There are many reasons why eventualy the detector has no photons to detect. If you experience this, check:

  • storage ring current has to be >1mA: no current means no electrons which obviously leads to no photons for beamlines
  • Front End has to be open: check in idappli and open it
  • check the undulators' gaps [in iddapli Commands/ID control]. ;-) It is a joke, you are on a bending magnet beamline: no possibility to modify the gap between north and south poles of the electromagnet without a hammer or so...
  • safety shutter has to be open: check its state in vacuum appli or in BsxCuBE, you can open/close it manually using these applications or directly in spec EXP session by shopen/shclose command. Hint: one can open it only if the Experimental hutch was interlocked;
  • small exposure (fast) shutter has to be open during data collection: check its state in BsxCuBE (it should open automatically during data collection), you can open/close it manually using BsxCuBE (in beamline tab) or directly in spec exp by msopen/msclose commands. Hint: eventualy this shutter (=rotating hole) can lost its open/close positions (0°/90°) and has to be realigned (see fast shutter realignment);
  • all vacuum valves have to be open: green in vacuum appli (if not: click on its picture and "open", to close the window click on "dismiss");
  • all fluorescent screens have to be out of beam: check on http://ld292:8066/ (cameras in Optics hutch) and http://bm29video1/  (cameras in Experimental hutch) if it is the case. If you see some intensity on any of them, take it out: in Spec OH tape "wbout" (fluo screen after Primary slits), "monoout" (fluo screen after multilayer monochromator), "mirrout" (fluo screen after toroidal mirror) and "endout" (fluo screen after secondary slits number 2) for Optics hutch, in Spec EXP "yagout", "diodeout", "yag1out", "yag2out" and "yagftout" for fluo screens in the Experimental hutch respectively;
  • guillotine (=led plate between detector and flight tube) is not open: check on Big brother video camera (or through the window in the Experimental hutch) if open when collecting. If not you can open/close it directly from BsxCuBE (in Beamline tab) or in spec EXP: "guillopen" or "guillclose".