Title: Results of 226Ra 48Ca Experiment Yu'Tsyganov, Yu'Oganessian, V'Utyonkov, Yu'Lobanov, F'Abdullin, I'S
1Results of 226Ra48Ca ExperimentYu.Tsyganov
Yu.Oganessian V.Utyonkov Yu.Lobanov
F.Abdullin I.Shirokovsky A.Polyakov
V.Subbotin A.Sukhov R.Sagaidak A.Voinov and
JINR (Dubna) LLNL (Livermore) TUM (Muenchen)
INS Vinca (Belgrade) collaboration
Yu.Tsyganov 07 Apr. IOP-2009 Birmingham UK
- Content
- Introduction
- Synthesis of 269-271Hs by TUM group
(briefly properties) - 2) Experiment at U-400 cyclotron using DGFRS
- a) The Dubna Gas Filled Recoil Separator
detection module experiment motivation... - b) Parameters of experiment
- c) Results and discussion
- 3) Summary
- Nearest future experiments predictions of
cross sections
Target wheel mounting
Sci. leader
2270
271
New isotopes
3n/4n ratio
3Experimental setup of TUM group (discovery 270Hs
)
Transport time 3 s
Transport time 1 s
No T1/2 value for 270Hs can be measured because
of missing of EVR signal !
by Dr. Alexandr Yakushev (TUM )
4The Dubna Gas Filled recoil Separator (JINRLLNL
since 2001)
226Ra target design ( six sectors form-
RaO) Foil 1.5 mcm Ti.
GSI RIKEN
.
.
.
Experiment 226Ra48Ca270Hs4n
DGFRS 2008
- Why...
- to check decay properties 270271Hs discovered by
TUM group - to measure cross sections of 34 n reaction
channels ( a) by itself b) as a parameter for
any extrapolations/corrections to Z117-120 )
5DGFRS Detection module
6position windows corresponding to two position
resolutions (2.35 standard deviations
confidence level (c.l.) 0.98).
E9.020.08 MeV T1/27.64.92.2 s the
half-life of the daughter spontaneously
fissioning isotope is 0.280.90.08 s in
agreement with TUM group results (E8.880.05 MeV
for 270Hs and TSF0.360.250.10 s for 266Sg).
233.2 2.8 projectile energy Excitation energy
40.0 2.2 MeV Target 0.23 and 0.36
mg/cm2 (two runs) Beam dose 4.11018 Cross
section 8.3 6.73.3 pb
ltEEVRgt13.00.77 MeV Calculated 13.2 MeV
7Background level
Time intervals between particles and all
preceding ER-like events observed within two ER-
or ER-SF position resolutions (2.35 standard
deviations) are shown. Time intervals for the
nearest ER events assigned to implantation of
270Hs in detectors are shown by arrows. Dash
line shows distribution dN/d(lg10 t) for
T1/27.6 s. Dash-dot line shows linear fit for
random ER-like events.
8But..3n! (they give max channel)
9Summary
Yu.Tsyganov IOP-2009
1) Cross section for the 226Ra48Ca270Hs4n
reaction was measured as about 8.3 pb ( beam
dose 31018 part. ) Decay properties of 270Hs
measured by TUM group are confirmed (in
principle) 2) Both 3n and 5n channel decays
were not detected for the beam doses 6.21018 (
4.2 pb if T1/24s) and 2.31018 ( 5.0 pb )
respectively. 3) Calculations by Adamyan at al.
(PRC 69 (2004) ) do not reproduce in principle
the maximum reaction channel number (3n except
for 4n measured in our experiment) ---------------
--------------------------------------------------
------------------------------------- 4) Cross
section values for the future 243Am 50Ti and
249Cf 50Ti reactions may have of greater values
than ones predicted by W.Greiner V.Zagrebaev
calculations
V.Zagrebaev and W.Greiner calculations