The intermediate-energy heavy ion microbeam facility at the Institute of Modern Physics, Chinese Academy of Sciences (IMP) has passed the site test organized by the Bureau of Planning & Finance of Chinese Academy of Sciences(CAS) in July 2011.

12C6+ beam with the energy of 80.55 MeV/u was used in the test, which was supplied by the cascade of cyclotrons of the Heavy Ion Research Facility in Lanzhou (HIRFL). The inverted fluorescent microscope was employed to observe and measure the full width at half maximum (FWHM) of the beam spot in air.  Fig.1 shows the test result with 1.7±0.2µm in X direction and 1.5±0.2µm in Y direction. The irradiated and etched CR-39 track detector was also used to verify the beam spot size and the positioning accuracy. Fig.2 shows the corresponding FWHM with 1.8±0.3µm in X direction and 1.0±0.2µm in Y direction. The ion frequency can be adjusted between 1 particle to 1200 particles per second. The test results shows that the intermediate-energy heavy ion microbeam facility has achieved the quality inspection specifications.

The intermediate-energy heavy ion microbeam facility in HIRFL is the heavy ion microbeam facility with the highest energy in the world, which has many advantages, such as wide energy range, many ion species, vertical irradiation etc. It is a focused microbeam facility and is suitable to irradiate either materials in vacuum or biological living cells in air.

This facility is developed independently by IMP and supported by the CAS Scientific Research Equipment Development Program. Its successful construction shows China’s ability to develop high-precision equipments.

Fig.1 The beam spot (scintillation light) observed by the online inverted fluorescent microscope(Image by IMP)

Fig.2 The beam spot size in the irradiated and etched CR-39(Image by IMP)