First Image of Muon Particle

Chinmoy Kumar

B.Sc 1^st Sem(Physics Major)

A new technique has taken place to capture the first image of muon particle beams. From Nagoya University scientists had designed the imaging techniques with colleagues in Osaka University and KEK, Japan and described in its journal Scientific Reports on 26^th November, 2020. They planned to assess the quality of these beams, which are being used more and more in advanced imaging applications.

Muons are charged particles which are which are 207 times the mass of electrons. Muons form naturally when cosmic rays strike atoms in the upper atmosphere, showering down onto every part of Earth’s surface. They could penetrate through hundreds of meters of solids before being absorbed.

Nagoya University Biomedical nuclear scientist Seiichi Yamamoto and colleagues a new technique for imaging the muon beams. And it might benefitted in future for further research of muons.

The technique depends on a phenomenon that when charged particles travel through a transparent media, like water. Water slows light down relative to high-energy particles. Particles which moves faster than light cause something similar to the sonic boom we hear when a jet plane breaks the sound barrier. In case of particles it is known as ‘optical boom’ and this effect is known as Cherenkov effect and it causes brief flash. Yamamoto and his colleagues used positive muons with momenta of 73.9 MeV/c, 84.5 MeV/c and 95.1 MeV/c. They used positive muons for imaging the experiment because the intensities of the positive muons at Japan Proton Accelerator Research Complex(J-PARC) were higher than that of negative muons and radionuclide production by irradiation which is negligible for positive muons. They imaged that effect with a special camera when a muon beam was directed through water or a plastic scintillator block. This technique allowed them to image muons and positrons also that formed when muons decay. This technique also helped them to measure the beam’s range through water or plastic scintillator, and to measure the deviation the deviation of its momentum that it is found to be 4%. As well as this technique clarify the direction of position movement . Yamamoto says that the system they used are compact, low cost and easy to use. And this system proves that it is a promise tool for quality assessment in muon beam facilities and it will be helpful in future for further studies of muon.