[1350] | 1 | README.test1 DCW Oct 8, 1998 |
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| 2 | |
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| 3 | The first test involves the use of a particle generator called "SprayGun", |
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| 4 | controlled interactively, and an event display. |
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| 5 | |
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| 6 | I have found the VRML display to be particularly useful for this. |
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| 7 | A VRML display can be selected by executing the script "draw3d.script". |
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| 8 | See GEANT4 documentation for more information on setting up a VRML display. |
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| 9 | |
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| 10 | For this test, the spray gun as a particle generator should be selected |
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| 11 | (this is by default): |
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| 12 | |
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| 13 | /fred/gun SPRAY |
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| 14 | |
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| 15 | In addition, the "NORMAL" drawing mode should be selected (this is by default): |
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| 16 | |
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| 17 | /fred/draw NORMAL |
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| 18 | |
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| 19 | Before run initialize, a volume should be specified. See README.volumes |
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| 20 | for details. |
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| 21 | |
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| 22 | Fred displays the event at the end of each event (as activated by command |
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| 23 | /run/beamOn). Drawn in red is the test volume and in green are trajectories |
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| 24 | of geantinos. For every exit intersection of the trajectory with the |
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| 25 | test volume, a white sphere is drawn. For every entry intersection, a |
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| 26 | blue sphere is drawn. |
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| 27 | |
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| 28 | The spray gun creates geantinos emitted from a central point along |
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| 29 | x, y, and z angles in increments of 45 degrees. The position of the central |
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| 30 | point is controlled by the command: |
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| 31 | |
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| 32 | /sprayGun/position <x> <y> <z> [<units>] |
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| 33 | |
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| 34 | The angles are controlled by the commands: |
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| 35 | |
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| 36 | /sprayGun/xSpray <xmask> |
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| 37 | /sprayGun/ySpray <ymask> |
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| 38 | /sprayGun/zSpray <zmask> |
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| 39 | |
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| 40 | Each mask has the following meaning: |
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| 41 | Bit 0: add tracks with a positive momentum with respect to this axis |
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| 42 | Bit 1: add tracks with zero momentum with respect to this axis |
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| 43 | Bit 2: add tracks with a negative momentum with respect to this axis |
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| 44 | By default, xmask=7, ymask=7, and zmask=2, which produces 8 geantinos |
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| 45 | in the x/y plane at angles of 45 degree increments with respect to the x |
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| 46 | or y axes. |
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| 47 | |
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| 48 | To test a volume: interactively place the sprayGun central point along |
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| 49 | difficult positions around or in the volume, and visually inspect the |
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| 50 | results for errors. A knowledge of the difficulties of correctly |
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| 51 | implementing volumes is important to select challenging positions for |
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| 52 | tests. |
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| 53 | |
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| 54 | If an error is found, the xmask, ymask, and zmask values can be specified |
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| 55 | to produce only the one track that causes the error. This can greatly |
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| 56 | simplify the task of debugging. |
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| 57 | |
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| 58 | A example debugging session is included below: |
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| 59 | |
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| 60 | /vis/open VRML1 |
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| 61 | /vis~/create_view/new_graphics_system VRML1 |
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| 62 | /vis~/camera/zoom 16 |
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| 63 | /tracking/storeTrajectory 1 |
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| 64 | /vis/draw/current |
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| 65 | # select test volume BOX |
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| 66 | /fred/volume BOX |
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| 67 | # initialize |
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| 68 | /run/initialize |
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| 69 | # select VRML display |
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| 70 | /control/execute draw3d.script |
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| 71 | # display an event |
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| 72 | /run/beamOn 1 |
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| 73 | # change spray gun to send trajectories at +/- z |
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| 74 | /sprayGun/zSpray 7 |
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| 75 | # change position of particle sources |
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| 76 | /sprayGun/position 1.0 1.0 0.0 m |
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| 77 | # display results |
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| 78 | /run/beamOn 1 |
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