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Getting Started

We have new BLU-ICE but you can only run it from graphics1, the machine on the right, although the control program itself is mostly running on bl831.  You just can't use the sun machine on the left for it anymore.  I don't know what the command is to start it anymore.  It used to be "session" in the session window and then "ice" in the ice window.  You could also try the usual suspects: "go", "start", or a new one, "nuke" if the others don't work.  Nuke, I believe, wipes out all the old processes if things have locked up and then restarts everything.  Note that ICE uses adxv for display so don't close that down (it does it in autoload mode to follow the frames), but it is EXCEPTIONALLY SLOW TO LOAD THE MOST RECENT FRAME.  This is a known problem with NFS or something.  I like to have a separate instance of adxv running in another window (type "adxv" to start it) and that one you can manually load any frame you like faster.

The Hutch

To open the hutch:

Press the photons off button to stop the beam.

Press the Door open button, then hold the door open button down while opening the door.  Good, safe, yet simple.

 Other Tips

Want to know when your data set will be done?  type "eta.com" and the script will look at the current runs goals, the time stamps on frames being produced and give you estimates of when it will finish updated every frame or so.

The spot shape on detector options on BLU-ICE hutch tab don't currently work.  Instead, type "divergence.com" to see current values (usually 2.0 0.5).  Type "divergence.com 0.5 0.5" to get smaller slits for example.

Two-theta works.  Enter the value you want in the two-theta window on the BLU-ICE hutch tab.  As usual, press "START" to apply the changes you've entered and actually move the detector to that two theta value.  Note two things: 20degrees is a lot as you'll see if you ever lift it 20, especially if you are far back.  Be very careful using 2theta when you are close in.  It should be OK, but watch out for detector/apparatus potential collisions.  And third of two, note that the resolution predictor won't work at the two theta angle.  You can estimate the beam center position (tan(2theta)*detector distance) and subtract this off of the y value in adxv "settings" to get an approximation of the beam center.  If you have close spots an even better idea or in addition, is to take a direct beam.

Direct beam: Put in all the foils (Se,Cu,Al), set exposure time to 0.1 sec, use an energy effectively absorbed by the foils (1.1 A (~11200) should be OK)

Every few hours you may want to check and tune up the beam alignment.  You can do this by typing tuneup.com in a window or use the "optimize beam" button in the hutch tab of BLU-ICE.  Either one will move your crystal safely out of the way while it does its thing, generate a few graphs, and bring your crystal back when it's done.  Note that when it reports beam intensity as a percentage of max, the max possible may not take into account slit adjustments or other sundry things you may have on.

Given the camera view is down the axis of the beam...i.e. you see what the photons see, then with phi=0 you can use the Y-axis to move the crystal in and out of the focus plane. 

As of March, 2002 there is a swing out shelf in the hutch that swings under the crystal or stows under the platform.  It has a tacky (literally) surface which makes it kind of exciting (read treacherous) to get very full wide LN2 dewars off of it.  Turns out there's a switch that senses the tray position, so you can't drive the motors while the shelf is out.  (i.e. Detector could collide with it, collimator set up could collide with it...)  So be sure the shelf is fully returned to its stowed position and tray tables and seat backs are in their upright position before you attempt take-off.

If the phone rings in the middle of your night shift, and you groggily answer it, "line 8.3.1, hello?" and a voice shouts back "8.3.1 WHAT THE HELL ARE YOU DOING WITH THE SHUTTERS?!?!", it's probably just Luke helping keep you awake.  I found out that this works quite well.

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