Differences

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

--- group_10 [2018/09/13 16:07]
dombos
+++ group_10 [2018/09/13 17:06]
moylan
@@ Line 94: / Line 94: @@
 **Problem 8**
-The mass resolutions of ''stgeorge.fox'' without any modifications are given at the beginning of the previous problem.
+As stated in Problem 7, the mass resolutions of ''stgeorge.fox'' without any modifications are
-In order to have a 5% decrease in the mass resolutions, the final resolutions must be
+Mres_x = 60.123, and
-(60.123-x)/(60.123) = 0.05 -> x = 57.11685%, and (59.262-y)/(59.262) = 0.05 -> y = 56.2989%.
+Mres_y = 59.262.
+We adjusted beam parameters until we saw Mres_x and Mres_y drop to around 55.
+The beam position (offsetting the optical axis) can be changed with the ''SA'' command.
+With ''SA 0.0005 0.0;'', Mres_x = 55.18793673041390 and Mres_y = 54.57598045160019. This is close to a 5% decrease.
+With ''SA 0.0 0.0014;'', Mres_x = 55.03721889327960 and Mres_y = 54.24635345218690. This is close to a 5% decrease.
+The beam size can be changed by adjusting the first and fourth parameter of the ''SB'' command to change the x- and y-extent respectively.
+With these two parameters each changed from the default 0.0015 to 0.0017, Mres_x and Mres_y each drop to about 55. A 0.2mm increase in size measurably drops the mass resolution.
+Decreasing these parameters only increases the mass resolution. It seems the smaller the beam spot, the larger the mass resolution.
-The beam position can be changed with the ''SA'' command.

JINA-CEE ION OPTICS SUMMER SCHOOL: JIOSS 2018