A proposed search for dark-matter axions in the 0.6-16 micro-eV range

A proposed experiment is described to search for dark matter axions in the mass range 0.6 to 16 micro-eV. The method is based on the Primakoff conversion of axions into monochromatic microwave photons inside a tunable microwave cavity in a large volume high field magnet, as described by Sikivie. This proposal capitalizes on the availability of two Axicell magnets from the decommissioned Mirror Fusion Test Facility (MFTF-B) fusion machine at LLNL. Assuming a local dark matter density in axions of rho = 0.3 GeV/cu cm, the axion would be found or ruled out at the 97 pct. c.l. in the above mass range in 48 months

A 2nd generation cosmic axion experiment

An experiment is described to detect dark matter axions trapped in the halo of our galaxy. Galactic axions are converted into microwave photons via the Primakoff effect in a static background field provided by a superconducting magnet. The photons are collected in a high Q microwave cavity and detected by a low noise receiver. The axion mass range accessible by this experiment is 1.3-13 micro-eV. The expected sensitivity will be roughly 50 times greater than achieved by previous experiments in this mass range. The assembly of the detector is well under way at LLNL and data taking will start in mid-1995.Comment: Postscript, 6 pages, 4 figures; submitted to proceedings of: XXXth Recontres de Moriond, 'Dark Matter in Cosmology", Villars-sur-Ollon, Switzerland, Jan 21-28, 199

A Proposed Search for Dark-Matter Axions in the 0. 6--16. Mu. Ev Range

A proposed experiment is described to search for dark-matter axions in the mass range 0.6--16 {mu}eV. The method is based on the Primakoff conversion of axions into monochromatic microwave photons inside a tunable microwave cavity in a large volume high field magnet. This proposal capitalized on the availability of two Axicell magnets from the MFTF-B fusion machine at LLNL. Assuming a local dark-matter density in axions of {rho}{sub a}= 0.3 GeV/cm{sup 3}, the axion would be found or ruled out at the 97% c.1. in the above mass range in 48 months

Study of low-lying resonant states in 16F using an 15O radioactiveion beam

A 120 MeV {sup 15}O radioactive ion beam with an intensity on target of 4.5 x 10{sup 4} pps has been developed at the 88-inch cyclotron at the Lawrence Berkeley National Laboratory. This beam has been used to study the level structure of {sup 16}F at low energies via the p({sup 15}O,p) reaction using the thick target inverse kinematics method on a polyethylene target. The experimental excitation function was analyzed using R-matrix calculations. Significantly improved values for the level widths of the four low-lying states in 16F are reported. Good agreement with the theoretical spectroscopic factors is also obtained

First results from a second generation galactic axion experiment

We report first results from a large scale search for dark matter axions. The experiment probes axion masses of 1.3-13 micro-eV at a sensitivity which is about 50 times higher than previous pilot experiments. We have already scanned part of this mass range at a sensitivity better than required to see at least one generic axion model, the KSVZ axion. Data taking at full sensitivity commenced in February 1996 and scanning the proposed mass range will require three years

High precision branching ratio measurement for the superallowed β decay of [Formula Presented] A prerequisite for exacting tests of the standard model

Nonanalog Fermi and Gamow-Teller branches in the superallowed β decay of [Formula Presented] have been investigated using γ-ray and conversion-electron spectroscopy. Nine observed transitions, in conjunction with a recent shell model calculation, determine the branching ratio of the analog transition to be 99.5(1)%. The experimental upper limits for the Fermi decay to the [Formula Presented] and [Formula Presented] levels are in agreement with recent theoretical predictions. The [Formula Presented] value for the [Formula Presented] β decay is predicted to be 10405(9) keV. © 2003 The American Physical Society