PDF《MPP-2016-141》

100 ?eV mass axions. It consists of a series of parallel dielectric disks with a mirror on one side, all within a magnetic ?eld parallel to the surfaces as shown in Fig. 1―a dielectric haloscope. For large ma the greatest hindrance for conventional haloscopes is that the signal is proportional to the cavity volume V . With dimensions on the order of the axion Compton wavelength1 λa = 2π/ma, V ∝ λ3 a which de-

1 We use natural units with = c =

1 and the Lorentz-Heaviside convention α = e2/4π. arXiv:1611.05865v2 [physics.ins-det]

3 Mar

2017 2 creases rapidly with ma. While there are plans to cou- ple multiple high-quality cavities, use open resonators, or compensate with extremely high magnetic ?elds and/or new detectors, these techniques may not prove practical for large ma [17, 22C24]. A radical approach to increase the volume is to use a dish antenna (i.e., a mirror) inside a B-?eld to convert axion DM into microwaves [25]. The resonantly enhanced axion-photon conversion is then given up in favour of a large transverse area A λ2 a. In our dielectric haloscope each disk emits electromag- netic (EM) waves similar to the mirror case. As the disks are semi-transparent, the waves emitted by each disk are re?ected by and transmitted through the other disks before exiting. With suitable disk placemen........