Integration of the TeraVoxel infrastructure with
laboratory facility and instrumentation control was
first implemented in support of an experiment targeting
the study of the dispersion of a passive scalar contaminant
in (nearly) homogeneous turbulent flow.
movie coming soon!
|
KFS CAMERA
As part of the laboratory-support, we will extend the
capabilities of the recently developed, 10242-pixel KFS
digital-imaging system to higher speeds (103 frames/s; 109 voxels/s)
and field-data storage (1.7Tbytes). -from TVXL proposal
The KFS camera system was designed and fabricated in-house for low-noise high-speed
measurements of turbulent flow and mixing. The KFS camera head contains a low-noise
CCD (KFS CCD) designed at JPL by Mark Wadsworth. The KFS CCD has a resolution
of 1024x1024 12 m2 pixels and has 32 output channels. The KFS camera system has
programmable voltage levels and clock timings to optimize the CCD performance. The
32 CCD output channels are buffered and fed to 8 A/D converter board (VXIADC2) (see
diagram below). Each A/D converter board has four 12-bit 40-MHz A/D converters for a
total of 32 channels. Real-time lossless image compression reduces image storage
requirement by 1.5 to 3 times. Each A/D board has 512 megabytes of double-buffered
memory for a total of 4 gigabytes of local image storage (enough for approximately 3000
to 6000 frames). The KFS camera system has a measured noise of 25.8 e at 200
frames/second. The camera system is controlled by a PC running Windows XP.
Each A/D converter board has a high-speed auxiliary I/O port. This port is used to
interface to an S-Link fiber-optic link. The S-Link is a High-speed, low overhead fiberoptic
link developed at CERN. The S-Link has a transfer rate of up to 160
megabytes/second, giving a maximum of 1.28 gigabytes/second for 8 channels. The SLink
is used to transfer real-time data to the Datawulf storage clusters. This allows for
the acquisition of terabytes of data, limited only by the speed of the disk arrays on the
Datawulf machines. The 512 MB local memory is used as a double buffer between the
A/D converters and the S-Link. A sustained transfer rate of 200 fps (frames/second),
corresponding to 40 MB/sec/channel, x8 channels, for a total of 300,000 frames, was
demonstrated with no data loss.
|
