The muon anomalous magnetic moment has been measured in a new experiment at Brookhaven. Polarized muons were stored in a superferric ring, and the angular frequency difference, v a , between the spin precession and orbital frequencies was determined by measuring the time distribution of highenergy decay positrons. The ratio R of v a to the Larmor precession frequency of free protons, v p , in the storage-ring magnetic field was measured. We find R 3.707 220͑48͒ 3 10 23. With m m ͞m p 3.183 345 47͑47͒ this gives a m 1 1 165 925͑15͒ 3 10 29 (613 ppm), in good agreement with the previous CERN measurements for m 1 and m 2 and of approximately the same precision.

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The RHIC Beam Loss Monitor (BLM) System is designed to prevent beam loss quenching of the superconducting magnets, and acquire loss data. Four hundred ion chambers are located around the rings to detect losses. The required 8-decade range in signal current is compressed using an RC pre-integrator ahead of a low current amplifier. A beam abort may be triggered if fast or slow losses exceed programmable threshold levels. A micro-controller based VME module sets references and gains and reads trip status for up to 64 channels. Results obtained with the detectors in the RHIC Sextant Test and the prototype electronics in the AGS-to-RHIC (AtR) transfer line are presented along with the present status of the system. THE DETECTORS AND ELECTRONICSIt has been estimated that the RHIC superconducting magnets will quench for a fast (single turn) loss > 2 mJ/g or a slow (100 msec) loss > 8 mW/g. These correspond to a signal current range from 5.5 mA for fast loss at injection, and 17.6 nA for a slow loss at full energy. Allowing for studies, a dynamic range of 8 decades in detector current is required. The processed BLM signal is digitized at 720 Hz and continually compared to programmable fast and slow loss abort levels. An abort halts data acquisition providing a 10 second loss history. BLM parameters may be adjusted to set gains, fast and slow loss thresholds and abort mask bits on specific RHIC Event Codes.The RHIC Ring BLM system uses 400 FNAL Tevatron type ion chambers [1] modified by using an isolated BNC to break the ground loop formed by the signal and HV cable shields. Rexolite rather than PTFE is used for the insulators in the BNC and SHV connectors to improve the radiation hardness. The ion chamber[2] consists of a 113 cc glass bulb filled with argon to about 725 milli-Torr. Each chamber is calibrated using a cesium-137 source. The mean sensitivity in the middle of the plateau (1450 Volts) is 19.6 pA/rad/h, with 95% within ±1.5 pA/rad/hr of the mean. The high voltage is normally set to 1450 V with a 3000 V upper limit. Half of the ion chambers (198) are mounted on the quadrupole cryostats between the Rings using stainless steel "belly bands". Ninety-six *Work supported by the US Department of Energy ‡ witkover@bnl.gov BLMs are placed at insertion region quads. In the warm regions, 68 detectors are mounted on the beam pipe at sensitive loss points. In addition, 38 BLMs are available as re-locatable monitors.Belden 9054, a low noise, non-tribo-electric RG-59 equivalent cable was used for signal transmission. The HV bias voltage is carried on red RG-59 cable which is daisy-chained from detector to detector. Two HV cables are used in each sector, picking up alternate BLMs to provide some redundancy in the event of a high voltage short. An RC network built into each ion chamber housing provides decoupling in the case of a short, noise filtering, and storage capability to handle large fast losses.The analog electronics are packaged in VME modules, each of which interfaces to 8 BLMs. Up to 8 analog boards are m...

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