Fast-Acting Valve

In areas of the Zero Gradient Synchrotron (ZGS) accelerator where high energy proton beams or other nuclear particles are extracted from the interior of the synchrotron into experimental areas, thin mylar or aluminum windows are used to minimize energy losses. Rupture of these windows (as large as nine inches in diameter) could cause considerable damage. A 9-inch, fast-closing valve has been designed and a prototype has been built and tested. The valve can operate in vacuum or at atmosphere. Closure of the valve requires no circuits, signals, or mechanical actuators, but rather is activated by the energy of the inrushing gas itself. An electrically triggered clutch arrangement can be incorporated for mechanical closing, if so desired, with no interference when the fast mode of closure is necessary. The results of the fast mode of closure indicate closing times of 17 to 30 ms. "Blowby," before closure of the valve is completed, is approximately 2. 5 ft3 of air (at one atmosphere). With such a valve, the entire ring vacuum system will not reach pressures greater than 300 microns (0. 3 mm Hg), should a 9-inch diameter window rupture.