spec - Local Sector 7 web page

Type a ˆC to abort counting. The macro show_cnts will display the current scalercontents. The uct macro will update the screen with the current scaler contents duringthe counting period.ScansScans in spec are built of macros. Many different standard scans are available.Absolute-position motor scans such as ascan , a2scan and a3scan move one, two orthree motors at a time. Relative-position motor scans are lup (or dscan ), d2scan andd3scan . The relative-position scans all return the motors to their starting positionsafter the last point. Twomotors can be scanned over a grid of points using the meshscan.Simple reciprocal space scans are hscan , kscan and lscan . The hklscan macromoves the diffractometer along an arbitrary straight line in reciprocal space. Scanssuch as hkcircle or hkradial describe other trajectories. The hklmesh scan measuresintensities over a grid of reciprocal-space points.If you do not know the arguments for a scan or how a scan is used, you can call up itsusage by typing its name with no arguments.17.FOURC> ascanUsage: ascan motor start finish intervals time18.FOURC> hscanUsage: hscan start finish intervals time19.FOURC>When the program does a scan such as hscan ,the following happens: the programwaits for motors to stop moving, calculates (H, K, L )for the current position and thenscans H,holding K and L fixed for a reciprocal space scan along the H direction.19.FOURC> hscan .9 1.1 20 1Mon Feb 15 01:50:33 1994Scan 1 Mon Feb 15 01:50:33 1994 file = cu110/90_01_31.ahklscan 0.9 1.1 0 0 0 0 20 1# H K L Detector Monitor Seconds0 0.9 0 0 2604 38939 11 0.91 0 0 3822 38820 12 0.92 0 0 5295 39034 13 0.93 0 0 7259 38789 14 0.94 0 0 9298 38804 15 0.95 0 0 11505 38909 16 0.96 0 0 13907 38821 17 0.97 0 0 16022 39110 112 USER MANUAL AND TUTORIALS INTERIM WORK-IN-PROGRESS (8/16/01) NOT FOR GENERAL DISTRIBUTION