D. Bao, Physical Review C 74, 057602 (2006)
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Technische Universität München
Hassium separator experiment at DGFRSHassium separator experiment at DGFRS226226Ra(Ra(4848Ca,Ca, xxnn))274274--xxHsHs
FLNR and TUM collaborationFLNR and TUM collaborationDGFRS @ FLNR, DubnaDGFRS @ FLNR, DubnaJune 2008June 2008 -- August 2008August 2008
November 2008November 2008 -- FebruaryFebruary 20092009
U400U400 cyclotroncyclotron
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Technische Universität München
Experimental setup:Experimental setup:The Dubna GasThe Dubna Gas--Filled Recoil SeparatorFilled Recoil Separator
Beam (Beam (4848Ca)Ca)
Target (Target (226226Ra)Ra)
DipoleDipole
QuadrupolesQuadrupoles
FocalplainFocalplain
C.E. Düllmann et al 2005C.E. Düllmann et al 2005
226Ra
269-271Hs48Ca
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Technische Universität München
Target: 234 g/cm2 226RaO (1st experiment)Targetwheelarea: 36 cm2 362 g/cm2 226RaO (2nd experiment)Backing: 1.5 m Ti
Detector: detection efficiency: = 87%SF ~ 100%
energy resolution: 50-110 keV (FWHM, -particles, FPD)130-310 keV (FWHM, -particles, side)
position resolution: 1.1-1.9 mm ( -particles, FPD)0.6-1.6 mm (SF, FPD)2.0-3.5 mm ( -particles, E > 3 MeV, side)3.4-5.8 mm ( -particles, E < 3 MeV, side)
Yu.Ts. OganessianYu.Ts. Oganessian et alet al., to be published., to be published
Beam: 48Ca @ 0.7-1.1 p A (typical intensities)
Separator efficiency: DGFRS = (40±5)%
226Ra(48Ca, xn)274-xHs: experimental details
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Technische Universität München
Yu.TsYu.Ts.. OganessianOganessian et alet al., to be published., to be published
Target thickness(mg/cm2)
Ebeam (MeV) E* (MeV) Beam dose1018
0.230.36
228.5 34.2-38.1 2.93.3
0.230.36
233.5 38.0-42.5 3.01.1
0.36 240.5 44.0-48.1 2.3
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Technische Universität München
Hassium chemistry experiment at GSIHassium chemistry experiment at GSI238238U(U(3636S,S, xxnn))274274--xxHsHs
UNILAC GSI, DarmstadtUNILAC GSI, Darmstadt30. 04. 200830. 04. 2008 –– 14. 05. 200814. 05. 2008
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Technische Universität München
Hs production and separationHs production and separation
UNILAC GSI DarmstadtUNILAC GSI Darmstadt
3636SS5+5+
EVR‘sEVR‘s
ARTESIAARTESIAtarget wheeltarget wheel
To COMPACTTo COMPACT
He/OHe/O22
Recoil chamber and ovenRecoil chamber and oven
238238UU
Target: 238U3O8 (1.8 mg/cm2, 1.6 mg/cm2, 1.5 mg/cm2)238Umetal (1.0 mg/cm2 each)
Beam: 36S5+ @ 256.4 MeV (lab) (Ityp ~ 350 pnA)
Detector: 2 x 32 PIPS diodes ( E = 50 keV FWHM)
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Technische Universität München
Experimental setupExperimental setup
“COMPACT”“COMPACT”Liquidnitrogencooling
He O2
Membranepump
PTFE capillary
Drying systemRecoilchamber
Oven600 °C
Quartz woolplug
36SCu beamdump
238Utarget Be window
10 % O2
2 x 32 PIPS diodes
Overall efficiency 50 %
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Technische Universität München
• Longitudinal negative temperature gradient isestablished along the thermochromatography(TC) column
• Different species borne by carrier gas areslowed down and deposited at differentpositions (temperatures) in TC columnaccording to their volatilities
• From the adsorption temperature Ta the valueof the adsorption enthalpy Hads can beevaluated
• Standard sublimation enthalpy Hsubl can beevaluated based on the empirical correlation
.
