Changing the Camera length of the SAXS setup at 12IDC:

• Turn of turbo pump
• Open bleed valve slowly and wait till vacuum pipe is up to atmospheric pressure
• Disconnect flexible hose from vacuum pipe.
• Move MARCCD camera back and put protection cover on the front window of the camera
• Disconnect hose clamp at front part of vacuum pipe.
• Disconnect front nozzle from vacuum pipe
• Disconnect vacuum feed through connecter for beam stop.
• Lift of the vacuum pipe from the table and lay it on the floor. Do not touch the vacuum window of the vacuum pipe. This can lead to damage and mal function of the window. If the length of the pipe is more than meters definitely use the hoist. ( see hoist training).
• To lengthen the vacuum pipe to the required length needed add remove pipe sections as needed. Always 3 clamps and a gasket are needed for each connection. The vacuum connection at the pipe containing the beam stop and the window can only be disconnected while the pipe is standing up vertically to avoid the gasket shearing of the beam stop.
• After reassembling the pipe to the desired length put vacuum pipe back into the V shaped holders on the table.
• Reconnect pumping hose, vacuum feed through connecter for beam stop .
• Reconnect hose clamp for vacuum pipe.
• Turn X-ray beam on.
• On PC switch sensitivity of amplifier 2 ( scaler 2 for photo diode beam stop ) 10^-9 A/V.
• Move table (Atomic physics table) horizontally and vertically by 0.05 inch steps and observe the scaler value. Move onto the direction where the scaler is increasing.( hunting for the beam). he intensity of the photo diode should be at least 200 10-6 A.
• Beam of
• After the intensity is maximized put front nozzle back onto the pipe turn on vacuum pump and attach burn paper on the window of the nozzle.
• Beam on for about 10 seconds.
• Burn mark should indicate the beam to go through the center window of the nozzle. Otherwise adjust the holder for the upstream part of the vacuum pipe until the beam is centered through the window.
• Maximize the beam stop intensity again by moving the table again. The smallest step size to be used shall not be smaller than 0.002 inch.
• When the beam stop is aligned remove cover from MARCCD and take a test exposure. If exposed scattering pattern looks symmetric, changeover was successful. Otherwise further alignment has to be done. Finer alignment of beam stop or alignment of cleanup slits.
• Now calibration can be done with proper calibration sample like Silver Behenate and Lupolen standard (PE).