1. Operation and Control of 42 GHz Gyrotron system in ECRH
Summery
42GHz Gyrotron system is in operation with aditya and sst1 tokamak using PXIe based Data Acquisition and Control system. ECRH pulse of ~70-250kW, ms duration has been tested on dummy load and tokamak.
Fast protection circuit with FPGA board has improved the safety concern of gyrotron tube. Implementing digital filters within fpga logic avoids any spurious intakes at fault signal inputs of FPGA board really enhances the reliability of fast interlock operation with real faults.
We noticed that NI labVIEW has certain data size limits ( upto 16MBytes) to display data on plots depending upon the PC memory and speed of processor. Plotting more data size ( > 16 Mbytes) gives overrun buffer error. Partitioning large data in 100 second slot size and scroll to next slot and display technique helped to update display.
Fast data acquisition module (PXIe6356) acquires data of selected channels for fault analysis at 1 MHz sampling rate ( 100 ms pre- post trigger ) when FPGA board recognize the fault occurence in the system. It helps to analyze the sequence of fault occurence.