0000000000115448
AUTHOR
O. Thelen
showing 7 related works from this author
"Safe" Coulomb excitation of 30Mg.
2004
We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient $\gamma$ -spectrometer MINIBALL. Using $^{30}$Mg ions accelerated to an energy of 2.25MeV/u together with a thin $^{nat}$Ni target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative de-excitation $\gamma$ -ray yields the B(E2; 0$^{+}_{gs} \rightarrow 2^{+}_{1}$) value of $^{30}$Mg was determined to be 241(31)$e^{2}$fm$^{4}$. Our result is lower than values obtained at projectile fragmenttion facilities using the intermediate-ene…
The neutron-rich Mg isotopes: first results from MINIBALL at REX-ISOLDE
2004
After the successful commissioning of the Radioactive beam EXperiment (REX) at ISOLDE (CERN) in 2002, first physics experiments were performed in 2003 which focussed on the neutron-rich Mg isotopes in the vicinity of the “island of inversion”. After introducing the REX facility and the modern γ spectrometer MINIBALL first preliminary results will be presented showing the high potential and physics opportunities offered by this new radioactive beam facility.
Position resolution of the prototype AGATA triple-cluster detector from an in-beam experiment
2009
AGATA belongs to a new generation of gamma-ray detector arrays for nuclear spectroscopy at present in its final stage of development. The detectors of these new arrays will be based on 36-fold electronically segmented coaxial germanium diodes operated in position sensitive mode. An in-beam test of the AGATA prototype triple cluster detector was carried out with the purpose of demonstrating the feasibility of such detectors and in order to measure the most sensitive parameters for their overall performance. An inverse kinematics reaction was performed, using a (48)Ti beam at an energy of 100MeV, impinging on a deuterated titanium tat-get. The results from the analysis of the experimental dat…
“Safe” Coulomb Excitation ofMg30
2005
We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient γ spectrometer MINIBALL. Using Mg-30 ions accelerated to an energy of 2.25 MeV/u together with a thin Ni-nat target, Coulomb excitation of the first excited 2(+) states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation γ-ray yields the B(E2;0(gs)(+)R 2(1)(+)) value of Mg-30 was determined to be 241(31)e(2) fm(4). Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the …
Very high rotational frequencies and band termination in73Br
2000
Rotational bands in ${}^{73}\mathrm{Br}$ have been investigated up to spins of $I=65/2$ using the EUROBALL III spectrometer. One of the negative-parity bands displays the highest rotational frequency $\ensuremath{\Elzxh}\ensuremath{\omega}=1.85\mathrm{MeV}$ reported to date in nuclei with $Ag~25.$ At high frequencies, the experimental ${\mathcal{J}}^{(2)}$ dynamic moment of inertia for all bands decreases to very low values, ${\mathcal{J}}^{(2)}l~10{\ensuremath{\Elzxh}}^{2}{\mathrm{MeV}}^{\ensuremath{-}1}.$ The bands are described in the configuration-dependent cranked Nilsson--Strutinsky model. The calculations indicate that one of the negative-parity bands is observed up to its terminatin…
Very high rotational frequencies and band termination in 73Br
2000
Rotational bands in 73Br have been investigated up to spins of 65/2 using the EUROBALL III spectrometer. One of the negative-parity bands displays the highest rotational frequency 1.85 MeV reported to date in nuclei with mass number greater than 25. At high frequencies, the experimental dynamic moment of inertia for all bands decrease to very low values, indicating a loss of collectivity. The bands are described in the configuration-dependent cranked Nilsson-Strutinsky model. The calculations indicate that one of the negative-parity bands is observed up to its terminating single-particle state at spin 63/2. This result establishes the first band termination case in the A = 70 mass region.
Very high rotational frequencies and band termination in 73Br
2000
Rotational bands in 73Br have been investigated up to spins of 65/2 using the EUROBALL III spectrometer. One of the negative-parity bands displays the highest rotational frequency 1.85 MeV reported to date in nuclei with mass number greater than 25. At high frequencies, the experimental dynamic moment of inertia for all bands decrease to very low values, indicating a loss of collectivity. The bands are described in the configuration-dependent cranked Nilsson-Strutinsky model. The calculations indicate that one of the negative-parity bands is observed up to its terminating single-particle state at spin 63/2. This result establishes the first band termination case in the A = 70 mass region.