New Method for Measuring Pulsed Muon Beam Intensity Using Silver Activation
Researchers have identified silver-107 as a promising isotope for measuring the absolute intensity of pulsed muon beams at accelerator facilities, addressing a long-standing experimental challenge. The method relies on detecting beta-delayed gamma rays produced when muons are captured by nuclei, with measurements of production branching ratios for copper, zinc, and silver isotopes. This advancement enables more precise beam intensity measurements over short periods, which is critical for experiments requiring accurate muon beam characterization.
Scientists have developed and validated an in-beam activation method to determine the absolute number of negative muons in pulsed beams, a measurement that has been difficult at high intensities. The technique measures beta-delayed gamma rays emitted from residual nuclei after muon nuclear capture reactions. The research measured production branching ratios for muon capture on natural abundance copper, zinc, and silver isotopes to identify suitable candidates for calibration. Among these, the reaction of muons with natural silver producing metastable palladium-107 was found to be the most practical reference for muon number calibration, considering factors such as branching ratio strength, muon capture probability, detector efficiency, and material availability. This development expands the limited set of isotopes with reliable branching ratio measurements needed for absolute muon beam intensity determination.
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- arXiv physicsCenter
Absolute intensity measurement of pulsed muon beams using in-beam activation
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