Investigation of beam loss mechanism by parasitic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi mathvariant="normal">H</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> in high-power proton linac

Beam loss is the most critical topic in the high-power accelerator community. During high-power proton beam commissioning of Chinese ADS Front end, unexpected irradiation dose was detected opposite to the proton beam deflection direction. This indicates that there are parasitic <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi mathvariant="normal">H</a:mi><a:mo>−</a:mo></a:msup></a:math> particles inside the proton beam, which were first observed in the linac facility. In the paper, regarding this beam loss phenomenon, a qualitative analysis was carried out through nuclide analysis and was based on the theoretical foundation of molecular science. Moreover, a quantitative analysis was conducted through beam experiments, and finally verified this beam loss mechanism, which needs to be considered in the future design of high-intensity and high-power proton accelerators.