An Instrument for Bone Mineral Measurement Using a Microprocessor as the Control and Arithmetic Element
We have developed a self-contained instrument for the determination of bone mineral content by photon absorptometry. A high-resolution detection system allows measurements to be made at up to 16 photon energies. Control and arithmetic functions are performed by a microprocessor. Analysis capability and limitations are discussed.
Measurement of Bone Mineral in vivo: An Improved Method
The mineral content of bone can be determined by measuring the absorption by bone of a monochromatic, low-energy photon beam which originates in a radioactive source (iodine-125 at 27.3 kev or americium 241 at 59.6 kev). The intensity of the beam transmitted by the bone is measured by counting with a scintillation detector. Since the photon source and detector are well collimated, errors resulting from scattered radiation are reduced. From measurements of the intensity of the transmitted beam, made at intervals across the bone, the total mineral content of the bone can be determined. The results are accurate and reproducible to within about 3 percent.
Parameters for low energy operation of CESR
We present a detailed design for operation of the Cornell Electron Storage Ring, CESR, in the energy range covering the /spl psi/ resonances and the Charm and Tau thresholds, as well as reaching to the upper Y resonances near 11 GeV. The addition of 18 m of super-ferric wiggler magnets will partially restore low energy beam emittance and damping times. Installation of superconducting quadrupoles in the interaction region and the addition of high performance superconducting RF cavities will enhance performance at all energies. Studies of optics, beam dynamics, wiggler and vacuum system performance, beam stability, and beam-beam effects confirm operation with a luminosity of 3/spl times/ 10/sup 32/ CM/sup -2/ sec/sup -1/ at 1.88 GeV.