Ⅰ.引言早期的質譜計仅用作探测同位素的存在、多寡和决定它們的質量数,而近年来質譜在工业生产和研究的领域里取得了新的前途。在电真空工业中,近年来很重要的一个課題是如何延長电子管的寿命。例如在电子計算机中使用着越来越多的电子管,这些电子管將統計地輪流損坏,因此如果使用長寿命的电子管,將使电子計算机的可靠性大为提高;同样,海底通訊用的电子管也不可能經常更換,因此也要求長寿命的 I. INTRODUCTION Early mass spectrometers were only used to detect the presence, amount, and mass of isotopes, and mass spectrometry has gained new promise in industrial production and research in recent years. In the electric vacuum industry, a very important issue in recent years is how to extend the life of the electron tube. For example, more and more electronic tubes are used in electronic computers, and the electronic tubes will be statistically broken in turns. Therefore, the reliability of the electronic computer will be greatly improved if long-life electronic tubes are used. Similarly, It is impossible to change frequently, so long life is also required