The system of precise measurement of accelerator extraction efficiency

The extraction efficiency of the Fermi National Accelerator Laboratory synchrotron is determined by measuring the extraction inefficiency with a simple calibrated loss-measuring system. The relative inefficiency subtracted from unity gives a precise measurement of extraction efficiency from measurements made with only nominal precision. An uncertainly of +- 10% in the inefficiency measurement allows extraction efficiency of 99% to be known with an uncertainty of +-0.1%. The concept also can be used to intercalibrate accelerator internal and external intensity monitors and to indicate the amount of beam that may be lost elsewhere in a large accelerator. The concept, system and applications are discussed. (Auth.)