Real-Time Data Acquisition and Processing System Design for the ITER Radial Neutron Camera

The Radial Neutron Camera (RNC) of ITER is a collimated multichannel neutron detection system intended to characterize fusion plasma neutron source. The RNC diagnostic plays a primary role in the ITER Program for advanced control measurements and physics studies. It also acts as backup system by providing machine protection and basic control measurements. The aim of ITER is to prove the viability of fusion as an energy source and to collect the data necessary for the design and subsequent operation of the first electricity-producing fusion power plant. The expected ITER pulse duration is up to 500 s in the inductive scenario. The demanding ITER operating conditions require a real-time Data AcQuisition and Processing (DAQP) system that will acquire analog signals from the RNC detectors (e.g. scintillators, CVD diamonds, fission chambers) providing digital data throu2gh high performance networks to the ITER database. Two DAQP systems are expected to be used as prototypes for preliminary tests of performance: one based on PCI Express Extensions for Instrumentation (PXIe) and another one based on Advanced Telecommunications Computing Architecture (ATCA). The ATCA based system, with an architecture capable of withstanding a sustainable throughput of the order of 0.5 GB/s of data per channel, will be presented. The system features high performance Field Programmable Gate Arrays (FPGA) for every two 12 bits channels, sampling up to 1.6 GSPS and high performance host computers for every 4 channels through ×16 PCIe 2.0 links. The criteria used for the choice of the components of both systems, ATCA and PXIe take into account: i) data throughput; ii) realtime data reduction; iii) compression, and iv) pulse processing. Finally, the expected data throughput performance of both architectures will be discussed.