The first use for Xenon was in flash lamps used in photograph and it is still used for this purpose today. It is also used in strobe lights and some bactericidal lamps. This same technology also led to the invention of the first solid-state laser in 1960. Today xenon is used in excimer lasers, which are used for producing computer chips and in laser eye surgery. Xenon is also used in xenon arc lamps. These lamps are used in solar simulators, film projectors, HID lamps, some night vision systems and high end flashlights. Xenon is also used in sodium vapor lamps as a starter gas. A mixture of xenon and neon is used in the cells of plasma televisions. Xenon gas, mixed with oxygen and air, is also used as a general anesthetic and is administered with an anesthesia machine. The medical industry also utilizes two very important isotopes of Xenon, 133X and 129X. 133X is used in nuclear medicine to image vital organs such as the heart, brains and lungs. It can also be used to measure blood flow. 129X is used as a contrast agent in MRI scans. Xenon is also used in bubble chambers and calorimeters, which are used for experiments. It is also used as a propellant in spacecraft that use ion propulsion.