gas maser

A gas maser is a device that produces and amplifies electromagnetic radiation in the microwave range. The name "maser" is an acronym for "microwave amplification by stimulated emission of radiation". Gas masers, such as those using ammonia or hydrogen, utilize electric fields to select excited atoms or molecules for amplification. The atomic hydrogen maser, developed in 1960, is a highly accurate standard for frequency and time, with a clock controlled by it losing no more than a second in 100,000 years. Gas masers have been crucial in scientific advancements, including measuring faint radio waves from planets like Venus to determine their temperature. The maser is considered a precursor to the laser.1