Exploring the Epoch of Reionization: Verifying a Capacitive Displacement Sensor for the EoR-Spec on FYST

One of the main science goals of the Fred Young Submillimeter Telescope (FYST) is to investigate the sources of ionization that ionized the universe during the Epoch of Reionization (EoR). To do this, mounted onto FYST is the instrument module: Epoch of Reionization Spectrometer (EoR-Spec). EoR-Spec will use Line Intensity Mapping (LIM) to observe fine-structure lines of ionized carbon [CII].

To observe [CII], a Fabry-Perot Interferometer (FPI) is used to scan over frequencies corresponding to its 2nd & 3rd orders: 210 GHz to 315 GHz, 315 GHz to 420 GHz, respectively.

In order for the FPI to work correctly, the gap size, parallelism of the mirrors of the FPI, and scanning steps must be kept to a high precision. To monitor these factors we will use the Micro-Epsilon (M-E) capacitive sensors. We report on the verification of the Micro-Epsilon capacitive sensors to achieve this precision and accuracy through tests comparing displacement gaps of the FPI itself and the gap measured by the M-E sensor.