An ion pump controller configured to alternate between increasing and decreasing a potential difference between an anode and a cathode of an ion pump multiple times during the starting of pumping.

An ion pump controller configured to alternate between increasing and decreasing a potential difference between an anode and a cathode of an ion pump multiple times during the starting of pumping.

A high PAR maintenance rate type high pressure sodium lamp with an auxiliary starting switch is provided with an external glass tube and a discharge tube which is arranged at the center in the external glass tube and coaxial with the external glass tube. The surface of the discharge tube is provided with a metal lead. The left and right ends of an external glass shell are provided with pressure sealing plates which are fused and sealed through high temperature. The pressure sealing plates are internally provided with conductive sheets. One end of the discharge tube is connected with the conductive sheet of the left end through a left internal conductive support, and the other end is connected with the conductive sheet of the right end through an auxiliary starting switch component. According to the high pressure sodium lamp, the high pressure sodium lamp can be quickly lit up through a temperature controlled switch so that the high pressure sodium lamp has the advantages of being great in starting performance, great in lighting effect, high in stability, long in the service life, great in high temperature resistance and high pressure resistance and safe and reliable and is not liable to crack.

There is provided a pipe in a solar thermal power plant. The pipe includes an inner tube configured for carrying a heated heat transfer fluid, an outer tube surrounding the inner tube, wherein the space between the inner and outer tube is evacuated, and a getter restraint structure configured for maintaining getters in a predetermined position. The getter restraint structure is in contact with the outer tube and otherwise entirely free of contact with the inner tube and/or is in thermal isolation from the inner tube.

There is provided a vacuum switching assembly for switching an AC or DC current. The vacuum switching assembly comprises a vacuum switch. The vacuum switch includes: first and second electrodes (20, 22) located in a vacuum tight enclosure, the vacuum tight enclosure containing a gas or gas mixture, the first and second electrodes (20, 22) defining opposed electrodes being separated by a gap, each of the first and second electrodes (20,22) being connectable to a respective electrical circuit carrying an AC or DC voltage; and a pressure controller (36) configured to control an internal pressure of the vacuum tight enclosure, wherein the pressure controller (36) is configured to selectively switch the internal pressure of the vacuum tight enclosure between: a first vacuum level that permits formation and maintenance of a glow discharge in the vacuum tight enclosure to allow a current to flow between the first and second electrodes (20, 22) via the glow discharge so as to turn on the vacuum switch; and a second vacuum level that inhibits formation and maintenance of a glow discharge in the vacuum tight enclosure to prevent a current from flowing between the first and second electrodes (20, 22) via the glow discharge so as to turn off the vacuum switch.

There is provided a vacuum switching assembly for switching an AC or DC current. The vacuum switching assembly comprises a vacuum switch. The vacuum switch includes: first and second electrodes (20, 22) located in a vacuum tight enclosure, the vacuum tight enclosure containing a gas or gas mixture, the first and second electrodes (20, 22) defining opposed electrodes being separated by a gap, each of the first and second electrodes (20,22) being connectable to a respective electrical circuit carrying an AC or DC voltage; and a pressure controller (36) configured to control an internal pressure of the vacuum tight enclosure, wherein the pressure controller (36) is configured to selectively switch the internal pressure of the vacuum tight enclosure between: a first vacuum level that permits formation and maintenance of a glow discharge in the vacuum tight enclosure to allow a current to flow between the first and second electrodes (20, 22) via the glow discharge so as to turn on the vacuum switch; and a second vacuum level that inhibits formation and maintenance of a glow discharge in the vacuum tight enclosure to prevent a current from flowing between the first and second electrodes (20, 22) via the glow discharge so as to turn off the vacuum switch.