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14. If both 137Cs peaks are visible, but are closer together than wanted, increase the HV and go back to step 4.
15. If the HV is at the highest HV recommended by the detector manufacturer (or if it is higher than you are
comfortable with or is obviously distorting the spectrum), leave the HV where it is, increase the overall gain
and go back to step 4.
16. When the two peaks are in their optimal locations, uncheck the “Allow Edit” box.
17. Click the “Full Screen” button on the button panel to close the Hardware Settings panel and restore the
spectrum to the largest possible viewable area.
Once all the hardware settings are finalized, an energy calibration can be performed.
Performing an Energy Calibration
Prerequisites
This procedure assumes that detector is attached to the URSA-II, the URSA-II is switched on, the URSA-II MCA
software has been successfully started, a radioactive source of known isotopic composition is on the detector,
and URSA-II hardware settings have been set appropriately. Note: The Energy Calibration is unique to each
URSAII/ detector combination. The specific energy calibration settings are loaded when a specific detector is
selected. If you intend to use the same detector with different energy calibration values (e.g., to account for
differing source geometries), you can define separate detectors with different descriptions.
Discussion
URSA-II MCA uses a linear interpolation between energy calibration points. More sophisticated modeling was
not implemented because of the wide range of characteristics in the detectors supported by the URSA-II, which
make it impossible to accurately model for energy response. It was also determined that there were certain
