<DIV><FONT face=arial>Hi all,</FONT></DIV>  <DIV><FONT face=arial></FONT>&nbsp;</DIV>  <DIV><FONT face=arial>I am simulating Tc source for&nbsp;SPECT system and I would like to model an&nbsp;energy window. Is it correct to use these lines of command:</FONT></DIV>  <DIV><FONT face=arial></FONT>&nbsp;</DIV><FONT size=2>  <DIV><FONT face=arial>/gate/digitizer/Singles/insert thresholder</FONT></DIV>  <DIV><FONT face=arial>/gate/digitizer/Singles/thresholder/setThreshold 126. keV</FONT></DIV>  <DIV><FONT face=arial>/gate/digitizer/Singles/insert upholder</FONT></DIV>  <DIV><FONT face=arial>/gate/digitizer/Singles/upholder/setUphold 154. keV</FONT></DIV></FONT>  <DIV><FONT face=arial></FONT>&nbsp;</DIV>  <DIV><FONT face=arial>&nbsp;or they are only used&nbsp;to speed up the simulation?</FONT></DIV>  <DIV><FONT face=arial></FONT>&nbsp;</DIV>  <DIV><FONT face=arial>Thanks in advance.</FONT></DIV>  <DIV><FONT face=arial>Margaret</FONT></DIV>  <DIV><FONT
 face=arial></FONT>&nbsp;</DIV>  <DIV><FONT face=arial></FONT>&nbsp;</DIV><p>&#32;
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