Fibre Position Extravaganza
Below are the efficiencies for getting to the fibre (not in it) for a standard MINOS strip with multiple fibre configurations. The configurations I use are shown below:
New: Two more configurations. Like (e), but:
(f) three fibres at +/-1.2cm and 0cm
(g) three fibres at +/- 1.0cm and 0cm.
The efficencies are:
(a) 19.1%
(b) 28.2%
(c) 31.9%
(d) 29.8%
(e) 40.3%
(f) 41.9% new
(g) 41.6% new
The statistical uncertainty is about 0.2% in each case.
Below the fold is an illustration of how far the photons have to go before they hit the fibre, and the pathlength vs transverse position.
Below are the Y-profile plots (i.e. efficiency as a function of position across the strip).
The next two plots show how far photons have to go before they hit the fibre, as a function of where they started. The first shows the 2-d plot (with a logarithmic Z scale). Note the bins along the bottom, which dominate the picture. The second is a profile plot. (Errors indicate error on the mean, not the spread) which shows how this smallest bin pulls the distribution. These are for the standard MINOS strips (case a).
These can be compared the number of bounces before the photon hits the fibre, shown in the follwing plot. Clearly, in my optical model, it's the number of bounces, not the attenuation length, that dominates the game:
