Hi all, I've finally found out how to tune the BFS geometry by looking at the brag source code in src/fms2. I inverted some equations that returned the global positions of the detectors in order to get the "clearence" and "refdist" parameters. I could then easily find these params, given the global positions returned by the DB (all BFS det and magnets). Below, you can find the results to be inserted in a kumac with the BFS on (note that D3 is ok + some dets don't have any tunable Y position parameter). These numbers were obtained by comparing the 12 deg. run 5609 to brag. If it turns out that some DB values are wrong, let me know asap. More generally, if it is the wrong way to do it in brag, please provide a good solution. Ciao Djam * T3 default (refdist: -185, clear: 2) set_param t3 refangle 0.1637 set_param t3 deltay 0.85 set_param t3 clear 2.47775 set_param t3 refdist -188.465 * T4 default (refdist: -180, clear: 2) set_param t4 refangle -1.737 set_param t4 deltay 0.28 set_param t4 clear 1.74012 set_param t4 refdist -183.273 * T5 default (refdist: 175, clear: 2) set_param t5 refangle -3.789 set_param t5 deltay 0.24 set_param t5 clear 2.09483 set_param t5 refdist 171.808 * TOF2 default (refdist: 234, clear: 2) set_param tof2 clear 5.43122 set_param tof2 refdist 230.615 * RICH default (refdist: 346, clear: 6) set_param rich clear 9.10071 set_param rich refdist 360.44 * D4 default (refdist: 0, clear: 1) set_param D4 clear -7.17012 -- Djamel Ouerdane ------------------------------------------o | Niels Bohr Institute | Home: | | Blegdamsvej 17, DK-2100 Ø | Jagtvej 141 2D, | | Fax: +45 35 32 50 16 | DK-2200 Copenhagen N | | Tel: +45 35 32 52 69 | +45 35 86 19 74 | | http://www.nbi.dk/~ouerdane | | ouerdane@nbi.dk | o---------------------------------------------------------o
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