BigBite Drawings, Schemes, Pictures and Photos
Various BigBite Schematics:
I got a lot of various drawings of BigBite from Peter Monaghan. Here they are:
peterDrawings.pdf
peterDrawings2.pdf
peterDrawings3.pdf
Here is also my hand-made drawing of BigBite with approximate measurements of the
distances between various parts of the spectrometer:
mihamBBScheme.pdf
BigBite drawings:
The following 3D drawings of BigBite were made with a free JT2GO software and a JT file
designed for our experiment. The file contains a detailed drawings of the complete
experimental setup for the E05-102 experiment. You can turn on/off various parts of the
spectrometers, target etc. You can also measure distances between various parts of the
spectrometers. You can find this file in the following directory:
M:\ideas\JT_Files\HallA
This file was made by Alan Gavalya. When I visited him, he warned me, that our file
was (at that moment) not complectly correct. The BigBite spectrometer was not positioned
at the correct angle. He told me, that he will correct this mistake and produce a new
JT file for us. Unfortunately, this is not the only problem. Various distances for BigBite
spectrometer, such as distance from the target to the magnet, and distance from the target
to the MWDC, etc. are not correct. We compared my hand made measurements with the values from
his drawings and they did not match. In order to correct these mistakes he needs to include
Surey data into the drawings, but this can not be done instantly, because he first needs
to determine where the fiducial points ly with respect to the frame of the detector package.
Apperently survey group has these measurements, but has yet not been able to provide them to
Alan. Therefore we need to be careful when we use this JT file for determining distances.
BigBite Survey report - Additional information
Here is the survey report for the E05-102 experiment:
DT_A1229.pdf
This report contains results for only two points. We believe that these two points lie
in the middle of the frame, that supports wire chambers and scintillators. Fiducial
points are also mounted on these frames. To be sure, that we have correct information
we asked Kelly Trembly from Survey group to give as also the actual measuremets for
each fiducial points. Here is the email, that he wrote me. There are 4 fiducial points
on the first frame and 6 fiducial points on the second frame.
-----------------------------------------------------------------------------------
Miha - sorry I wrote something incorrectly. I stated only 3 points were identified in the 1st set of 3 data sets I just sent. That is incorrect - we surveyed 6 points (A to F). I should re-read things before I send them out, rather than after, but it is late on Friday....
By surveyed, I mean we located the points in our overall geodetic coordinate system.
take care,
Kelly
------------------------------------------------------------------------------------
Hello Miha,
Here is the data we talked about for the big byte detector package. There are 10 fiducials on the frame that holds the 2 detectors. In our overall coordinate system, (geodetic) fiducials have the same coordinates. However, the fiducial coordinates are different for each of the detectors relative to the detector centers. I hope that makes sense, if not let me know.
best regards,
Kelly Tremblay
The geodetic hall target which the report is based on has the following coordinates (meters z,x,y) with the main straight ahead beam having a yaw angle of +142.5 degrees in our geodetic coordinate system.
hall A target (ideal) 79606.96892 59967.04157 2100.03421
the correction for curvature at this point is 12.206 millimeters (applied to the Y coordinate).
3 pieces of information -
=========================================================================
overall geodetic coordinates (corrected for earth's curvature in the Y coordinate. (meters and Z,X, Y coords
(note only 3 points are identified)
Final object point coordinates and standard errors
Z X Y SZ SX SY
TBA 79609.02440 59970.73701 2099.80731 0.00006 0.00006 0.00005
TBB 79607.95450 59971.16468 2099.80379 0.00006 0.00006 0.00005
TBC 79608.01566 59970.57548 2100.90628 0.00007 0.00006 0.00006
TBD 79608.57524 59970.35411 2100.90368 0.00006 0.00006 0.00006
TBE 79608.68002 59969.87988 2101.74535 0.00006 0.00006 0.00006
TBF 79607.61103 59970.30655 2101.74201 0.00007 0.00006 0.00006
=========================================================================
downstream detector fiducials (millimeters)... (z,x,y)
TBA 223.11760 -575.51790 -1171.92130
TBB 220.48860 576.85750 -1173.51710
TBC 222.44670 300.42570 47.08130
TBD 223.94280 -301.36850 42.95070
TBE 223.77600 -575.34750 975.06910
TBF 220.94060 575.89770 973.89280
TBH -713.72570 335.88410 -726.24070
TBG -713.10410 332.26860 869.18830
TBJ -711.67820 -339.10770 -732.58750
TBK -711.49170 -339.94220 871.80150
CL 0.0 0.0 0.0
=========================================================================
upstream detector fiducials (millimeters)... (z,x,y)
TBA 1180.56980 -576.22950 -1227.37320
TBB 1181.91920 576.14810 -1228.96450
TBC 1183.19260 299.70610 -8.36750
TBD 1182.61000 -302.08970 -12.50050
TBE 1181.70340 -576.07030 919.61700
TBF 1182.84250 575.17780 918.44530
TBH 246.97730 338.39980 -781.48240
TBG 247.93910 334.77560 813.94650
TBJ 246.69290 -336.59500 -787.83190
TBK 247.23120 -337.43680 816.55690
CL 0.0 0.0 0.0
BigBite Measurements:
Here are the photos with the measurements of BigBite detector package, that Simon and I made
in December. We measured the position of the fiducial points with respect to the detector package
frame. This could be used for the correct positioning of the spectrometer in the Hall.
Last modified: 12/21/09
