Mark S. Brown edited Other20mmResults.tex  over 10 years ago

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\subsubsection{Other LSO:CeCa 20mm Results}  In table \ref{tab:ctrfit-20-results} we again perform the two fittings. polynomial fits.  In this case both the fit to the intercept and to a linear relationship perform well. We also see that Again  the peak-to-peak change standard deviation  is on the other order  of the error in the intercept values. From these second set of measurements we would intercept$_\text{notfit}$. We  conclude no relationship between the  CTR and the  DOI is evident,  within error.This is despite these measurements resulting in a a lower error per CTR measurement and a greater number of $\gamma\gamma$ events recorded; namely 5000 compared to 3400.  In figure \ref{fig:centroidposition-20} the same plateau as observed in the 30mm measurements is again seen. In this case the plateau is reached close to 10mm for the wrapped measurements. Again the peak to peak range in the delay peak centroid is comparable to the scintillator crystal length. We can conclude that the shift is predominantly dependent upon the geometry of the scintillator crystal.   In figure\ref{fig:energyresolution-20} we see the energy resolution improve with increasing DOI. In figure  \ref{fig:lightoutput-20} we see the right photopeak centroid with DOI. We see that In this case  the energy resolution is poorest plateau commences  at low DOI; (or near to) 10mm. As  this despite has changed with scintillator crystal length  the light output being higher at low DOI. The improvement in geometry is clearly  the energy resolution from unwrapped primary contribution due  to wrapped is as expected corresponding this effect. The peak  to peak ranges are different between configurations. Namely 120$\pm$12ps, 162.2$\pm$1.7ps and 130.7$\pm$1.5ps for  the increase in unwrapped, partially wrapped and wrapped configurations. In  the light output. As 30mm case these values are 227.9$\pm$2.5ps and 223.3$\pm$2.5ps for  the increase in unwrapped and wrapped configurations respectively. We conclude two things:     \begin{enumerate}   \item Larger peak to peak range on  the light output partially wrapped case  is large when covering the face opposing due to...   \item The unwrapped and wrapped configurations have  the photodetector, it is clearly important that in real usage it is ensured that a proper PTFE wrap is in place same peak  to maximise timing and energy performance. peak range because...   \end{enumerate}