LD 554 83 User manual

11/01-W97-Sel
Instruction sheet 554 83
Goniometer (554 83)
1 Target arm
with target holder (1a), target stage (1b
2 Sensor arm
with sensor holder (2a), sensor seat (2b)
3 Bottom guide groove
with knurled screws (3a)
4 Terminal pin connector
5 Top guide groove
1 Description
The goniometer is a self-contained unit for mounting in the X-
ray apparatus and is included in the scope of supply of the X-
ray apparatus (554 811). It is equipped with two independently
controllable stepping motors which move the sensor and target
arms. The motion is defined using the keys in the control panel
of the X-ray apparatus and initiated manually with the ADJUST
knob or automatically with the SCAN key (see instruction sheet
of the X-ray apparatus).
The target stage can accommodate e.g. the LiF crystal for
Bragg reflection (554 77), the NaCl crystal for Bragg reflection
(554 78), the aluminum scattering body from the Compton ac-
cessory X-ray (554 836) or other samples.
The entire goniometer unit can be shifted within the experiment
chamber. The length of the sensor arm is variable, so that the
angular resolution can be altered for the slit of the sensor.
Note
2 Technical data
Working principle: stepping motors for target and
sensor arms, which can be
electronically coupled
Angular resolution: 0.1°
Angular range of target: unlimited
Angular range of sensor: approx. -10° to 170°
Sensor arm:
Length of sensor arm: approx. 40-110 mm
Width of sensor slit: 1 mm
Target stage:
Sample clamping width: 3-9 mm
Area of platform: 25 mm x 28 mm
General data:
Dimensions: 13.5 cm × 22.5 cm × 12.5 cm
Weight: 3 kg
The goniometer is positioned solely by means of electric
stepper motors:
• Do not block the target arm and sensor arm of the
goniometer and do not use force to move them.

Instruction sheet 554 83 page 2/4
3 Zero position of the measuring system
Warning: Each time the zero position of the measuring system
is changed the old values of the zero position are overwritten in
the microprocessor memory by the new values
The zero position of the goniometer measuring system is deter-
mined by arm movement toward two light barriers with subse-
quent step correction. The correction values with reference to
the position of the light barriers are stored in the X-ray appara-
tus.
You can adjust the zero position of the measuring system most
precisely using the experiment “Bragg reflection”; the adjust-
ment is then with reference to the lattice planes of the
monocrystal.
Additionally required:
1 End-window counter for a, b, γ radiation
and x-rays 559 01
1 NaCl crystal for Bragg reflection 554 78
(in scope of supply of 554 811)
- Press the ZERO key to return the target and sensor arms to
the current zero position.
- Mount the NaCl crystal and the end-window counter (see
below).
- In coupled scanning mode, set the target to about 7.2° using
the ADJUST knob.
- Set the tube high voltage U= 35.0 kV and emission current
I= 1.00 mA and switch on the tube high voltage with
HV ON/OFF.
- Switch between sensor and target scanning modes and
locate the maximum counting rate for the first reflection
maximum of the NaCl monocrystal under manual control .
- In coupled scanning mode, move the target back by 7.2°
(even if this takes you into the negative range!).
- Save the positions of the target and the sensor as the “zero
position of the measuring system” by pressing TARGET,
COUPLED and β LIMITS simultaneously.
- To verify your adjustments, assume the angle 7.2° in
coupled scanning mode and check the maximum counting
rate.
4 Mounting and demounting
Mounting:
- Mount the target and sensor holders, if this has not already
been done.
- Lay the ribbon cable of the X-ray apparatus out flat and to
the right behind the bottom guide rod in the experiment
chamber.
- Screw off the knurled screws of the bottom guide groove.
- Set the top guide groove over the top guide rod.
- Pivot the bottom section of the goniometer onto the bottom
guide rail of the X-ray apparatus, raise the goniometer and
place it in the assembly so that the bottom guide rod slides
into the bottom guide groove of the goniometer.
- Slide the goniometer in the experiment chamber to the left
and plug the ribbon cable into the connector of the goniome-
ter (check to make sure that the polarity-reversal protectors
line up).
- Slide the goniometer to the desired distance from the colli-
mator, insert the knurled screws of the bottom guide slot and
tighten them.
- Mount the sensor.
Demounting:
- Remove the sensor from its seat.
- Screw off the knurled screws of the bottom guide groove of
the goniometer.
- Slide the goniometer in the experiment chamber to the left
and unplug the ribbon cable from the connector on the go-
niometer.
- Manually steer the sensor arm of the goniometer to the 0°
position.
- Lift the goniometer until it touches the top guide rod, lift the
bottom section of the goniometer forward and lower it until
the upper section of the goniometer can also be lifted for-
ward.

