Speaker
Description
The Higgs physics goals of the future Higgs factories demand unprecedented precision. Monolithic Active Pixel Sensor (MAPS) technology applied to tracking and electromagnetic calorimetry (ECal) has excellent potential to achieve this precision. This technology offers high granularity, thin sensors, fast responses ($<$nsec), and small dead areas. Colliders with low duty cycles enable gaseous cooling for tracking and passive heat removal for calorimetry. This effort derives from the plans for the SiD concept originally conceived for the ILC.
A MAPS prototyping effort (NAPA-p1) led by SLAC in collaboration with CERN is aimed at the tracking requirements, with complementary application to the ECal requirements. The first MAPS prototype, designed in CMOS imaging 65 nm technology, is under test. The long-term objective is a wafer-scale sensor of area 5 × 20 cm$^2$. Small pixels significantly improve shower separation in the ECal. Detailed simulation of ECal performance confirms previous results, indicating electromagnetic energy resolution based on digital hit cluster counting provides better performance than the 13 mm$^2$ pixels SiD TDR analog design. Furthermore, two particle separation in the ECal is excellent down to the millimeter scale. Geant4 simulation results with optimized analysis based on machine learning has been studied to optimize these expectations. Simple thermal analysis suggests passive cooling is adequate for low duty cycle colliders.
