Engineering topics

Ruppert, S.

Publications and source records attributed to Ruppert, S..

3 records

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↗

DOE OSTI2012

SPE3 Far-field Quicklook

The purpose of this report is to provide an overview of the seismic data collected during the SPE3 chemical shot. Farfield seismic data includes data collected at distances of more than 100 m from the shot and instruments deployed for the experiments. This report does not address infrasound, remote sensing, or seismic data collected by regional permanent stations. The primary goal is a fast data check before extensive analysis. The SPE3 shot was conducted on July 24, 2012 (DOY 206) at the SPE test site and in the same borehole as SPE1 and SPE2 (table 1). Data processing at LLNL primarily used mini-seed data volumes downloaded from the UNR server along with associated metadata. This is in contrast to earlier shots, where LLNL data was based on reformatted Reftek data. Sensor deployment was similar to previous shots, with a few changes. Parts of lines 1 (13, 14, 15, 16), 3 (23,26,36), and 5 (1-12) were recorded by telemetry as well as to disk, which provided immediate access to the data. A small array (6 station) geophone array was deployed southeast of the shot near AF9 to measure particle motions. A new rotational sensor (ATA ARS-16) was deployed at station L3-20.

58 GEOSCIENCES↗