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Flex30R is an entry level real time digital correlator. It is the lowest cost
research grade digital correlator.
Flex30R specifications:
- Auto/cross correlations.
- 960ns minimum sample.
- 248 real time channels.
- Delay time range: 960ns to 1 hour in multiple tau channel layout.
- Input signal: standard TTL pulses.
- Two BNC connectors
- Easy to use FlexWindows software and software for Windows NT 4.0 and Windows95/98
libraries included.
Multiple tau channel layout ( sample time denoted at T, data width W):
- First 16 channels: T = 960ns, W = 5 bits, delay times T to 16*T;
- Second 8 channels: T = 2*960ns, W = 6 bits, delay times 9*T to 16*T
- Third 8 channels: T = 4*960ns, W = 7 bits, delay times 9*T to 16*T;
- Fourth 8 channels: T = 8*960ns, W = 8 bits, delay times 9*T to 16*T;
- Sample time doubles every 8 channels and data width increment 1 bit to prevent overflow.
- The longest delay time is about one hour.
Intensity limits:
Flex30R is designed with sufficient hardware resource to prevent overflow at any
reasonable intensities. However, in extreme situations, clipping and overflow could
happen. The intensity limits are following:
- Maximum intensity integrated over 960ns: 32.29 MHz. Intensity over the maximum
will be clipped to the maximum.
- Maximum intensity integrated over 251ms: 11.79 MHz. Overflow will happen if the
maximum is exceeded.
More about multiple tau theory.
Multiple tau theory was invented by Klaus Schätzel. The following papers discuss
the theory and the advantage of the multiple tau scheme.
- Klaus Schätzel. Single Photon Correlation Techniques. Dynamic Light
Scattering: The method and some applications, Edit by Wyn Brown, Clarendon Press, Oxford,
P 76, 1993.
- Klaus Schätzel et. Noise on Multiple-Tau Photon Correlation Data.
SPIE Vol. 1430, P109, Photon Correlation Spectroscopy: Multicomponent Systems,
1991.
- Klaus Schätzel. New Concept in Correlator Design. Inst. Phys. Conf. Ser. No.
77, P175, 1985.
- Klaus Schätzel et. Photon Correlation Measurements at Large Lag
Times. Journal of Modern Optics, Vol. 35, No. 4, P711, 1988.
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