ThermochromatographyThermochromatography
Yiel
d [%
]Te
mpe
ratu
re [
°C]
25
- 150
Distance [cm] 400
TC column
Ta
Gas flow
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Technische Universität München
Vacuum tight channel2x32 PIPS
1x1 cm2
“COMPACT”“COMPACT”
CryoOn-lineMultidetector forPhysicsAndChemistry ofTransactinides
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Technische Universität München
3636S +S + 238238UU 274Hs*274Hs*
HsHs--chemistrychemistry -- May 2008May 2008 -- ResultsResults
EVREVR (4n) = 0,8(4n) = 0,8+2,6+2,6--0,70,7 pbpb
268Hs0.5 s*
9.58*
269Hs9.7 s
8.95, 9.13
270Hs23 s*
8.88
264Sg37 ms
266Sg360 ms
265Sg9 s 16 s
8.85 8.69
261Rf68s 3 s
8.28 8.51
274Hs*CN
4n5n6n
263Rf8 s
271Hs4 s*
9.13, 9.30
3n
267Sg80 s
8.20
09.05.200809.05.200806:22:0606:22:06
23 ms41 / -
24B / -
24T
decay chain E* = 38 MeV E* = 51 MeV
7.08 10-4 3.12 10-3
SF 4.61 10-3 1.67 10-3
SF 1.6 10-2 4.6 10-2
Random rates:t = 300 s (267Sg: T1/2 = 80 s)
8.0 MeV < E < 10.0 MeVESF > 15 MeV
E* = 51E* = 51±±3 MeV3 MeV9.02±0.08
270Hs7.6 s
9.02±0.08
266Sg
284 ms
(Dubna)
05.01.002.9
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Technische Universität München
270Hs23 s*
8.88±0.05
266Sg
350 ms
266Sg23 ms
270Hs9 s*
9.02+0.05-0.1
270Hs7.6 s
9.02±0.08
266Sg
284 ms
270270HsHs summarysummary ofof experimentsexperiments::
2626Mg +Mg + 248248Cm:Cm: 3366S +S + 238238U:U: 4848CaCa ++ 226226Ra:Ra:
* log10T1/2 = a Z (Qa – Ei)-1/2 + b Z +c
A. Parkhomenko, A. SobiczewskiActa Physica Polonica 36, No. 10 (2005)
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Technische Universität München
Excitation function:Excitation function: 238238U(U(3636S,S, xnxn))274274--xxHsHs
EVREVR (4n) = 0,8(4n) = 0,8+2,6+2,6--0,70,7 pbpb
Paper in preparationPaper in preparation
(Errors and limits corresponds to 68% confidence level)
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Technische Universität München
Excitation function:Excitation function: 248248Cm(Cm(2626Mg,Mg, xnxn))274274--xxHsHs
J. DvorakJ. Dvorak et alet al., Phys. Rev.., Phys. Rev. LettLett.. 100100, 132503, 2008, 132503, 2008
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Technische Universität München
Excitation function:Excitation function: 226226Ra(Ra(4848Ca,Ca, xnxn))274274--xxHs @ FLNRHs @ FLNR
PreliminaryPreliminary
EVREVR (4n) = 8,3+(4n) = 8,3+6,76,7--3,73,7 pbpb
Calculations: V. Zagrebaev, W. Greiner, Phys. Rev. CCalculations: V. Zagrebaev, W. Greiner, Phys. Rev. C 7878, 034610, 2008, 034610, 2008Exp. Data:Exp. Data: Yu.TsYu.Ts.. OganessianOganessian et alet al., to be published., to be published
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Technische Universität München
A. GorshkovA. TürlerA. YakushevD. AckermannCh. E. DüllmannE. JägerF. P. HeßbergerJ. KhuyagbaatarJ. KrierD. RudolphM. SchädelB. SchaustenJ. DvorakH. NitscheM. ChelnokovV. ChepiginA. KuznetsovJ. EvenD. HildJ. V. KratzJ. P. OmtvedtF. SamadaniK. NishioQ. Zhi
THANK YOU!THANK YOU!