Dark Matter Detection: Innovations Inspired by Henry Cavendish's Experiment

The detector’s heart is a stack of concentric metal shells, each electrically isolated yet closely spaced. Inspired by Cavendish’s original setup for measuring electrostatic forces, this design focuses on spotting voltage differences caused by passing millicharged particles (mCPs). These particles carry fractions of an electron’s charge, making their effects incredibly subtle. Voltage shifts between shells form the measurable signature. Ultra-sensitive electrometers, capable of detecting microvolt-level changes or smaller, record these perturbations. Achieving such sensitivity demands rigorous shielding against electromagnetic interference, temperature swings, and mechanical vibrations—all of which threaten to mask the signal. Material purity and geometric precision are equally critical. The shells must be made from ultra-pure metals with minimal surface defects to prevent unwanted charge buildup. Spacing is optimized to maximize signal while minimizing capacitive effects that could dull sensitivity. Modeling suggests this setup could detect charges as small as one-thousandth of an electron charge under ideal conditions. Prototypes are expected within two to three years, initially aimed at benchmarking noise and calibration. Scaling up requires overcoming engineering hurdles like vacuum maintenance, long-term electrical stability, and clean electrometer integration. While cheaper than large accelerators, the design’s success depends on managing these challenges without compromising sensitivity.