page 3/4 Instruction sheet 554 83
5 Mounting/ demounting the sensor holder
Mounting:
- Remove the target holder.
- Loosen the knurled screw on the sensor arm.
- First insert the bottom guide rail of the sensor holder in the
bottom groove of the sensor arm and then insert the top
guide rail into the top groove until it snaps in.
- Set the desired distance between the target and the sensor
and then fix the sensor holder in position with the corre-
sponding knurled screw.
Demounting:
- Remove the sensor.
- Remove the target holder.
- Loosen the knurled screw on the sensor arm.
- Lift the top guide rail of the sensor holder out of the top groo-
ve of the sensor arm and lower the sensor holder.
Adjusting the sensor arm:
- Loosen the knurled screw on the sensor arm.
- Set the desired distance between the target and the sensor
and then fix the sensor holder in position with the
corresponding knurled screw.
6 Inserting a sensor
- Slide the goniometer to the left in the experiment chamber
as necessary.
- Loosen the knurled screw at the sensor seat.
- Remove the cover cap from the end-window counter, care-
fully insert the counter in the sensor seat from the rear as far
as it will go and then tighten the knurled screw.
- Press the SENSOR key and use the ADJUST knob to check
that the sensor holder can move freely in the angular range
you wish to investigate.
When using the internal rate meter:
- Connect the lead of the counter tube to the socket marked
GM TUBE in the experiment chamber.
When using an external counter:
- Connect the counter tube lead to the socket marked HV
OUT in the experiment chamber and connect the socket HV
IN on the connector panel of the X-ray apparatus to the ex-
ternal counter.

Instruction sheet 554 83 page 4/4
LEYBOLD DIDACTIC GMBH .Leyboldstrasse 1 .D-50354 Hürth .Phone [phone] .Fax [phone] .e-mail: [e-mail]
by Leybold Didactic GmbH Printed in the Federal Republic of Germany
Technical alterations reserved
7 Mounting/ demounting the target holder
Mounting:
- Mount the goniometer and position the target arm of the go-
niometer horizontally with the ZERO key (the V-shaped
groove in the bushing of the target arm must be vertical).
- Insert the axle of the target holder into the bushing of the tar-
get arm so that the cotter pin of the axle slides into the V-
shaped groove of the bushing.
- Tighten the union nut of the target holder finger-tight.
Demounting:
- First remove the target, e.g. monocrystal, if one has been
set up (see below).
- Loosen the union nut of the target holder.
- Pull the axle of the target holder forward out of the bushing
of the target arm.
8 Mounting/ demounting the target stage
Mounting:
- Loosen the knurled screw on the target stage.
- Insert the plastic guide in the groove of the target holder
from below and raise the target stage as far as it will go.
- Tighten the knurled screw finger-tight.
Demounting:
- First remove the target (see section below).
- Loosen the knurled screw on the target stage and pull the
target stage downward out of the groove of the target holder.
9 Setting up a target
- Position the target and sensor arms of the goniometer hori-
zontally using the ZERO key.
- Loosen the knurled screw of the target stage and lower the
platform slightly.
- Lay the target (e.g. NaCl crystal or aluminum scattering
body) flat on the target stage and push it backwards against
the back stop.
- Raise the target stage with the target up against the stop
edge and tighten the knurled screw finger-tight.
- Carefully check that the target is held firmly.