Study of 26Al measurement on the Shanghai Mini-cyclotron based AMS

We present a modification to the 14C-dedicated SMCAMS (Shanghai mini-cyclotron based AMS) system to allow the measurement of 26Al for biomedical applications with the existing devices. This is accomplished by determining the turn number, harmonic number and RF frequency theoretically and then making the appropriate orbit programming and beam optics calculation and experimental adjustments. The tests were conducted using pencil graphite (for the carbon pilot beam), Al2O3 powder and metal aluminum to accelerate ions with mass number of 24, 25, 26 and 27. The frequency response curves for those ions are shown. Finally, the Al2O3 standard sample with a known isotope ratio of 1.0 × 10−10 is measured. The 26Al− ions are detected and its frequency response curve shows the peak of 26Al− though very weak is well separated from the most neighboring interfering molecular ions 25MgH−.