Black Plaid

Below is a more extreme case... a 16cm wide strip with a fibre at each side.

Below is a simple comparison: imagine two MINOS-like strips, 4cm wide.

Now imagine a single double-wide (8cm) strip with two fibres in it.

How well do these two cases compare?

A few more cases of double-wide strips with two fibres, moving the fibres around to try out different solutions. Again, an 8cm-wide strip, 1cm thick.

The results:
+/- 3.8 cm: 8.9% each fibre
+/- 3.0 cm: 9.7%
+/- 2.0 cm: 10.0%
+/- 3.0 cm: 9.8%

Thus, it's pretty much insenstive to fibre position, although my prediction is that you do slightly better if you put your fibres about 1-2 cm from the edge of the strip.

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.

Factory results continue. here's the results for the wide fibres requested:

The cases here are
(8cm1f) An 8cm-wide strip with a single central fibre
(8cm2f) An 8cm-wide strip with two fibres, like two MINOS strips joined together

(20cm4f) A 20cm-wide strip with 4 fibres at +/-2 and +/- 6cm.
(20cm5f) A 20cm-wide strip with 5 fibres, like 5 MINOS strips stuck together.

The efficencies are:

(8cm1f) 11.2%

(8cm2f) 19.8% very similar to the standard MINOS strips

(20cm4f) 17.0%

(20cm5f) 20.5% again, very similar to the standard MINOS strips

Again, statistical uncertainty is roughly +/- 0.2%.

Two more cases for Laurie:

(20cm5f2cm) 5 fibres spread across a 20 cm wide strip, as before, but make the strip 2cm thick (instead of 1 cm).
(20cm6f) 6 Fibres spread across a 20 cm wide stirp.

(20cm5f2cm )14.7% (compare to 20.5% for a 1cm-thick).
(20cm6f) 23.5%

As usual.. increasing the number of fibres helps (as always) and having a thicker counter helps. But you're better off having two 1cm counters than a single 2cm counter.

And, of course, these multifibre strips are probably a pain in the ass to manufacture.. but I'm no expert on that.

---Nathaniel

Here's some tricks I'm using to help manage this blog, particularly with ROOT.

Because I sometime do the same thing multiple times, I'm often pretty careless with filenames, particularly for plots. So, I've decided to organize all of my plots by date; I'm usually not stupid enough to make the same filename muliple times on the same day.

So, I create a directory in my blog:
$(HOME)/www/blog/upload/2006/07/24/
That is, my main blog directory, an upload path, and the current date (24 July 2006) in a well-formated fashion.

For one-off uploads, I use the built-in MoveableType file uploader (which ignores the "day" part of this path and just uses month). But I make a lot of plots; for that, I like to use a ROOT macro, which I explain below...