Preparation of the 178m2Hf isomer used in the induced gamma decay experiment by X-ray from synchrotron radiation facility

It is widely acknowledged that the ^178m2Hf nuclide is the most suitable substance to study the decay characteristic of the isomer induced by low-energy X-ray. In order to conduct the experiment on the induced gamma emission, the research group has started producing the ^178m2Hf nuclide based on the ¹⁷⁶Yb(??, 2n)^178m2Hf reaction. After the chemical purification is conducted, the sample is prepared and used in Shanghai Synchrotron Radiation Facility. During the production of isomer, the natural metal Yb target is got through magnetron sputtering. Bombarded by ?? particles about 27 MeV, the ^178m2Hf nuclide reaches about 10¹². Yb target prepared in this way is most suitable for the production of ^178m2Hf nuclide in the CS30 cyclotron. There are various nuclides in the irradiated target and the main long-lived nuclides are ¹⁷³Lu, ¹⁷²Lu, ¹⁷⁵Hf, ¹⁷²Hf and ⁶⁵Zn. The chemical separation of ^178m2Hf is studied and its process is monitored by radioactive tracer. The above result shows that decontamination factors of Zn and Lu are 10⁵ and 10³, respectively, and the yield of hafnium is 69%. Under the protection of vacuum filtration technology, the purified ^178m2Hf isomers are entirely transferred to the surface of filter paper, in order to form the sample which satisfies requirements of X-ray triggering the ^178m2Hf isomer decay experiment in Shanghai Synchrotron Radiation Facility in the future.