Boot control pc.
Login as guest and choose the desktop you prefer.
Open a terminal (click on symbol with shell).
Start spec respectively twoc by typingtwoc.
Configuration of standard-parameters as printer, terminal, working directory etc.:
startupasks for all parameters. In most cases the default values will be fine. You just have to choose your working directory and destination file for the data. Normally we use UserMonthYear (Your name and aktual date) as working directory.
As the Scans are stored in one file it might be good using different destination files for different samples. The output destination is changed via the comandnewfilename(Example: newfile sample1).
setplotsets up the parameters for plotting on the screen. Normally these need not to be changed.
AutoRaise:
AutoRaise brings the plotting window to the front every time a point is added.
raise_onactivates AutoRaise.
raise_offshuts AutoRaise down.
Motor control:
mvmotorname positionmoves motor motorname to the absolut position position.
Example: mv th 1.0 (moves th to 1.0 degree)
mvrmotorname relativpositionmoves motor motorname relativ from the actual position by relativposition.
Example: mvr th 1.0 (moves th by +1.0 degree from the actual position)
joymotorname steplengthmoves motor motornameeach time pressing k by steplength in positiv direction and by pressinglin negativ direction.
Pressingnchanges the steplength.
Example: joy th 0.1
ctwmotorname steplength time
moves motor motornameby typing+or-by stepplength in positiv or negative direction, respectivly by counting time seconds.
Example: ctw th 0.1 1
antth_position th_positionmoves tth and th simultanously.
Example: an 1.0 0.5 (moves tth to 1 and th to .5 degree)
ascanmotorname start end steps timescans motor motorname starting from the absolute value start to the absolute value end by counting for time seconds and stepping points steps.
Example: ascan th 1.0 2.0 21 1 (Scans th from 1.0 to 2.0 Grad, 21 points, counting for 1 s at each point)
a2scanmotorname1 start1 end2 motorname2 start2 end2 steps timesimilar toascanbut for scanning two motors.
Example: ascan th 1.0 2.0 21 1 (Scans th from 1.0 to 2.0 Grad, 21 points, counting for 1 s at each point)
dscanmotorname start end steps timescans motor motorname starting from the relative value start to the relative value end by counting for time seconds and stepping points steps.
Example: dscan th -0.5 0.5 21 1 (Scans th between -0.5 and +0.5 degree with respect to the actual position by 21 steps counting for 1 s at each point)
timescantime (default time =1sec)
Example: timescan 1 (Each second one data point is collected, finish with STRG C).
STRG Cwill interupt scans or motor motions.
resumeorscan_oncontinues an interupted scan.
washows the position of all motors.
wmmotornameshows the position of motor motorname.
setmotorname valuesets the actual motor position of motor motorname to value.
set_dialmotorname valuesets the actual motor position of motor motorname to value internal in the HUBER-controler.
onsimswitches to simulation modus. This helps for the testing of macros.
offsimswitches off simulation modus.
quitshuts down twoc.
To define the resolution three slits are used. The incoming beam is defined by two slits (slit1 and slit2) with a distance of 2 m.
The scattered beam is difined in front of the detector (slit3).
slit1 width Sets S1 to width mm.
slit2 width Sets S2 to width mm.
slit3 width Sets S3 to width mm.
slit width Sets S1 and S2 to width mm.
show_slitshows the position of the slits.
write_slitwrites the position of the slits to the output file.
cplotscannrplotts the scan with number scannr to the desktop.
cplotscannr_1-scannr_2plotts al scans between scannr_1 and scannr_2 to the desktop.
cplotscannr_1,scannr_2plotts the scans with number scannr_1 and scannr_n to the desktop.
pplotscannrplotts the scan with number scannr to the printer.
pplotscannr_1-scannr_2plotts al scans between scannr_1 and scannr_2 to the printer.
pplotscannr_1,scannr_2plotts the scans with number scannr_1 and scannr_n to the printer.
cpsetupallows setting the parameters for plotting.
linplotfilename scannr x_Achstextplotts the scan with number scannr normalised to the counting time with a linear scale to the desktop.
logplotfilename scannr x_Achstextplotts the scan with number scannr normalised to the counting time with a logaritmic scale to the desktop.
linplotfilename scannr x_Achstextplotts the scan with number scannr normalised to the counting time with a linear scale to the printer.
logplotfilename scannr x_Achstextplotts the scan with number scannr normalised to the counting time with a logaritmic scale to the printer.
nicht akzeptiert (siehe Beispiel).
Neutrons coming from the polariser or analiser are defined as down neutrons.
pol onsets up the polarisation mode and moves the polarizer into the beam.
pol offshuts down the polarisation mode and moves the polarizer out of the beam.ana onsets up the analysation mode and moves the analizer into the beam.
ana offshuts down the analysation mode and moves the analizer out of the beam.
Spinflipper...
The flipping coils have to be moved in by hand.
init_flipinitializes both flippers.
scan_flipFLIPPER COIL start-curr stop-curr inteval time scans the current in one flipper coil.
Parameters:
FLIPPER={f, front, b, back}
COIL={f, flip, c, compensation},
0 A <=start-curr<= 2 A
0A <=stop-curr<= 2 A
Example: scan_flip f f 0 2 20 1scans the flipping coil of the fron flipper with currents from 0 - 2 A in 20 steps for 1 s per step.
set_flip FLIPPER COIL valuesets the current for the specified coil.
Mesurment without analysation:
spin uswitches on the flipping coil (front flipper).
spin dswitches off the flipping coil (front flipper).
spin uuswitches on both flipping coil.
spin udswitches on the fron flipper and off the back flipper.
spin duswitches off the fron flipper and on the back flipper.
spin ddswitches off both flipping coil.
Due to the thermal expansion or contraction of the cryostat by changing temperature the alignment of the sample has to checked each time the temperature is changed.
Mitshow_tempwshows the setpoint and the sample temperature.
set_temptemperaturesets the setpoint to temperature.
heat_rangenumbersets the maximum heating power. Thenumberhas to be between 0 and 5 (0=OFF,1=11mW,2=112mW,3=1.1W,4=11Wund5=89W)
heat_rangewithout number shows the actual maximum heating power.
wait_tempmakes twoc to wait until the sample has reached the setpoint temperature.
threshold_temp [deltatemp] [time] sets a temperature range in Kelvin. The temparature is assumed to be stable if it remaines within the temperature range deltatemp for time seconds.
write_tempwrites the setpoint and the sample temperature to the output file.
Temperatur 'scannen'...
scan_temp starttemp finishtemp intervall time [sleeptime] allows to measure the intensity depending on the temperature. gx will be realigned.
psd onswitches on the psd and the pencil detector off.
psd offswitches off the psd and the pencil detector on.
detector inmoves the pencil detector in the beam and switches from the psd to the pencil detector.
detector outmoves the pencil detector out of the beam and switches from the pencil detector to the psd.
After using the comand detector in or out you should realign tth to make shure that there is no offset between the two detectors.
psd_dimnumbersets the dimension of the psd. 1 means sumation over columns. 2 means the hole picture will be saved.
All data are directly mirrowed to the pc left of the control pc. You must not use the control pc for data treatment as this might lead to instabilities in the system. To extract the specular reflectivity for each scan from the spec file run the perl script split.pl. This will produce datafiles with the scan number appended. The files contain the scanned motorposition and intensities in ASCII format.
For visualisation of the psd data you may use the matlabscript psd. This script is windows based and rather self explaining.
© 31.3.2004 by Max Wolff.
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