Low Leakage Switch Array for Ion Signal Detection for NνDEx

he detection of neutrinoless double- decay (0) holds profound implications for determining the Majorana nature of neutrinos and probing beyond the Standard Model physics. This study focuses on the critical challenge of weak signal detection in high-pressure gas time projection chambers (TPCs) in NDEx, where the ion drift velocity in high-pressure SeF6 gas necessitates extending the detectors recovery time to prolong its sensitive window for signal acquisition. We present the integration of a Low Leakage Switch (LLS) with the TopMetal CMOS sensor, designed to mitigate recovery currents and enhance slow-signal detection capabilities. The LLS employs Vds-regulated switches to minimize leakage to sub-0.6 fA levels, extending the time constant to several tens of secondssurpassing prior limits by one orders of magnitude of TopMetal-S. Experimental validation demonstrates the effective ion detection capability in the atmospheric environment by leveraging a microfocus X-ray source and a low leakage switch array. The results highlight the LLS-TopMetal integration as a transformative approach for next-generation Ion detectors.