Measurement of 181 MeV H − ions stripping cross-sections by carbon stripper foil

• DOI: 10.1016/j.nima.2014.12.068
• Publication Date: 2014-12-24T05:15:31Z
• Authors: P.K. Saha; M. Yoshimoto; Y. Yamazaki; H. Hotchi; H. Harada; K. Okabe; M. Kinsho; Y. Irie
• Keywords: 0103 physical sciences; 7. Clean energy; 01 natural sciences

Abstract The stripping cross-sections of 181 MeV H− (negative hydrogen) ions by the carbon stripper foil are measured with good accuracy. The present experiment was carried out at the 3-GeV RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex). The stripping cross-sections for different charge states, also known as electron loss cross-sections of H− ion, are denoted as σ−11, σ−10 and σ01, for both electrons stripping ( H − → H + ), one-electron stripping ( H − → H 0 ) and the 2nd-electron stripping ( H 0 → H + ) proceeding σ−10, respectively. We have established very unique and precise techniques for such measurements so as also to determine a foil stripping efficiency very accurately. The cross-sections σ−11, σ−10 and σ01 are obtained to be ( 0.002 ± 0.001 ) × 10 − 18 cm 2 , ( 1.580 ± 0.034 ) × 10 − 18 cm 2 and ( 0.648 ± 0.014 ) × 10 − 18 cm 2 , respectively. The presently given cross-sections are newly available experimental results for an incident H− energy below 200 MeV and they are also shown to be consistent with recently proposed energy ( 1 / β 2 ) scaled cross-sections calculated from the previously measured data at 200 and 800 MeV. The present results have a great importance not only at J-PARC for the upgraded H− beam energy of 400 MeV but also for many new and upgrading similar accelerators, where H− beam energies in most cases are considered to be lower than 200 MeV.