Zy Guo

RIBLL, the radioactive ion beam line in Lanzhou

A fragment separator, the Radioactive Ion Beam Line in Lanzhou, has been constructed at the Heavy Ion Research Facility of Lanzhou and in operation since January 1998. In this paper, the features of the structure and performance are described in detail. Some early stage results are presented also.

Measurement of reaction cross section for proton-rich nuclei ( A< 30) at intermediate energies

Radioactive ion beams were produced through the projectile fragmentation induced by 69 MeV/nucleon Ar-36 primary beam on a Be-9\ target. Measurements of reaction cross sections (sigma(R)s) for 44 nuclei with A < 30 (mostly proton-rich), on carbon were performed on RIBLL (Radioactive Ion Beam Line in Lanzhou) of HIRFL (Heavy Ion Research Facility in Lanzhou) at intermediate energies around 30 MeV/nucleon by a transmission method. The experimental sigma(R) values for Al-23 and P-27 are abnormally large compared with their neighboring nuclei. Together with the previous experimental facts such as the binding energy and ground state data, it suggests anomalously large matter root-mean-square radii and proton halo structure in Al-23 and in P-27. There is an enhancement for the sigma(R) of F-17 + C-12 compared with the neighboring isotopes. Considering that the ground state of F-17 is 1d(5/2), this can indicate that there is a proton skin in F-17. The calculation of relativistic density-dependent Hartree model (RDDH) shows that the nuclei Al-23 and P-27 may have proton-halo structure and F-17 may have proton-skin structure. The significance of these measurements is discussed

Obvious enhancement of the total reaction cross sections for

The reaction cross sections of

^{27,28}

^{27,28}

P with

P and the corresponding isotones on Si target were measured at intermediate energies. The measured reaction cross sections of the N=12 and 13 isotones show an abrupt increase at

^{28}

% Z=15

Si target and the possible relavent mechanisms

. The experimental results for the isotones with

Radioactive ion beam line in Lanzhou

Z\leq 14

RMF calculation and phenomenological formulas for the rms radii of light nuclei

as well as

Two‐proton Halo and Two‐proton Emission Nucleus: 29S

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