29th Symposium on Fusion Technology (SOFT 2016)

P2.058 Implementation of Rapid Imaging System on the COMPASS tokamak

6 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 58

Poster D. Diagnostics, Data Acquisition and Remote Participation P2 Poster session

Speaker

Ales Havranek (Institute of Plasma Physics of the CAS)

Description

The COMPASS tokamak has been recently equipped with two new fast color cameras Photron FASTCAM Mini UX100 operating in visible light. A new node, including both software and hardware, was developed for these cameras to ensure automatic and reliable operation integrated to the control and data acquisition system of COMPASS. The node provides camera function control, parameter setting, data transfer from the camera to PC, demosaicing, encoding of a preview video, data saving to the COMPASS database and managing of a disk space. The FASTCAM Mini UX100 camera operates at a full frame resolution of 1280 x 1024 pixels up to 4 kfps and is capable of achieving frame rates as high as 800 kfps at a reduced frame resolution of 640x 8 pixels. The camera uses 12-bit CMOS sensor with 10 µm square pixels allowing minimum exposure time of 1µs (shutter speed). A standard Bayer mask is used for color imaging. Images are collected to 4 GB internal memory, which limits maximum recording time. Node’s software is divided into three parts. The first part is programmed in C++. It takes care of direct communication with cameras, their control and raw mosaic data collecting. Then, raw data are stored to HDF5 files. The second part, written in Java, provides shot sequence control, cameras setting transfer, raw and video data transfer to the COMPASS database and disk space management. The third part demosaics raw data, processes and encodes a video. We use free open-source software AviSynth with our in-house plug-in that reads HDF5 files and demosaics it. The video is encoded with the MPEG-4 H.264 codec. Node’s hardware consists of the cameras equipped with a wide-angle lens combined with relay lenses, network accessories and the computer, all optically insulated from other tokamak systems. We introduce all mentioned subsystems implemented on COMPASS.