College Park, Maryland June 6 - 10 , 2004 |
M2-C2 (11:00 AM): Sub-Millisecond Time-Resolved Small-Angle Neutron Scattering
Charles J. Glinka (NIST Center for Neutron Research), Stephan Polachowski, J. Raebiger (FZ-Juelich)
A time-of-flight (TOF) technique at a steady state source proposed by Roland Gähler for time-resolved SANS measurements with sub-millisecond time resolution is currently being implemented on one of the 30-m SANS instruments at NIST’s Center for Neutron Research. The technique, labeled TISANE by Gähler, requires a high-speed disk chopper, preceding the instrument’s pinhole collimation, to pulse the beam at a frequency that is linearly related to the frequency (10 to 1000 Hz) of an applied field at the sample. In TOF terminology, the instrument operates in the far frame-overlap regime such that neutrons from several successive pulses arrive at the detector at a particular time corresponding to a definite (sub-millisecond) time interval within the period of the applied field at the sample.
The plan for implementing TISANE on the NIST/NSF 30-m SANS instrument on guide NG-3 at the NCNR and its current status will be described along with estimates of the attainable time-resolution (~ 50 μsec). Possible applications for the technique in macromolecular systems and structured fluids will be discussed.
Back to the Program