D-Egg: a dual PMT optical module for IceCube

The D-Egg, an acronym for ``Dual optical sensors in Ellipsoid Glass Gen2,'' is one of the modules designed future extensions IceCube experiment at South Pole. D-Egg has elongated-sphere shape to maximize photon-sensitive effective area while maintaining a narrow diameter reduce cost and time needed drilling deployment holes glacial ice depths up 2700 meters. design utilized Upgrade, next stage project also known as IceCube-Gen2 Phase 1, where nearly half be deployed are D-Eggs. With two 8-inch high-quantum efficiency photomultiplier tubes (PMTs) per module, D-Eggs offer increased retaining successful digital module (DOM). convolution wavelength-dependent Cherenkov emission spectrum provides photodetection sensitivity that 2.8 times larger than DOMs. signal each PMTs digitized using ultra-low-power 14-bit analog-to-digital converters with sampling frequency 240 MSPS, enabling flexible event triggering, well seamless lossless recording single-photon signals multi-photons exceeding 200 photoelectrons within 10 nanoseconds. Mass production been completed, 277 out 310 produced used Upgrade. In this paper, we report des\ ign D-Eggs, single multi-photon detection performance mass-produced measured laboratory built-in data acquisition system sensor module.