The NCD pages are currently being regularly updated.....

• General beamline applications
• SPEC sessions
• Managing your data
• Troubleshooting

General beamline applications

Searching the hutch

Open the Front End 

SPEC sessions

The whole beamline - the optics part and both the experimental stations - is controlled and operated using the SPEC software running on the bm16ctrl machine (industrial PC with Linux operating system). Users access bm16ctrl through the X-terminals Ybm16ctrl (left one) or Xbm16ctrl (right one) in the control Hutch or XPicasso inside the Experimental Hutch.

To fully operate the NCD station, it is necessary to have the three SPEC sessions - NCD, OPTICS and SLITS - open.  Each session can be opened by clicking the appropriate icon on the bm16ctrl desktop.  Once already running, a SPEC session can not be launched again. Hence, in the case you click on either NCD/OPTICS/SLITS icon and you notice the application window briefly appearing but immediately closing, it means the session is already open (the window is either minimized or open on another desk or terminal).  

To operate the station, NCD experimentalists will only use the NCD spec session (purple background color window). Although not used, the OPTICS and SLITS sessions (dark-blue and green background color windows, respectively) must be open anyway.

The NCD session allows the control of all the SAXS/WAXS related motors, counters and sample environments. Commands are passed using an approprite spec syntaxe. 

Most common SPEC commands are :

Shutters

shopen/shclose  open/close safety shutter

opiom_shutopen/opiom_shutclose open/close fast shutter

opiom_shutstate display actual status of the fast shutter  

Moving/scanning

wa display all motors position (displayed units are either mm or degrees)

wm motname display position and soft limits for motor motname

umv motname xx  move motor motname to absolute position xx

umvr motname xx  move motor motname by xx relative to the current position

ascan motname mot_start mot_end npoints tim scan motname from mot_start to mot_end in npoint steps. The aquisition is tim in seconds 

dscan motname mot_low mot_up npoints tim scan motname from actual position-mot_low to actual position+mot_up in npoint steps. The aquisition is tim in seconds. At the end of the scan, the motor comes back to the inital value

plotselect [ count_name ] select the online displayed counter during a scan  

For users, motname of interest are detY detZ s2y s2z cwaxs  

Counting 

ct t  perform a t seconds data aquistion and display the value of all active counters

For users, counters of interest are Io (ion chamber value before the sample), dBs (pin diode value at beam stop) and of course the  MARCCD(SAXS) and PrincetonCCD(WAXS) 2D detectors.  

MARCCD(SAXS) and PrincetonCCD(WAXS) detectors are controlled by a series of similar commands.  

mccdmenu opens a menu with all parmeters settings related to the MARCDD

mccdon/mccdoff activate/desactivate the MARCCD detector (SAXS)

ccdmenu similar to mccdmenu but for the Princeton CCD

ccdon/ccdoff activate/desactivate the Princeton CCD detector (WAXS)

If a 2D detector is desactivated, it will not be integrated during a ct command

MAR CCD specific commands

mccdmenu launches an interactive menu to set up all the MARCDD related parameters (save or not a data aquisition, assign filename and directory,.... ). Drawback is that it cannot fit in a macro. Additional bm16 specific macros have been written to this purpose 

In the following, [] means an optional command. If not given, the user is prompted for an answer

mardir [ path ] assign directory where to save the next saved data aquisitions (generally path is external/bm16xx/data[/your_sub_dir])

marname [ filename ] [ num (default=1) ] assign the name and the number of the next saved file

marsave [ 0/1 ] not save(0) or save (1) the next data aquisition

marwas display the last saved data aquisition

marnext display the next saved data aquisition

Princeton CCD specific commands

princedir princename princewas princenext have the same meaning as the mar equivalent described above

Generate a log file

In NCD session, there's the option to creat a so called "log" file in which sensitive information is stored (saved filename with correpsonfing values of monitors, temperature, motors positions,...)

ncdlog [filename] assign the name to the log file 

ncdlogoff/ncdlogon disable/enable storage in the log file 

Managing your data

For each officially scheduled experiment, an account - whose name matches with the proposal number -  is created on the ESRF central computing server NICE. This account serves as the unique storage location of your data.

Linux operated computer (bm16ctrl, bm16process1, bm16process2)

You can acces your dedicated account from all the LINUX operated machines located in the BM16 control room. Once logged in one of the above computers, you have to open a new window. At this point, you are in the /users/opd16 directory (type pwd to check out). To move to your directory, type cd external/bm16xx/data (here bm16xx corresponds to your experiment number). Within this directory, you are free to organize your own data storage archictecture (e.g. create new subdirectories with the mkdir command). If you want to see the content of the directory, type ls -lrt  (the -lrt option is to have a full display of the files in chronological order of creation). The ls -lrt *.mccd command will only display files with .mccd extension. 

Windows XP operated PC (bm16princ)

Your account directory is accessible as well from the PC in the control hutch.

Analysing your data

Files produced by the Mar (.mccd extension) and the Princeton (.edf extension) CCD detectors are both readable using the Fit2d software. Fit2d  is a general purpose and specialist 1 and 2 dimensional data analysis program developped at ESRF. It is available free of charge for academic users.

Fit2d is installed on bm16process1 and bm16process2 and can be started from your data directory by typing fit2d. Fit2d runs as well on the WindowsXP PC, click in the appropriate icon to start it. 

Fit2d is essentially used to convert the (generally binary) 2D data files to 2 columns  ASCII files (Intensity vs. Q). This tranformation results from a radial integration of the 2D image. Some input parameters are required for an appropriate radial transofrmation, ask your local contact.

Some utilites have been written to allow a quick processing of a series of 2D images (batch mode running of Fit2d).