G1 Hardware

Quantum 1 Detector

The Quantum 1 CCD detector has a pixel size of 70.7 mm and a total array of 1152 x 1152  pixels. the active area is 3 mm behind the front plate of the detector.

To start the Quantum 1 detector you have to start it with typing 'start_CCD' from a g1hutch terminal window (the prompt says g1hutch, NOT g1), followed by 'start_rspec', to establish the communication with the shutter and the counters. A bunch of windows should pop up and to take an image, choose in the window called only ADX setup followed by snapshot. Give the directory where the file should be stored, the filename, sample-to-detector distance, and the exposure time. Start each time with a short exposure time after you opened the garage door to make sure the beamstop is in place.

The exposed images are automatically corrected for  intensity and distortion.  If there is an existing "dark" image with the the current exposure time, images are also background-subtracted.  If not, click the "collect new dark current" radio button at the bottom of the snapshot window before snapping the image. 

Calibration for online estimates of d spacings:

• take an image of one of the Silver behenate samples in the top drawer of the black rack in front of the slits.

• In the window Adxv Control (that one where you set the color scale) select Edit>Settings.

• Click Pick Center and click roughly on the position of the direct beam.

• now select Behenate and you should see some dashed rings on the image.

• type in pixel size (0.707 mm) and your current Wavelength.

• Now adjust the Distance and the Beam Center values so that the rings from the image and the dashed rings overlap.

• Press Fix Settings to store these values for your current run.

• For notes on SAXS Calibrants see also here.