Black Plaid

Lookie! Got the blog working again, with old entries and everything!

Now back to work..

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...

Continue reading "Blog HOWTO" »

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

Continue reading "And Even More Wide Strip Efficiencies" »

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%.

Continue reading "Wide Strip Efficiencies" »

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.

Continue reading "Fibre Position Extravaganza" »

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.

Continue reading "More doublewide strips" »

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?

Continue reading "Double wide double fibre vs Two strips" »

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

Continue reading "Very Wide, Two-fibre strips" »

OK, let's see how things work when we make the strip very wide indeed. Below are the results for 40cm-wide strips with a single fibre (MINOS-style).

Continue reading "Daya Continued: Very wide strips" »

Below are plots showing the path-length of photons in the scintillator and the number of bounces, for both simulated MINOS and OPERA strips. The blue curves show the distributions for photons that survive to the fibre, while the black curves are photons that miss the fibre.

The bottom line is:
Photons tend to travel further in MINOS strips, which isn't too surprising.
Photons tend to bounce more often in the MINOS strips, which again isn't too surprising.

Update: Rebuilt to get pathlength right.

Continue reading "Scintillator pathlength/ bounces" »

The code evolves some more. Support for multiple fibre in place but untried.

Below, I show what happens to a MINOS strip if you move the fibre to 1.5cm off the axis. Interestingly, the total response of the strip drops only a small amount, though obviously the position response changes substantially.

Continue reading "Moving the fibre" »

Here's the latest result on the Daya Bay scintillation work.

This time I've got the full fibre model included, as well as the scintillator optics.

Continue reading "Daya Bay Veto simulation, round 3" »

That only took about 3 hours to do. Alex of course has all of the Tufts minos computer hotwired so that mysql refused to work. Fiddled with the scripts, reset the root password, all that jazz. Then I managed to install moveable type without killing myself, and now I get to actually make an entry...