Design Up-gradation of Electronics for PMT Sensor based Systems in ADITYA-U Tokamak

Photo multiplier tube (PMT) detector-based spectroscopy diagnostic has been installed for plasma physics experiments in ADITYA-U Tokamak. The output of PMT is current pulse ranging from 100nA-50µA depending upon the light detected from plasma. To condition this current signal to a level compatible with data acquisition system (DAQ) for further processing, analog signal conditioning electronics (SCE) has been designed and commissioned in ADITYA-U Tokamak at Institute for Plasma Research (IPR). SCE is a vital interface between detectors/sensors and the Data-acquisition and control system. Typical stages of SCE include current to voltage conversion, voltage amplification, filtration, galvanic isolation, impedance transformation, level translation. As electronics has to operate in high electric and magnetic field environment of Tokamak, special care needs to be taken in design and development of signal conditioning electronics to achieve accuracy in measurement. In ADITYA Tokamak, we had developed a 6U size chassis-based SCE system for PMT based spectroscopy diagnostic. ADITYA Tokamak in Institute has been upgraded to ADITYA-U Tokamak. The spectroscopy diagnostic requirement has also been upgraded. The electronics has also been upgraded in design and topology to improve signal to noise ratio, increase the channel density, lower the power consumption and easy to maintain. The paper presents new electronics of Adity-U Tokamak.