An improved synthetic signal injection routine for the Haloscope At Yale Sensitive To Axion Cold dark matter (HAYSTAC)

Yuqi Zhu; M J Jewell; Claire Laffan; Xiran Bai; Sumita Ghosh; Eleanor Graham; S B Cahn; Reina H Maruyama; S K Lamoreaux

doi:10.1063/5.0137870

An improved synthetic signal injection routine for the Haloscope At Yale Sensitive To Axion Cold dark matter (HAYSTAC)

Rev Sci Instrum. 2023 May 1;94(5):054712. doi: 10.1063/5.0137870.

Authors

Yuqi Zhu^{1

2}, M J Jewell^{1

2}, Claire Laffan^{1

2}, Xiran Bai^{1

2}, Sumita Ghosh^{2

3}, Eleanor Graham^{1

2}, S B Cahn^{1

2}, Reina H Maruyama^{1

2}, S K Lamoreaux^{1

2}

Affiliations

¹ Department of Physics, Yale University, New Haven, Connecticut 06520, USA.
² Wright Laboratory, Department of Physics, Yale University, New Haven, Connecticut 06520, USA.
³ Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA.

PMID: 37249412
DOI: 10.1063/5.0137870

Abstract

Microwave cavity haloscopes are among the most sensitive direct detection experiments searching for dark matter axions via their coupling to photons. When the power of the expected microwave signal due to axion-photon conversion is on the order of 10-24 W, having the ability to validate the detector response and analysis procedure by injecting realistic synthetic axion signals becomes helpful. Here, we present a method based on frequency hopping spread spectrum for synthesizing axion signals in a microwave cavity haloscope experiment. It allows us to generate a narrow and asymmetric shape in frequency space that mimics an axion's spectral distribution, which is derived from a Maxwell-Boltzmann distribution. In addition, we show that the synthetic axion's power can be calibrated with reference to the system noise. Compared to the synthetic axion injection in the Haloscope At Yale Sensitive to Axion Cold dark matter (HAYSTAC) Phase I, we demonstrated synthetic signal injection with a more realistic line shape and calibrated power.