-> Remake event display 6969 event 2  (flip sign toa)

  -> remake radius 90, time 90 plot with LineWidth smaller 

    Circle fit 
  "A dedicated pattern recognition program was written to find and fit multiple circles in an event.
To find circles, large clusters were down weighted. The hits within 15 pixels (in $xy$) of the chip edge were removed.
In the circle fit, the resolution in $xy$ was estimated to be about 4 pixels and in $z$ it was 1 mm."
  
  -> add explanation
    
  -> Figure 4 Plot Resolution fitted sigma xy ->   fitted sigma_xy Greek?  
     remake plot

  -> Figure 5:  vertical axis label: (sigma) -> [$\sigma$)]
     remake plot