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Goodman, C.

Publications and source records attributed to Goodman, C..

4 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

ADMX Axion Dark Matter Bounds around 3.3 μ eV with Dine-Fischler-Srednicki-Zhitnitsky Discovery Ability

We report the results of a QCD axion dark matter search with discovery ability for Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) axions using an axion haloscope. Sub-Kelvin noise temperatures are reached with an ultralow noise Josephson parametric amplifier cooled by a dilution refrigerator. This work excludes (with a 90% confidence level) DFSZ axions with masses between 3.27 to 3.34 μ eV , assuming a standard halo model with a local energy density of 0.45 G e V / cm 3 made up 100% of axions. Published by the American Physical Society 2025

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

Search for non-virialized axions with 3.3-4.2 $\mu$eV mass at selected resolving powers

The Axion Dark Matter eXperiment is sensitive to narrow axion flows, given axions compose a fraction of the dark matter with a non-negligible local density. Detecting these low-velocity dispersion flows requires a high spectral resolution and careful attention to the expected signal modulation due to Earth's motion. We report an exclusion on the local axion dark matter density in narrow flows of $\rho_a \gtrsim 0.03\,\mathrm{GeV/cm^3}$ and $\rho_a \gtrsim 0.004\,\mathrm{GeV/cm^3}$ for Dine-Fischler-Srednicki-Zhitnitski and Kim-Shifman-Vainshtein-Zakharov axion-photon couplings, respectively, over the mass range $3.3-4.2\,\mu\text{eV}$. Measurements were made at selected resolving powers to allow for a range of possible velocity dispersions.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1971

Characteristic temperatures of the Mossbauer fraction and thermal-shift measurements in iron and iron salts.

Measurement of Mossbauer spectra in metallic iron, sodium nitroprusside, sodium ferrocyanide, and potassium ferrocyanide absorbers between 78 and 293 K. The temperature dependences of the Mossbauer fraction and the resonant velocity were fitted to Einstein and Debye lattice-vibration models. The characteristic temperatures of the models fitted to the Mossbauer fraction are consistently lower than those fitted to the resonant velocity showing the sensitivity of the Mossbauer fraction to low-frequency modes of vibration. The characteristic temperatures obtained from the resonant velocity are higher for the salts than for the metal, indicating the presence of higher-frequency modes in the salts. This interpretation is verified semiquantitatively by comparing the thermal-shift Debye temperatures of the salts to their infrared absorption frequencies. The Mossbauer fraction of potassium ferrocyanide shows a weaker temperature dependence than that expected for a harmonic solid, which suggests that potassium ferrocyanide is anharmonic in the temperature range studied.

Lafleur, L. D.↗