🚀 go-pugleaf

Terry Bollinger has been corresponding with me about his bubble ideas.  This 
has reminded me that Fermilab once had a 15' bubble chamber, and there have 
been many other bubble chambers operated over the years.  

To introduce bubble chambers, I am reminded fo physics folk lore.  It seems
Don Glasser was opening a bottle of beer, and noticed a streak of bubbles 
that appeared as he opened it.  Being a good physicist, he tried to explain
the streak, and concluded that a cosmic ray had passed through the bottle just
as he opened it.  The cosmic ray left ionized beer molecules which then became
the nucleation sites for bubbles which formed in the super heated beer caused
by the decompression of the opening.  Fortunately the beer can had not yet 
been invented, so Don Glasser won a Nobel prize.  Ever since physics students
have been devoted beer drinkers.  

Modern bubble chambers worked with a large piston.  Fermilab's was 15' and 
there was at least one even larger.  Someone correct me but I believe that
there are no bubble chambers currently in operation.  The chambers were 
usually placed inside a large magnet, and surrounded by trigger electronics.  

A particle beam would be directed through the chamber, and when the
the electronics detected an interesting event (like a beam particle in, but no
beam particle out - meaning there had been an interaction) the piston would 
expand the chamber contents.  Some time later, the time determined by the 
bubble groth rate to get optimum resolution, a flash tube would be fired to 
expose film.  The film was then sent of the measureing machines where the
tracks (in 3 D) were measured, and computations made on the results.  

Now why does this relate to Terry's bubble ideas?  Well sometimes the chambers 
were operated with liquid D2.  Remember, the expansion of the chamber forms 
bubbles.  These colapse some time later.  Perhaps these collapsing bubbles 
cause D - D interactions.  As Terry would say a "far fetch".

What we need is to look at some "double expansions" where the bubble chamber
was expanded a second time shortly after the first expansion so tracks coming 
off a bubble collapse might be seen.  I know that the Fermilab chamber 
sometimes triggered more than once per spill, i.e. at less than a second after
the first expansion.  Then there was the PPA chamber that went 20 times a 
second.  

So does anyone out there know where to finde such film.  (Douglas Morrison are
you listening?)  

The problem is that bubble chamber experiments are very expensive, and no one
would likely support running one for such a wild idea.  But if the right old
film can be found, it might be worth looking.  

Tom Droege