Automatic Control and Precise Filling of Alkali-Metal Gas into Glass Vesicles:A Methodological Study

The non-standard equipment,dedicated to the automatically and precisely filling of alkaline metal gas into glass vesicles,was developed.Based on Maxwell distribution law of gas velocity and Langmuir evaporation/condensation theory,the self-developed equipment comprises the vacuum chamber,pumping unit,PLC controller,3 D-workpiece positioner,heater/cooler/thermostat,suppliers of ultrapure gases and etc.The lab-built equipment was tested in fabrication of rubidium vesicles.The results show that the automatic filling significantly outperforms the conventional manual filling.For instance,the proportion of vesicles filled with Rb-content of 500±100 μg increased from 35% to 73%;and the dispersion decreased from ±550 μg to ±150 μg.We suggest that the self-developed equipment be of some technological interest because of batch fabrication,high automation,easy operation and long-term reliability.