deletions | additions       diff --git a/subsection_Gas_cell_functionality_The__.tex b/subsection_Gas_cell_functionality_The__.tex  index e84d675..5511d21 100644  --- a/subsection_Gas_cell_functionality_The__.tex  +++ b/subsection_Gas_cell_functionality_The__.tex 
...
\subsection{Gas cell functionality}  The gas cell has been thoroughly tested with multiple elements. Within a wide range of elements, we saw as cell efficiency -- combined stopping and extraction efficiency -- of 10\%$\sim$30\%. These efficiencies were determined by monitoring the inelastic scattering at the target, normalized to the rate of ions entering the gas cell as determined by an array of PIN diodes temporarily inserted between GARIS-II and the gas cell.  Figure~\ref{figStopExtractEff} shows the measured gas cell efficiencies for $^{205}$Fr ($T_{1/2}$=3.8~s), $^{213, 215}$Ac ($T_{1/2}$=738~ms and 170~ms), $^{216}$Th ($T_{1/2}$=26~ms), and $^{217}$Pa ($T_{1_2}$=3.5~ms) as functions of the degrader thickness. In the case of the highly chemically active element At, a combined stopping and extraction efficiency of $\sim$3\% was seen for $^{201}$At$^+$, although no measurement was made as a function of degrader thickness, and the chemically active nature of At may have resulted in numerous molecular sidebands that were not observed. The gas cell was designed to allow for cryogenic operation. Cryogenic operation provides two benefits: the gas density (and thereby stopping power) increases for a given pressure, and contaminant molecules freeze out of the gas. The gas cell has been tested online and offline down to $\sim$50~K. At reduced temperature we did observe a significant decrease in stable molecules extracted from the gas cell. However, no increase in overall efficiency was observed with cryogenic operation, indicating that $\sim$100\% of incoming beam is stopped in the gas cell even at room temperature.