Observation and analysis for motions of trapped microparticles in the TRISTAN accumulation ring

Signals of high-energy bremsstrahlung in the TRISTAN accumulation ring was observed with lead-glass counters, accompanied by a sudden decrease in the electron beam lifetime which occurred due to microparticle trapping in the electron beam. The observation showed a trapped microparticle made a periodic oscillation; the period was 1 s. The observation coincides with the result based on our newly developed theory for vertical oscillation of a trapped microparticle. Furthermore, the calculated variation in the beam lifetime also coincides with the actual variation in the beam lifetime