The Study On Measurement System Of Loss Beam On Electron Storage Ring

HLS is the second-generation special synchrotron radiation light source which based on vacuum ultraviolet and soft X-ray. HLS is low-energy light source, and the designed energy of the electron storage ring is 800MeV. Beam energy is a very important parameter in electron storage ring, so it is should to be measured accurately. We prepare to adopt the spin resonance depolarization method to measure energy in Hefei electron storage ring. This article is based on this topic. It introduced the basic principle and experimental methods of the spin resonance depolarization, theoretical simulationed the interaction between the electron and vacuum chamber in storage ring, developed a set of beam loss detection system to be used in experiment, and prepared for the accurate measurement of energy in future.In electron storage ring, synchrotron radiation effects would make the orientation of electron spin toward consistent and eventually leading to the spontaneous polarization of the beam to be established. The polarized beam can also be depolarization on an external field of certain frequency. After depolarization, beam life will become shorter, so the beam loss will also become larger. The frequency of the external field that caused beam depolarization has a certern function relationship with the beam energy, so we can use this principle to measure the energy of storage ring indirectly: we can determine the resonance depolarization point by observing the changes in beam loss. When the frequency of this point has been measured, we can calculate the exact value of the energy according to the formula. Thus, establishing a precise beam loss measurement system is essential for the success of the experiment.Therefore, we first introduced the concept of spin-polarized and beam life in this paper. Then, we get the distribution of secondary particleson outside vacuum by the EGSnrc, according to the experimental needs of spin resonance depolarization method. And, we established a set of beam loss measurement system which consists of plastic scintillator detectors, photomultiplier tubes and digital signal processing circuit. Experimental result shows that, this system can sensitively measure and reflect the changes of beam loss, so it can be used in spin resonance depolarization experiment.Hefei National Synchrotron Radiation Laboratory is the first lab in China to try to use spin resonance depolarization method to measure beam energy, so it has some innovative and research significance. In addition, this thesis also has some reference value in the work of beam lifetime study, radiation protection, source fault detection.