Universal pulse, shaped

The last three pulses listed in table 1, namely the two E-BURPs and the are non-universal pulses designed to transfer Zeeman polarization Iz) into detectable transverse magnetization I or ly), but not to achieve the reverse operation. The conversion of or ly into Iz can be achieved by using the time-reversal of the considered pulse shape. An alternative... 

As described in the section on nonlinear absorption, the transmission of a pulse which is short compared to the various molecular relaxation times is determined by its energy content. A measurement of the energy transmission ratio will then give the peak intensity of the pulse when its pulse shape is known 44>. In fact, the temporal and spatial pulse shape is of relatively little importance. Fig. 11 gives the energy transmission as a function of the peak intensity I [W/cm2] for the saturable dye Kodak 9860 with the pulse halfwidth as a parameter. It is seen that this method is useful in the intensity region between 10 and 1010 MW/cm2 for pulses with halfwidths greater than 5 to 10 psec. Since one can easily manipulate the cross-section and hence the intensity of a laser beam with a telescope, this method is almost universally applicable. 

Salonen, L. 1993. Measurement of low levels of 222Rn in water with different commercial liquid scintillation counters and pulse shape analysis. In J.E. Noakes, F. Schoenhofer, and H. A. Polach (eds), Advances in Liquid Scintillation Spectrometry 1992, pp. 361-371.Tucson Radiocarbon Publishers, University of Arizona. 

It is not possible to lay down any universal rules since receptivities vary widely and relaxation times may be very long, especially for Li, or extremely short. Where the relaxation times are not too long, data are easy to obtain in the FT mode and the disadvantages of shorter relaxation times and broad lines can often be overcome to a great extent since short acquisition times and rapid pulse repetition rates are permissible, especially if some line-shape distortion can be tolerated. For maximum use to be made of such techniques access to memory sizes less than IK must be possible. 

---