Skip to content

Rhs chopper #1610

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
ggoneiESS wants to merge 3 commits into
base: main
Choose a base branch
from
Open

Rhs chopper #1610

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
7499bc9
add additional field
ggoneiESS Jan 8, 2026
d4aa983
undo change
ggoneiESS Jan 8, 2026
2978abf
add additional field
ggoneiESS Jan 8, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 20 additions & 9 deletions base_classes/NXdisk_chopper.nxdl.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,9 +45,23 @@
We refer to this below as the "top-dead-center signal".

Angles and positive rotation speeds are measured in an anticlockwise
direction when facing away from the source.
direction when facing away from the source unless otherwise specified in the `handedness` field.
</doc>

<field name="handedness">
<doc>
Direction of measurement for rotation and positions in the disk-chopper.
Left is the default for historical reasons and implies positive rotation and angles in an anticlockwise
direciton when facing away from the source.
Right matches the default NeXus coordinate system and implies positive rotation and angles in an anticlockwise
direction when looking towards the source - positive rotation matches the positive roll of the system.
Only one from the enumerated list (match text exactly).
</doc>
<enumeration>
<item value="Left" />
<item value="Right" />
</enumeration>
</field>
<field name="type">
<doc>Type of the disk-chopper: only one from the enumerated list (match text exactly)</doc>
<enumeration>
Expand All @@ -58,8 +72,7 @@
</field>
<field name="rotation_speed" type="NX_FLOAT" units="NX_FREQUENCY">
<doc>
Chopper rotation speed. Positive for anticlockwise rotation when
facing away from the source, negative otherwise.
Chopper rotation speed.
</doc>
</field>
<field name="slits" type="NX_INT">
Expand All @@ -74,8 +87,7 @@
<field name="slit_edges" type="NX_FLOAT" units="NX_ANGLE">
<doc>
Angle of each edge of every slit from the position of the
top-dead-center timestamp sensor, anticlockwise when facing
away from the source.
top-dead-center timestamp sensor.
The first edge must be the opening edge of a slit, thus the last edge
may have an angle greater than 360 degrees.
</doc>
Expand All @@ -93,8 +105,7 @@
<field name="beam_position" type="NX_FLOAT" units="NX_ANGLE">
<doc>
Angular separation of the center of the beam and the
top-dead-center timestamp sensor, anticlockwise when facing
away from the source.
top-dead-center timestamp sensor.
</doc>
</field>
<field name="radius" type="NX_FLOAT" units="NX_LENGTH">
Expand Down Expand Up @@ -140,9 +151,9 @@
the source. The reference point in the x and y axis is the point on this surface which is the
centre of the axle which the disk is spinning around. The reference plane is orthogonal to
the z axis and its position is the reference point on that axis.

Note: This reference point in almost all practical cases is not where the beam passes though.

.. image:: disk_chopper/disk_chopper.png
:width: 40%
</doc>
Expand Down