🚀 go-pugleaf

In article <69666@ut-emx.uucp>, johncobb@ut-emx.cc.utexas.edu (John W. Cobb) writes...
>In article <92091.143213DOCTORJ@SLACVM.SLAC.STANFORD.EDU>, Jon Thaler writes:
> 
> 
> 
>|>So, how are we to judge the merits of the various competing proposals?
>|>Cost is surely a relevant consideration, but not the only one.  The
>|>possibility suggested by HL above is also relevant (ie, it may be
>|>cheaper if we wait).  I don't think that the case has been made here,
>|>though.  For example, when the hi-Tc superconductors were discovered,
>|>it was immediately suggested that perhaps the SSC should be delayed by
>|>a few (five or so) years and then built with what would surely be a
>|>much less expensive magnet technology.  I think that it is safe to say
>|>that hi-Tc technology development has been slower than was anticipated
>|>during that first rush of adrenaline, and will not be able to provide
>|>any significant benefit to the SSC by 2002.  Of course, I'm open to
>|>evidence to the contrary.
> 
>There are of course other possible advances in accelerator technology.
>One example is the plasma High Energy Accelerator. The idea is that you
>build a slow wave structure using a laser beam to modulate a plasma. Then
>you can get accelerating gradients much higher than is possible in current
>accelerator designs where the gradient is limit by breakdown voltages. And
>if you want to go further out, you can talk about crystal accelerators
>where you use periodic crystals structure along with slightly off axis
>lasers to create an accelerator with even larger gradients. Initial
>calculations show you could get SSC-type energies in a device the size
>of a laboratory workbench. 

I must confess that in my SSC-loving heart I still have a problem with how 
things have been handled because of the issue that you raise here.  None
of the novel accelerating schemes which are being worked on are anywhere near
replacing standard technology.  But there has only been a relatively small
amount of money spent on such ideas (order $10-50 million, I think).  What
if we invested a Billion dollars?  It seems like there might be an opportunity
for tremendous gain.  We're going to spend the money on the SSC's conventional 
technology anyway.

The reason that we don't is that the particle physicists are in a race against
time.  You don't do good physics by verifying someone elses result.  This
competative incentive to move fast is a strong driving force in the advancement
of science.  For the most part it is a very good thing.  However, in this case
I wonder if we are leaping just a little to soon, without looking quite enough.

>However, if you are a HEP science
>advocate, this prospect is unacceptable. We have X thousand scientists and
>technicians who are trained in HEP experiments. How are we going to
>mothball the program for 10 to 20 years and then just magically resurrect
>this technical expertise? Of course we can't. If we don't have a list of
>current experiments which will accomadate this personnel, then the entire
>progam may go into a declining phase where jobs are scarce, new talent is
>forced out because those with more experience are always sufficient to 
>fill up the few slots. In the end the discipline risks becoming stale
>and un-inventive. 

True.  This is a valid point for the people concerned with the long-term health
of their research field.  Can you blame them?  We have an interest in keeping
all of our most fruitful research programs healthy.  It's in the national
interest.  I suppose that the question is how best to accomplish this goal.

>But where does it end? It's like a junkie. We need our next HEP experiment
>fix to salve the jitters, but as we built it we find that we need to 
>incorporate new talent and therefore expand the progam, so 10 years from
>now we'll need another fix of even larger proportions. Take a look at the
>proportion of memebers of the American Physical Society that are in high
>energy. It has steady grown, percentage-wise, from very small to quite
>substantial. Well, we seem to be building the SSC and that should last
>for the rest of the millinuem, but what then? 

If more and more scientists move into high-energy physics, this is an
indication that HEP is where the action is.  Each scientist judges for
himself what seems most interesting to pursue.  If more people are going into
HEP, this is an indication of the healthy productivity that the field has had
and seems likely to continue to have in the future.  What's wrong with that?
Would you like to decide from you armchair what each of us should work on
according to *your* sense of what's interesting or important?  

>I think HE physicists are
>headed for some really tough and painful choices. It is for this reason
>that I chose not to pursue a career in HEP. No matter how you slice it,
>I don't see anybody funding a mega-SSC as a follow-on.

Fine.  That's your choice.  And no, there is no mega-SSC on the drawing board.
But there are a host of interesting machine ideas, including a TeV
electron-positron collider, various meson factories, heavy-ion accelerators,
and an assortment of new-technology projects which are still just twinkles in
their designers' eyes.  I don't think that accelerator-based HEP is going to 
wither away any time soon.  But the SSC is likely to be the biggest machine of
its class ever to be built (in our lifetimes anyway).

-Scott