Provided is a method for filling a stem-side hollow area of an engine valve with metallic sodium. The method includes injecting melted metallic sodium into a cylinder having a larger diameter than an inner diameter of the hollow area of the engine valve, forming a solidified metallic sodium rod having a substantially uniform structure in the cylinder, inserting the metallic sodium into the hollow area of the engine valve through a nozzle having a small diameter, and sealing the engine valve.

The invention relates to a method for obtaining caesium from aqueous starting solutions having caesium contents in the range of 50 ppm to 5000 ppm, in which method the caesium ions in the aqueous solution are, in a first step, precipitated as a double salt having divalent cations with the aid of an at least 1.1-times overstoichiometric amount of solutions containing prussiate of potash, in a pH range of 2 to 12 and a temperature range of 10 to 80 C., the divalent cations either already being present in the starting solutions in an amount at least equimolar to the caesium content or being added as a water-soluble salt, and, in a second step, converted back into a water-soluble form by thermal decomposition and, in a third step, separated from the insoluble residues.

The invention relates to a method for obtaining caesium from aqueous starting solutions having caesium contents in the range of 50 ppm to 5000 ppm, in which method the caesium ions in the aqueous solution are, in a first step, precipitated as a double salt having divalent cations with the aid of an at least 1.1-times overstoichiometric amount of solutions containing prussiate of potash, in a pH range of 2 to 12 and a temperature range of 10 to 80 C., the divalent cations either already being present in the starting solutions in an amount at least equimolar to the caesium content or being added as a water-soluble salt, and, in a second step, converted back into a water-soluble form by thermal decomposition and, in a third step, separated from the insoluble residues.

This invention relates to treated geothermal brine compositions containing reduced concentrations of iron, silica, and manganese compared to the untreated brines. Exemplary compositions contain a concentration of manganese less than 10 mg/kg, a concentration of silica ranging from less than 10 mg/kg, and a concentration of iron less than 10 mg/kg, and the treated geothermal brine is derived from a Salton Sea geothermal reservoir.

This invention relates to treated geothermal brine compositions containing reduced concentrations of iron, silica, and manganese compared to the untreated brines. Exemplary compositions contain a concentration of manganese less than 10 mg/kg, a concentration of silica ranging from less than 10 mg/kg, and a concentration of iron less than 10 mg/kg, and the treated geothermal brine is derived from a Salton Sea geothermal reservoir.

An alkali-metal dispenser to dispense highly pure rubidium in a high-vacuum environment while not negatively impacting the high-vacuum pressure level. The alkali-metal dispenser is operable in various vapor-deposition applications or to provide a highly pure elemental-alkali metal in cold-atom magneto-optical traps.

A method for generating alkali metal in a zero oxidation state includes reacting an alkali metal compound having a S-M substituent, where M is an alkali metal and S is sulfur, with gold in a zero oxidation state to release the alkali metal in the zero oxidation state. For example, an alkali metal alkylthiolate can be reacted with a gold in a zero oxidation state to release the alkali metal in the zero oxidation state. As another example, an alkali metal sulfide can be reacted with gold in a zero oxidation state to release the alkali metal in the zero oxidation state. The alkali metal may be used in various applications including vapor cells, magnetometers, and magnetic field measurement systems.

A method for generating alkali metal in a zero oxidation state includes reacting an alkali metal compound having a S-M substituent, where M is an alkali metal and S is sulfur, with gold in a zero oxidation state to release the alkali metal in the zero oxidation state. For example, an alkali metal alkylthiolate can be reacted with a gold in a zero oxidation state to release the alkali metal in the zero oxidation state. As another example, an alkali metal sulfide can be reacted with gold in a zero oxidation state to release the alkali metal in the zero oxidation state. The alkali metal may be used in various applications including vapor cells, magnetometers, and magnetic field measurement systems.

Some variations provide an alkali metal or alkaline earth metal vapor cell with a solid ionic conductor and intercalable-compound electrodes. The intercalable-compound electrodes are used as efficient sources and/or as sinks for alkali metal or alkaline earth metal atoms, thus enabling electrical control over metal atom content in the vapor cell. Some variations provide a vapor-cell system comprising: a vapor-cell region configured to allow a vapor-cell optical path into a vapor-cell vapor phase; a first electrode containing an intercalable compound capable of being intercalated by at least one element selected from Rb, Cs, Na, K, or Sr; a second electrode electrically isolated from the first electrode; and an ion-conducting layer between the first electrode and the second electrode. The ion-conducting layer is ionically conductive for at least one ionic species selected from Rb.sup.+, Cs.sup.+, Na.sup.+, K.sup.+, or Sr.sup.2+. The first intercalable compound is preferably a carbonaceous material, such as graphite.

Some variations provide an alkali metal or alkaline earth metal vapor cell with a solid ionic conductor and intercalable-compound electrodes. The intercalable-compound electrodes are used as efficient sources and/or as sinks for alkali metal or alkaline earth metal atoms, thus enabling electrical control over metal atom content in the vapor cell. Some variations provide a vapor-cell system comprising: a vapor-cell region configured to allow a vapor-cell optical path into a vapor-cell vapor phase; a first electrode containing an intercalable compound capable of being intercalated by at least one element selected from Rb, Cs, Na, K, or Sr; a second electrode electrically isolated from the first electrode; and an ion-conducting layer between the first electrode and the second electrode. The ion-conducting layer is ionically conductive for at least one ionic species selected from Rb.sup.+, Cs.sup.+, Na.sup.+, K.sup.+, or Sr.sup.2+. The first intercalable compound is preferably a carbonaceous material, such as graphite.