A tungsten electrode material contains a tungsten-based material and oxide particles dispersed in the tungsten-based material. The oxide particles are composed of an oxide solid solution in which a Zr oxide and/or an Hf oxide and an oxide of at least one rare earth selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu are dissolved as a solid solution. A content of the rare-earth oxide with respect to a total amount of the Zr oxide and/or the Hf oxide and the rare-earth oxide is not lower than 66 mol % and not higher than 97 mol %, a content of the oxide solid solution is not lower than 0.5 mass % and not higher than 9 mass %, and the remainder is composed substantially of tungsten.

An electrode module includes an electrode and a core wire inserted into a core wire insertion hole of the electrode. When inserting the core wire into the core wire insertion hole of the electrode, the core wire can be inserted smoothly, thereby avoiding occurrence of chipping or cracking in the core wire insertion hole. A low-friction layer is provided on the inner surface of the core wire insertion hole of the electrode and/or the outer periphery of the inserted portion of the core wire.

An electrode module includes an electrode and a core wire inserted into a core wire insertion hole of the electrode. When inserting the core wire into the core wire insertion hole of the electrode, the core wire can be inserted smoothly, thereby avoiding occurrence of chipping or cracking in the core wire insertion hole. A low-friction layer is provided on the inner surface of the core wire insertion hole of the electrode and/or the outer periphery of the inserted portion of the core wire.

It is an object to provide a tungsten alloy exhibiting characteristics equal to or higher in characteristics than those of a thorium-containing tungsten alloy, without using thorium which is a radioactive material, and a discharge lamp, a transmitting tube, and a magnetron using the tungsten alloy. According to the present invention, a tungsten alloy includes 0.1 to 5 wt % of Zr in terms of ZrC.

A high-frequency electrode for a medical device includes an electrode base material and an oxide. The electrode base material is made of a metal or an alloy. The oxide is added into the electrode base material. The metal or alloy has a melting point of 2000 C. or higher. The oxide has a particle diameter of 2 m or more.

According to one embodiment, a tungsten alloy includes 0.1 to 5 wt % of Zr in terms of ZrC.

Sulfur arc lamp includes an arc chamber that has a cathode and an anode both made of refractory metals that include pure tungsten, pure molybdenum, tungsten alloy, molybdenum alloy or a composite in which tungsten is at least 90%, or a composite in which molybdenum is at least 90%; a plasma initiation gas filling the plasma chamber; power supply configured to switch on and off electric arc discharge between the cathode and anode; second chamber connected to the arc chamber for releasing sulfur vapor into the plasma arc chamber, thereby creating a sulfur-containing plasma gas when the discharge occurs, and configured to selectively remove the sulfur vapor from the sulfur-containing plasma gas when the discharge occurs, wherein the second chamber is configured to reduce a concentration of the sulfur vapor in the arc chamber below 10.sup.13 molecules per cm.sup.3 before the electric arc discharge is off.

A sulfur plasma lamp has a lamp envelope of transparent or translucent glass or ceramic material. At least two silicon carbide electrodes are hermetically sealed with the lamp envelope and in contact with an interior of the lamp envelope. A quantity of sulfur within the interior of the lamp envelope is sufficient to create a sulfur plasma upon excitation. A buffer gas within the interior of the lamp envelope enables initial discharge and heating of the interior of the lamp envelope to excite the sulfur into a plasma state. More than two electrodes may be provided, and an electrical potential is created between different pairs of the electrodes at different times, thereby inducing stirring of the plasma upon excitation of the material into a plasma state.

A sulfur plasma lamp has a lamp envelope of transparent or translucent glass or ceramic material. At least two silicon carbide electrodes are hermetically sealed with the lamp envelope and in contact with an interior of the lamp envelope. A quantity of sulfur within the interior of the lamp envelope is sufficient to create a sulfur plasma upon excitation. A buffer gas within the interior of the lamp envelope enables initial discharge and heating of the interior of the lamp envelope to excite the sulfur into a plasma state. More than two electrodes may be provided, and an electrical potential is created between different pairs of the electrodes at different times, thereby inducing stirring of the plasma upon excitation of the material into a plasma state.

A discharge lamp includes a luminous tube and a pair of electrodes. At least one of the pair of electrodes includes a core material, a coil section in which a metal wire is wound on the core material in three or more layers, a distal end portion made of a conductor and provided, with respect to the coil section, at an end portion of the core material on a side where the other electrode is disposed, and a rear end portion made of a conductor and provided on the opposite side of the distal end portion with respect to the coil section. The rear end portion includes a first diameter section having a first diameter and a second diameter section having a second diameter smaller than the first diameter and present in a position farther from the coil section than the first diameter section.