Kurie plots

Figure 8.3 Example of a Kurie plot. (From Camp and Langer, 1963.) Notice that with a little rearrangement this spectrum can be represented as ...

If the nuclear matrix element does not depend on the electron kinetic energy, as we have assumed so far, then a plot of the reduced spectral intensity, the left-hand side, versus the electron kinetic energy will be a straight line that intercepts the abscissa at the Q value. Such a graph is called a Kurie plot, and an example is shown in Figure 8.3. This procedure applies to allowed transitions (see below). There are correction terms that need to be taken into account for forbidden transitions. 

Pure beta-emitting isotopes exist and may be used for calibration, but only after the energy spectrum is cast into a form called the Kurie plot. The beta spectrum is continuous and extends from zero energy up to a maximum end point kinetic energy (see Fig. 13.12). Because of the shape of the spectrum, it is impossible to accurately determine the end point energy. However, from the... 

Figure 13.12 A typical beta energy spectrum (solid line) and its Kurie plot (dashed line).

If the left-hand side of Eq. 13.12 is plotted against e, the result is a straight line that crosses the energy axis at = q. The Kurie plot is a straight line for allowed beta transitions. A forbidden beta decay will show an upward curvature at the end. ... 

Experimental and theoretical results can be easily compared by plotting the [N(p)/(.F ZE) P )f values as a function of Eq — E), as suggested first by Kurie et al. (1936). Figure 2.41 shows the Kurie plot for the P decay of The straight-line character of the plot indicates that the matrix element IMfil does not depend on the electron energy. The value of is near to one, as is usual with allowed transitions. For forbidden transitions (see later) may... 

---