The authors demonstrate detection and mapping of brain magnetic fields evoked by auditory stimulation with a noncryogenic magnetometer based on spin precession of potassium atoms in spin-exchange-relaxation-free regime. Optical readout using a photodiode array allows flexibility in detector placement while using common elements for most components of the multichannel system. Absence of a cryogenic dewar eliminates magnetic Johnson noise from radiation shields and allows the use of a compact magnetic shield with a high shielding factor. The magnetometer sensitivity is currently equal to 3.5 fT/Hz~(1/2) at 10 Hz, similar to superconducting quantum interference device magnetoencephalography systems.
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机译:作者展示了在无自旋交换松弛的条件下,基于钾原子自旋进动的非低温磁力计,通过听觉刺激诱发的脑磁场的检测和作图。使用光电二极管阵列的光学读出可以灵活地放置检测器,同时对多通道系统的大多数组件使用通用元件。无低温杜瓦瓶消除了辐射屏蔽罩的磁性Johnson噪声,并允许使用具有高屏蔽系数的紧凑型磁性屏蔽罩。目前,磁强计的灵敏度在10 Hz时等于3.5 fT / Hz〜(1/2),类似于超导量子干扰设备的脑磁图系统。
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