A SPICE Analysis of ILC Long-Ladder Noise
Physical and Biological Sciences
Physics thesis requirement - original undergraduate research
The long-ladder system is a proposed way to detect and precisely reconstruct the tracks of particles created in the International Linear Collider (ILC) – a planned machine that would collide electrons and positrons together in hopes of furthering our understanding of the most fundamental nature of the universe. We introduce a readout array that aimed to fulfill the tracking needs of an ILC detector, while reducing costs and materials of the experiment. Making use of solid state silicon sensors as a detection medium and our own LSTFE (long shaping time front end) chip to read out the signals, the long-ladder detector could reach lengths of up to 1 meter long, dwarfing its modern day precision-tracking counterparts of ~10 cm. Using a computer simulation benchmarked by prior laboratory measurements, we investigate the difference in performance between two models of the sensor: a naïve model in which the sensor's resistance and capacitance are each treated as a single separate (“lumped”) elements, and a more realistic model for which the sensor's resistance and capacitance are continuously distributed among one another. It is shown that the “network effects” that arise from the continuously distributed load significantly improve the detector signal to noise ratio relative to that expected for the naïve model, bolstering the case for the long-ladder option as a solution for Linear Collider tracking. We have also explored the possibility of further improvements in the signal-to-noise from reading the long-ladder sensor out from its center, rather than the conventional approach of end readout.
