Differences

This shows you the differences between two versions of the page.

--- beam_profile_monitors [2012/03/23 12:33] – created jacobs
+++ beam_profile_monitors [2026/06/25 16:12] (current) – external edit 127.0.0.1
@@ Line 5: / Line 5: @@
 The system is normally ready to use at all times.  The operator selects the desired BPM by pushing the appropriate button on the brown control panel (HE, LE, SW, etc.).  The operator may set the sensitivity by selecting between x1 and x10 on the control panel.  No other settings on the control panel should be used.  The profile display can be adjusted further by changing the VOLTS/DIV scale on the occiloscope.
-The BPM system displays the Y axis profile on the left half of the oscilloscope and the X axis profile on the right half.  The center point of each axis is indicated by a bright fiducial mark on the trace line.  These marks do not move.
+The BPM system displays the Y axis profile on the left half of the oscilloscope and the X axis profile on the right half.  The center point of each axis is indicated by a bright fiducial mark on the trace line.  These marks do not change.
+The profile for a given axis will appear as a peak.  The peak will be sharp and tall if the beam is tightly focussed.  The peak will be broad and flat if the beam is broadly focussed.  If the beam is centered the fiducial mark will be located at the top of the peak.  If the beam is off center the fiducial mark will be off to one side of the peak.
+The BPM is protected by a 1" collimator.  If beam is striking the collimator the oscilloscope trace will be highly distorted.
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