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HK group is developing a dedicated electronics module

Hyper-Kamiokande utilizes Cherenkov light emitted by high-speed charged particles. When Cherenkov photons hit a photo-sensor in the Hyper-Kamiokande detector, an electronic pulse is produced. The integrated electric charge of the pulse is proportional to the amount of Cherenkov light, which is itself proportional to the momentum of the particle. The spatial distribution and timing distribution of the detected photons provides the position of the interaction and the direction of the produced particles. Therefore, it is necessary to use high performance electronic circuits to record the timing and charge from each photo-sensor. We are now developing a dedicated electronics module and evaluating its performance.

We have developed a custom charge-to-time converter (QTC) ASIC for Super-Kamiokande. This ASIC converts the amount of the input charge to a digital pulse, whose width is proportional to the integrated charge collected by the photo-sensor, and whose leading edge may be digitized by a TDC to determine the time the photo-sensor was hit.

LSI developed for Super-Kamiokande; CLC101(ICRR/IWATSU Electric Co. Ltd.)

In Hyper-Kamiokande, the QTC is considered as one of the primary options for instrumenting the detector. We are designing proto-type electronics board using the QTC ASIC for Super-Kamiokande. In order to measure timing, it is planned to implement the TDC function in an FPGA by programmable logic. The FPGA is commonly used in consumer products and recent development makes it possible to measure the timing very precisely. With the latest technology, the measurement accuracy is better than 10-10 seconds.

We are developing a proto-type module, which composed of these two elements with university and laboratories in the United States.

Evaluation board developed with the group in US.

We are also evaluating electronic readout based on an FADC (Flash Analog-to-Digital Converter), as another promising candidate for the signal processing. The FADC records the waveform of the input charge signal, sampling the waveform of the signal from the photo-sensor several million times per second. The recorded waveform is further processed digitally to precisely measure the timing and the charge of the signal. This system has been developed by the groups in Canada and Poland.

Through these developments, we are aiming to develop a signal processing system capable of handling signals from 50,000 photo sensors per Hyper-Kamiokande detector module, with goals of high performance, low power consumption and low cost per channel.

Evaluation board developed by the groups in Canada and Poland.