The Search for the Cosmological Axion -- A New Refined Narrow Mass Window and Detection Scheme

TL;DR

This paper refines the search for axions by narrowing the mass window to 78.6-79.6 micro-eV around 19 GHz, proposing a detection scheme using a resonant cavity, Josephson amplifier, and resonant tunneling diode, based on the inverse Primakoff effect.

Contribution

It presents a more precise axion mass window and a novel detection scheme involving advanced RF components and the inverse Primakoff effect, building on previous proposals and simulations.

Findings

Narrowed axion mass window to 78.6-79.6 micro-eV.

Proposed a detection scheme with Josephson Parametric Amplifier and Resonant Tunneling Diode.

Reinforced previous mass estimates with new calculations.

Abstract

Based upon a previous axion mass proposal and detection scheme, as well as considering the axion mass ranges suggested by persuasive simulations in recent years, we present a revised axion/ALP search strategy and our calculations, concentrating on a slightly narrower axion mass (and corresponding Compton frequency) window in this report. The sole aim of this study was to provide a pin-point mass value for a resonant cavity detection scheme, and the outcome of calculations presented here reinforces the earlier mass window and the results (slightly different values from our calculations but within the same window) obtained by the calculations and simulations by Kawasaki et al. (2015) and Buschmann et al. (2020). The window comprises the spectral region of 18.99 to 19.01GHz (that falls within the Ku microwave band), with a center frequency of 19.00GHz (+0.1GHz), with equivalence to an axion mass range of 78.6 to 79.6 micro-eV, with the center mass at the value of 78.582 (+5.0) micro-eV, our suggested most likely value for an axionic/ALP field mass, if these fields exist. Our search strategy, as summarized herewith, is based upon the assumption that the dark matter that exists in the current epoch of our physical universe is dominated by axions and thus the local observable axion density is the density of the light cold dark matter, permeating our local neighborhood (mainly in the Milky Way galactic halo). Some ideas and the design of an experiment, based upon the inverse Primakoff effect, and built around a Josephson Parametric Amplifier and Resonant Tunneling Diode combination installed in a resonant RF cavity, are also some possibly novel ideas, as introduced in this report.