Lateral Marks with ESS A test version is available in http://www.bo.infn.it/opera/scanning/lateralmarks/ since the end of September. Several laboratories started to use it providing constructive feedback. The 42b release (25 Oct 2007) was used for several scan-back and totalscan with the Computing Infrastructure [instead of optical marks]. The full integration with the Computing Infrastructure and DB will require multi-MarkSet support (lateral, optical, … ).

Comments common problems: - evaluation of the initial markset template - transformation from optical markset - frequently usage of manual set (bug, mark segments outside the vacuum channel) - segment finding problems (above the vacuum channel - continuous monitor of the “cloned” mark - reproducibility when mark is above the vacuum channel - 2 mark point couldn’t be enough [i.e. for manual check] some advantages… + scan of plate with bad optical marks (i.e. wrong side) + reduction of scan back time + brick intercalibration matrices close to the identity

News and work in progress A new FlexMapX module in the test home page (2007-Dec-21) (http://www.bo.infn.it/opera/scanning/lateralmarks/ ). The major changes are - integration with the optical mark module - evaluation of affine transformation using 2,3,4 or more marks - choice of how many strip segments (of lateral mark) are to be taken and their inter-distance - a routine to keep under control the "clone problem" [at present without warning] - bug of mark side fixed A bug related to the monitor creation not fixed. Next step can be the markset-markset intercalibration (i.e. optical to lateral, CS to optical, “edge detection” to CS, … )

Spares

Strip finding strategy test revision >= 42 THREE STRIP SEGMENT ARE SEARCHED: [1] the first segment position is searched between the NOMINAL edge and the NOMINAL mark position along a LINE trajectory [2] if [1] is found, the next candidate is searched at +1mm from the [1] in one of field of view [3] if [1] is found, the next candidate is searched at -1 mm from the [1] in one of field of view At least 2 segments are needed. The search path of [1] is from min X,Y to max X,Y To be modified: from the edge to center and stop when the strip is found

Manual Set If Mark Position is MANUALLY SET the strategy is to search all segments in ONE Field of View

The clone problem The "clone" problem: The presence of a duplicated x-strip 1 mm far from the reference one ("clone") caused some failures during tests. See the mark position in the picture. If you suppose to have acquired the wrong one, look at log files to verify the mark positions [They should be within a few 100 microns for one brick set even if the emulsion plate is different. If a mark is 1 mm far along X is the wrong one].