Absolute pressure and gas species identification with an optically levitated rotor
Absolute pressure and gas species identification with an optically levitated rotor
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DOI：
10.1116/1.5139638
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发表时间：
2020-03-01
影响因子：
1.4
通讯作者：
Gratta, Giorgio
中科院分区：
文献类型：
--
作者：
Blakemore, Charles P.;Martin, Denzal;Gratta, Giorgio
作者描述了一种新型的旋转转子真空计，其中转子类似于4.7 μ m直径的二氧化硅微球，光学悬浮。旋转静电场用于向二氧化硅微球的永久电偶极矩施加扭矩并控制其旋转自由度。当从驱动场释放时，微球的角速度随着阻尼时间呈指数衰减，阻尼时间与残余气体压力成反比并且取决于气体成分。通过静电共悬浮测量转子质量，并假设球形，单独确认和均匀密度来校准压力计。通过观察由许多不同气体种类引起的扭转阻力，将压力计与电容压力计进行交叉检查。由于微球的小尺寸和在三维中平移光阱的能力，以及在磁场环境中的测量，所提出的技术可以用于执行空间中局部化的绝对真空测量。此外，微球的动力学，与校准的真空计配对，可用于测量气体混合物的有效分子量，而无需电离，压力高达约1毫巴。
The authors describe a novel variety of spinning-rotor vacuum gauge in which the rotor is asimilar to 4.7 - mum -diameter silica microsphere, optically levitated. A rotating electrostatic field is used to apply torque to the permanent electric dipole moment of the silica microsphere and control its rotational degrees of freedom. When released from a driving field, the microsphere's angular velocity decays exponentially with a damping time inversely proportional to the residual gas pressure and dependent on gas composition. The gauge is calibrated by measuring the rotor mass with electrostatic co-levitation and assuming a spherical shape, confirmed separately, and uniform density. The gauge is cross-checked against a capacitance manometer by observing the torsional drag due to a number of different gas species. The techniques presented can be used to perform absolute vacuum measurements localized in space, owing to the small dimensions of the microsphere and the ability to translate the optical trap in three dimensions, as well as measurements in magnetic field environments. In addition, the dynamics of the microsphere, paired with a calibrated vacuum gauge, can be used to measure the effective molecular mass of a gas mixture without the need for ionization and at pressures up to approximately 1mbar.