Study on the Low-Ignition Voltage Helium Neon Laser(II) --Mechanism of Lowering Ignition Voltage

摘要

For the purpose of studying the mechanism of lowering ignition voltage in the Gao-type He-Ne laser, three kinds of laser tubes (the traditional type, the Gao-type I and Gao-type II, see Fig.l.) have been made and ignition voltage measurements were performed in several gases (He, Ne, He-Ne, Ar, Kr, H_2 and N_2). The experimental results showed that the ignition voltages for Gao-types are fairly lower than that of the tradition! one, but this effect persists only within a certain range of gas pressure. As the gas pressure increases to a certain value P_o, which depends on the gas kind, the lowering effects vanish. Figure 1 shows schematically the three kinds of laser tubes, while Figure 2 shows the dependences of breakdown voltages on gas pressures. It is seen that the lowering effect tends to zero as gas pressure increases. A theoretical explanation for the experimental results is also given.