Abstract
雷射與高能電子束行康卜吞散射所產生的散射光子可提供電子束的能量資 訊。 電子束能量的決定取決於康卜吞散射之散射光子的訊雜比 (Signal to Noise Ratio; S/N)。本研究利用同步測量的方法以增加訊雜比。此方 法中，二氧化碳雷射提供同步測量的觸發訊號；此觸發訊號經由適當的延 遲以獲得最佳的訊雜比。本實驗以二氧化碳雷射(0.1172eV)與同步輻射中 心儲存環中的電子束(1.3GeV, 19mA)對撞，所產生的散射光子之最高能量 約為3.021MeV，訊雜比約為42.5。雷射與高能電子束行康卜吞散射所產生 的散射光子可提供電子束的能量資訊。電子束能量的決定取決於康卜吞散 射之散射光子的訊雜比(Signal to Noise Ratio; S/N)。本研究利用同步 測量的方法以增加訊雜比。此方法中，二氧化碳雷射提供同步測量的觸發 訊號；此觸發訊號經由適當的延遲以獲得最佳的訊雜比。本實驗以二氧化 碳雷射(0.1172eV)與同步輻射中心儲存環中的電子束(1.3GeV, 19mA)對撞 ，所產生的散射光子之最高能量約為3.021MeV，訊雜比約為42.5。本實驗 以二氧化碳雷射(0.1172eV)與同步輻射中心儲存環中的電子束 (1.3GeV, 19mA) 對撞，所產生的散射光子之最高能量約為3.021MeV，訊雜比約為 42.5。 Laser Compton scattering by relativistic electrons provides the energy information associated with electron beams in an accelerator. Determining the electron beam energy by this method depends primarily on the signal to noise (S/N) ratio associated with laser Compton scattering. In this study, we propose a method to enhance the S/N ratio by synchronous measurement with a high peak power pulsed CO2 laser. In this method, the pulsed CO2 laser provides the gate trigger signals, and the delay times of the triggers are optimized to obtain a maximum S/N ratio. In the storage ring of Taiwan Light Source, a g-ray with the highest energy of 3.021MeV was back-scattered after the 0.1172eV CO2 laser photons colliding with the relativistic electrons. The S/N ratio is about 42.5 with the electron beam current being 19mA. Also, the measured electron beam energy is 1.3058GeV with relative uncertainty 0.13%.