Cnostruction of an aparatus for Production and Detection of Axions by Using Optical Cavities

轴子是基本粒子标准模型或QCD（量子色动力学）在强CP问题中所要求的一种赝标Goldstone玻色子，也是当前宇宙学所预言的暗物质的重要候选者。我们建立了一个实验装置来产生和探测轴子，首先在强磁场中利用Primakoff效应将激光光子转化为轴子，然后在另一个磁场中利用Primakoff效应将激光光子转化为轴子，并对再生光子进行计数。我们介绍了一种新的实验方案，它采用两个由高反射率反射镜组成的光学谐振腔，一个用于第一次转换过程，另一个用于第二次转换过程，使转换效率乘以F_1F_2（Fi：第i个谐振腔的精细度）。预期的信号光子与（gBL）^4F_1F_2和耦合常数g成正比，磁场 ...更多信息 Bi（=B）和长度Li（=L）。来自激光器的相干光子进入第一光学谐振器，其中平行于光子的电场施加强磁场，并且一些光子被转换成轴子。由于轴子与材料之间的相互作用非常弱，轴子可以自由地穿过不透明的壁并进入第二光学谐振腔，而光子则完全被壁阻挡。轴子场是具有与光子场基本上相同的波长的相干波。一些轴子通过第二谐振器中的逆过程被转换成信号光子。两个谐振器被调谐到相同的波长。信号光子由第二个谐振腔后面的单光子计数器探测，初步实验在没有第二个谐振腔的情况下进行。在F=3 × 10 ^3、L= 0.97 m、B=1.0 T（永磁体）和Pin=50 mW的条件下，观察3.0 × 10 ^3 s没有信号。根据该结果，考虑到量子效率为0.1、光电倍增管的暗计数率为0.3s ^<-1>，以及其他实验参数，得到耦合常数的上限为g&lt;1.1x10^<-5>GeV^<-1>。少

The axion is a pseudoscalar Goldstone boson required by the standard model of elementary particle or QCD (the quantum chromo-dynamics) in connection with the strong CP-problem, and is also important as a leading candidate of the dark matter predicted by the current cosmology. However it has not been detected so far in spite of a lot of efforts.We constructed an experimental apparatus to produce and detect axions, in which firstly laser photons are converted into axions in a strong magnetic field via the Primakoff effect, secondly vice versa in another magnetic field and reproduced photons are counted. We introduced a new experimental scheme which employs two optical resonators composed of high-reflectivity mirrors, one for the first and the other for the second conversion processes, to multiply the conversion efficiencies by F_1F_2 (Fi : the finesse of the i-th resonator). The signal photons expected are proportional to (gBL)^4F_1F_2 with the coupling constant g, and the magnetic field … More Bi(=B) and the length Li(=L).Coherent photons from a laser enter the first optical resonator, where a strong magnetic field is applied parallel to the electric field of the photons and some of the photons are converted into axions. Because of extremely weak interaction between axions and materials, the axions go through an opaque wall freely and go into the second optical resonator, while the photons are completely blocked by the wall. The axion field is a coherent wave with substantially the same wavelength as the photon field. Some of the axions are converted into signal photons via the inverse process in the second resonator. Both of the resonators are tuned to the the same wavelength. The signal photons are detected by a single photon counter behind the second resonator.An preliminary experiment was performed without the second resonator. Under the conditions F=3 x 10^3, L=0.97m, B=1.0 T(permanent magnets) and Pin=50 mW,an observation for 3.0 x10^3 s gave no signals. From this result, considering the quantum efficiency of 0.1, the dark count rate of 0.3 s^<-1> of the photomultiplier, and other experimental parameters, an upper limit of the coupling constant was obtained as g<1.1x10^<-5> GeV^<-1>. Less