Development of a Multi-Pixel Photon Counter Module with a Unified Interface

A new PET detector module which has a unified interface is proposed. The detector module consists of a scintillator array, a multi-pixel photon counter (MPPC) array and a front-end circuit. While a general PET detector module has three kinds of interface; power, control and data, the proposed detector has only one Ethernet cable. Power of the detector module is fed by a Power over Ethernet (PoE) method, which is configured to pass electric power along with data on twisted pair Ethernet cable. The clock used in the module is recovered from the serial data and the recovered clock is used to acquire and send the data back. The synchronization can be done using IEEE1588 or customized package with hardware assistance and software correction. Data are transmitted through User Datagram Protocol (UDP) to an uplink. The uplink can send the request with current timestamp to a module, the module responds in a fixed time delay, and the uplink detects the response and compare to the current timestamp. The difference detected by the uplink would be the fixed delay plus cable delay. Using proposed modules, it is expected flexible, scalable and upgradable systems can be easily constructed.