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 vacuum tube includes a filament and two pairs of a grid and an anode. The filament is tensioned linearly and emits thermoelectrons. Both of the anodes are formed on a same face on a planar substrate. The filament is arranged parallel to the planar substrate at a position facing both of the anodes. Each of the grids is arranged, such that the grid faces the anode of a same pair at a first predetermined distance from the anode and has a second predetermined distance from the filament, between the anode and the filament. The vacuum tube further includes an intermediate filament fixing part fixing the filament at a position corresponding to an intermediate point between the anodes of the two pairs.

The vacuum tube subject to the present invention comprises a filament and two pairs of a grid and an anode. The filament is tensioned linearly and emitting thermoelectrons. Both of the anodes are formed on the same face on a planar substrate. The filament is arranged parallel to the planar substrate at a position facing both of the anodes. Each of the grids is arranged, such that the grid faces the anode in the same pair at a first predetermined distance from the anode and has a second predetermined distance from the filament, between the anode and the filament. The vacuum tube comprises an intermediate filament fixing part fixing the filament at a position corresponding to an intermediate point between the anodes of the two pairs.

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.