"Measurement of interaction cross sections for neutron rich Na Isotopes"
Takamasa Kuboki, Department of Physics, Saitama University, JAPAN
(id #74)
Seminar: YesPoster: No
Invited talk: No
Measurements of interaction cross sections (σI) at relativistic energies allow us to determine nuclear matter radii for unstable nuclei via Glauber model analysis.
Since nuclear matter radii are directly related to the nuclear matter density distribution, the measurement of σI is a good tool to search for unusual nuclear structures, such as skins and halos.
Nuclear matter radii and neutron skin thicknesses of Na isotopes have been determined by T. Suzuki et al. via measurements of σI in the mass range from A = 20 to 32 at GSI.
They found the existence of neutron skin in the neutron rich Na isotopes for the first time.
Recently, intensive efforts have been devoted to nuclei around the 'island of inversion', in both experimentally and theoretically, where the neutron fp shell is known to contributes significantly to the ground-state structure.
However, beyond A = 32 of Na isotopes, no measurement of σI has been done because of their very low production rate.
Now the combination of high intensity 48Ca beam and the next generation fragment separator (BigRIPS) at the RIKEN RIBF facility has opened to access such drip-line nuclei.
In order to investigate the nuclear structure around island of inversion, we measured σI of neutron rich sodium isotopes 29-35Na at 250MeV/nucleon by a transmission method using BigRIPS and determined the nuclear matter radii of those nuclei.
Experimental setup is essentially the same as our previous experiment at GSI.
A primary beam of 345MeV/nucleon 48Ca with a typical intensity of 100 pnA was bombarded a Be production target.
The produced fragments were pre-separated at the 1st stage of BigRIPS.
The carbon reaction target with 3.6g/cm2 thickness was placed at the middle focus point of the 2nd stage of BigRIPS.
The first and second half's of the 2nd stage of BigRIPS were used to separate and identify the incident and outgoing secondary beam with a Bρ ΔE TOF method, respectively.
In the case of 30-32Na, we accumulated more than 10^5 events, which corresponds to the accuracy in around 1 %.
The experimental results and discussion on their nuclear structure will be presented.
Since nuclear matter radii are directly related to the nuclear matter density distribution, the measurement of σI is a good tool to search for unusual nuclear structures, such as skins and halos.
Nuclear matter radii and neutron skin thicknesses of Na isotopes have been determined by T. Suzuki et al. via measurements of σI in the mass range from A = 20 to 32 at GSI.
They found the existence of neutron skin in the neutron rich Na isotopes for the first time.
Recently, intensive efforts have been devoted to nuclei around the 'island of inversion', in both experimentally and theoretically, where the neutron fp shell is known to contributes significantly to the ground-state structure.
However, beyond A = 32 of Na isotopes, no measurement of σI has been done because of their very low production rate.
Now the combination of high intensity 48Ca beam and the next generation fragment separator (BigRIPS) at the RIKEN RIBF facility has opened to access such drip-line nuclei.
In order to investigate the nuclear structure around island of inversion, we measured σI of neutron rich sodium isotopes 29-35Na at 250MeV/nucleon by a transmission method using BigRIPS and determined the nuclear matter radii of those nuclei.
Experimental setup is essentially the same as our previous experiment at GSI.
A primary beam of 345MeV/nucleon 48Ca with a typical intensity of 100 pnA was bombarded a Be production target.
The produced fragments were pre-separated at the 1st stage of BigRIPS.
The carbon reaction target with 3.6g/cm2 thickness was placed at the middle focus point of the 2nd stage of BigRIPS.
The first and second half's of the 2nd stage of BigRIPS were used to separate and identify the incident and outgoing secondary beam with a Bρ ΔE TOF method, respectively.
In the case of 30-32Na, we accumulated more than 10^5 events, which corresponds to the accuracy in around 1 %.
The experimental results and discussion on their nuclear structure will be presented.
