this is for holding javascript data
Mark S. Brown edited 20mm Measurements.tex
over 10 years ago
Commit id: 18f1bba6bb14a4cb9fc4eb5f47371ee6faa6cfa0
deletions | additions
diff --git a/20mm Measurements.tex b/20mm Measurements.tex
index 3ba2776..6c52520 100644
--- a/20mm Measurements.tex
+++ b/20mm Measurements.tex
...
In figure \ref{fig:confinement-20} the confinement is consistent across all DOI except for the unwrapped configuration. In this case we see a gradual drop off in the number of $\gamma\gamma$ events recorded with increasing DOI. This is due to poor vertical alignment. Due to this, the confinement region lies to the side of the scintillator crystal at higher DOI not within it. In figure \ref{fig:ctrdoi-20} we see that this results in an increasingly larger error in the CTR until not enough events are collected to accurately determine the value at all. Even so, we find that poor alignment whilst degrading the error in the measurement, does not introduce a systematic shift into the CTR. Thus as long as the number of $\gamma\gamma$ events collected is high then alignment is not a critical parameter.
In figure \ref{fig:ctrdoi-20} we see the CTR improves (as in decreases) with increasing amounts of wrapping by 20ps; from unwrapped, to partially wrapped and finally
to wrapped. This is due to increased light output as seen in figure \ref{fig:lightoutput-20}. These measurements have lower individual CTR errors
than the previous 30mm measurements, likely due to a greater number of $\gamma\gamma$ events
recorded; recorded. These being namely 5000 for LSO:CeCa compared to 3400 for LYSO:Ce.
In [figure 8] \cite{r_Paganoni_Pauwels_et_al__2011} a CTR As the volume of
210ps scintillator crystal is
seen for the
$2\times2\times20$mm$^3$ LSO:CeCa scintillator crystal. We also see same in both measurements this difference is primarily due to the
difference in measurement time. The wrapped CTR
is $198\pm2$ps compared to 176$\pm$7ps for
the standard coincidence measurement given in [Table 2]\cite{uffray_Jarron_Meyer_Lecoq_2014}. For an equivalent $2\times2\times20$mm$^3$ LYSO:Ce scintillator crystal
is a CTR of 202.7$\pm$4.0ps in standard
coincidence. Compared to the values given in table \ref{tab:doictrresults-20} coincidence is observed. Therefore we see
an equivalent value for that LSO:CeCa is a superior material to that of LYSO:Ce. We also see that the
wrapped configuration.
In CTR is worse in the
wrapped DOI
measurement we see a value of 198.3$\pm$4.4ps. In timing coincidence apparatus than in the standard. This conclusion is in agreement with the 30mm
LYSO measurements
where we see values of 225.0$\pm$3.1ps for the standard coincidence to 239$\pm$4ps in the DOI coincidence apparatus.
Both measurements indicate no improvement to the CTR, within error, is expected for inclusion of confinement information.