The Anti-Mass Spectrometer is a room-sized piece of equipment located in Sector C's Test Lab C-33/a at the Black Mesa Research Facility that is used to analyze exotic materials such as Xen crystals. It was designed by Dr. Rosenberg.
Operation of the machinery requires cooperation between a number of people, including control rooms, test chamber, and sample storage personnel. First, from the lower level, power to the device has to be switched on and the desired intensity (up to 80%) has to be set; in the main test chamber, the rotors have to be started. Stage one and two emitters are then powered on from the main control room and begin to produce visible beams. The monitoring personnel can increase the intensity of the Spectrometer, but the equipment was not designed to be run at more than 90% as doing so nullifies the safety buffer. Samples are brought into the upper test chamber by a lift from the lower levels and are held by a cart to be pushed by a person into the Spectrometer's beam. The containment system with dampening fields prevents a Resonance Cascade from occurring. Although they can be manually turned off, doing so produces a noticeable discrepancy in the displacement flow indicators.
Despite the high levels of energy used in the experiments (running the spectrometer requires the use of HEV Suits, and in Half-Life: Blue Shift the process is shown to place visible strain on the entire facility's power sources), it was a typically safe procedure. The final experiment of the Black Mesa Anti-Mass Spectrometer, combining a highly unstable sample and the disabling of certain safety features, triggered a Resonance Cascade and was the opening event of the Black Mesa incident. The Anti-Mass Spectrometer was heavily damaged during the Resonance Cascade, but not actually destroyed until Black Mesa itself was detonated.
Behind the scenes
The main test chamber seen in Half-Life was built by Brett Johnson, Kelly Bailey, and John Guthrie, with the latter two creating the disaster sequence. The original script for the test chamber sequence by Marc Laidlaw can be found in Half-Life 2: Raising the Bar; one of the scientists was to allude to the Spectrometer causing infertility. It is possible that the analyzer was to explode when the player waited too long during the experiment (see c1a0_sci_dis17a, an unused line by a scientist in the control room).
Richard Keller in the lower Anti-Mass Spectrometer Control Room.
The Materials Handler inside the delivery system.
A faint depiction of a partially redone Anti-Mass Spectrometer test chamber during the opening sequence of Half-Life 2.