A device used in pulsed slow positron beam's stretching

作者：Wei Cun Feng^*; Wang Bao Yi; Wang Ping; Cao Xing Zhong; Zhang Zhi Ming; Ma Yan Yun; Xue De Sheng; Wei Long

来源：Chinese Physics C, 2006, 30(10): 1010-1013.

• Penning-Trap
• stretching
• slow positron beam
• positron annihilation

A slow positron beam's stretching device has been designed and constructed on Beijing Slow Positron Beam, which based on a 1.3GeV linac. Positron was storage and stretching use Penning-Trap technique. Measurements show that the positron storage time strongly depends on the vacuum level in Penning Trap tube. Two modes was used to release the positrons from storage part, lowering V-C while V-B kept constant and rising Vs while V-C kept constant. This technique makes the pulsed positron beam to a quasi-continuous beam. The energy spread of positrons depend on in release mode. In the latter mode, we observe that the energy spread was reduced to a value less than 1.0eV. The time profile in user-defined waveform is more uniform. It is beneficial to reduce the probability of amplifier pileup especially in the case of measurement with high counting rate.

• 出版日期2006-10
• 单位兰州大学