Standardization and nuclear decay data of 65Zn

Standardization of 65Zn by sum-peak method

A commercial solution of (65)Zn was standardized by the sum peak-method using a planar HPGe detector. The activity results were compared with measurements made with a well type 4πγ ionization chamber, which is traceable to BIPM.RI (II)-K2.Zn-65 key-comparison performed in 2002. The sum-peak value was 42.79 kBq/g and the ionization chamber value was 42.74 kBq/g both at the reference date. The uncertainty obtained in the sum peak standardization was 0.25% (k=1), and in the ionization chamber was 0.85% (k=1). The results showed that sum-peak method can be used in (65)Zn standardization and this method is easier, simpler and more practical than others methods.

Nuclear decay data: Observations and reflections

Decay data constitute an important feature of nuclear physics that plays a significant role in the various work programmes of members and associates of the International Committee for Radionuclide Metrology (ICRM). At the invitation of the ICRM, a review has been undertaken with the joint aims of emphasising decay-data achievements over the previous 10 years, and highlighting inadequacies that remain to be addressed in the future.

The LSC efficiency for low-Z electron-capture nuclides

In this paper, we apply the CIEMAT/NIST method to the three low-Z electron-capture nuclides 54Mn, 55Fe and 65Zn by using the KLM and KL1L2L3M atomic rearrangement models, respectively. The counting efficiencies are computed with the new code EMILIA, which comprises an improved model for the interaction of low-energy X-rays with the scintillation cocktail. The calculated counting efficiencies are compared with experimental results.

A new method for secondary standard measurements with the aid of liquid scintillation counting

A new secondary standard measuring procedure based on liquid scintillation counting has been developed at PTB. In this procedure, the efficiency curve, i.e. the counting efficiency of the nuclide to be investigated as a function of the tritium counting efficiency, is-in contrast to the CIEMAT/NIST method-not calculated but determined by experiment. For the measurements, gamma-emitting activity standards are used which were calibrated by other methods. The procedure was successfully used to calibrate solutions of the radionuclides 54Mn, 57Co, 65Zn, 85Sr and 125I with small uncertainties.