Tecnai on-line help manual -- Options - UT Southwestern

<strong>Tecnai</strong> on-line help Options 95Options Software version 2buttons work such that the selection for the other zone axes (that is, secondary for the primary-axis spinbutton and vice versa) is always skipped. It is thus not possible to have the primary and secondary zoneaxes on the same zone memory. If you want to use zone memory 2 as the primary axis, while it currentlyis at the secondary axis, and another as the secondary, then first change the secondary zone from 2 toanother value and then the primary axis can be changed to select 2.Zone axisThe two zone axes used for the indexing are displayed in the edit controls just below the “Calculator”buttons. The zone index can be changed by clicking on the required index in the list underneath or bytyping in the index.. The special keyboard keys are used to enter negative values.Zone axes listThe zone axis lists contain the possible indices of the zone axes, as determined via the zone axisCalculator. In the current version of the software, there is no particular sequence in the lists and allentries will be found to occur more than once. To determine if a second axis is compatible with a solutionafter a first axis has been defined (click in the primary zone axis list), click somewhere in the secondaryaxis zone list, then use the up or down arrows to change the selection. The 'Degrees between zone'value will be updated after each change. when the value matches that measured with the stage, thematch is correct.View patternWhen the View pattern button is pressed, the diffraction display on the right will show the diffractionpattern for the primary of secondary zone axis. If the camera constant is on manual scaling, the valuewill be set to a camera constant of 10 to allow viewing of the pattern.Diffraction patternThe diffraction pattern is displayed to the right. This pattern either corresponds to the pattern determinedby the current orientation of the Lab grid or to the pattern of the zone axis selected for which the 'Viewpattern' button was pressed. By viewing the diffraction pattern it is, for example, possible to compare thedisplayed pattern with that on the microscope. In this it is possible to distinguish between solutions thatare mirror images of each other.Degrees between zonesAfter 'Degrees between zones' the difference in angle between the two zones used for two-zoneindexing are displayed. These tilts are calculated when the selection in the edit controls is changed (bymake a change in the selection in one of the lists)..Degrees between stageAfter 'Degrees between stage' the difference in angle between the stage tilts for the two zones used fortwo-zone indexing are displayed. These tilts are read automatically from the microscope.SuggestionAfter two zone axes have been defined through the calculator, the software will determine a matchbetween zone axes, based on the angle measured with the stage. The match is usually only one of a setof possible permutations. For example, the match suggested with 00-1 and 02-1 is equally valid to thematch selected (of 100 and 102).IndexPressing Index exits from the Two-zone indexing dialog, while changing the orientation as defined by theselection for the two zone axes.Note: The position of the primary zone axis is assumed to be absolute (so it is made to coincide exactlywith the stage position measured for it) and any difference between the calculated and measured angles