Pham Dinh Khang

Experimental estimates on radiative strength function of low-energy ?-quanta following even-odd heavy nuclei decay

The applicability of the method of summed amplitudes of coinciding pulses to determine radiative strength functions of heavy nuclei by measuring two-step cascadeγ-ray spectra is discussed. Experiments based on thermal neutron capture in136Ba and180Hf were carried out to test this method. The values obtained for the radiative strength functions of a wide range of primary transitions were compared with the predictions of two modifications of the giant dipole resonance model. Some insight into the characteristics of theγ-decay of compound-states is provided by analyzing the information obtained on the two-stepγ-decay of a number of nuclei in the mass region 137≦A≦187.

Determination of selenium in geological sample by event–event coincidence technique

Selenium plays a role in thyroid function and your immune system which needs selenium to work properly. The quantifying Se in the biological and geological samples are very important to study transferring factor. The advantage of coincidence technique is abilities of background reduction. This technique has been applied for neutron activation analysis (NAA). In this paper, we would like to present the results of selenium determination in geology sample by NAA combined with the technique of event–event coincidence measurement. By application of this technique, the influence isotopes as 182Ta, 181Hf, 152Eu were eliminated.

Determining Experimental Transition Strengths of 52 V by Two-Step Gamma Cascades

In this paper, the results showed experimental transition strengths of 52 V by two-step gamma cascades, lifetime levels, width levels and branch ratio. 51 V nucleus was activated by thermal neutron at the 3 rd horizontal channel of Dalat nuclear reactor, and the 51 V(nth, 2 gamma) 52 V reaction was applied in this research. The two-step gamma cascades were collected by event-event gamma coincidence system. The Summation of Amplitude Coincidence Pulses method (SACP) was treated with the experimental data. The results were not affected by background based on SACP method. This method got intensities, energies of two-step cascades directly. The experimental gamma transition strengths were applied to the single particle model. In comparison with the electromagnetic transition probabilities, and rule of multi orders, the spin and parity of intermediate levels were calculated and refreshed.

On the Construction of a Complex Gamma‐Decay Scheme on the Basis of the Spectroscopic Data from Reactions (n,2γ) and (n,γ)

The extensive and complete level scheme (∼100 levels and 500 transitions) one may determine by the combination of the experimental data from (n,2γ) and (n,γ) reaction.