From: hallam@zeus02.desy.de (Phillip M. Hallam-Baker)
Subject: Re: Supercollider "For" or "Against"
Reply-To: hallam@zeus02.desy.de
Organization: DESY ZEUS Central Data Acquisition
Date: Mon, 27 Jul 1992 11:55:23 GMT

In article <01GMUWFKMPZK001FEW@utarlg.uta.edu>, B645ZAW@UTARLG.UTA.EDU
(Stephen Tice) writes:

[fisrt half is in another post]

|>As for PHB, you be the judge of what to make of Doctor Hallam-Baker's
|>guesses, and research skills. {Rest assured PHB, there's plenty more
|>where this came from. Did you really think that I would rely on only
|>one source -- especially The Nation -- especially when I noted that I 
|>selected it just to spin you up.} Let's see if I can't add a little 
|>torque to the spin. 

Sounds like Tice has something of a personal animosity here. Could it
possibly be that after I made some comments about him being a member of
the church of the risen Perot he is out onn a vendetta? Surely not.
Perhaps he had the brain to be able to work out what the organisation in
the header of my posts was and thought he could use that to get at me?

|>== Yet Another Item == "Terabytes in nanoseconds..."
|>
|>I may type in a fuller treatment of the data-handling problem later in
|>the week. {Mr. Austern, will also want to take note.} I said that the
|>figure being "bandied about" is a "Terabyte per nanosecond," and
|>submit the following teasers. From the Conference Record of the 1991
|>IEEE Nuclear Science Symposium and Medical Imaging Conference, Nov.
|>2-9, 1991, Santa Fe, New Mexico, USA, vol 2 of 3...
|>
|>  "Data Acquisition Studies fro the Superconducting Super Collider"
|>  by Milner, Booth, Botlo, Dorenbosch, and Wang of the Physic Research
|>  Division of the SSC, and Idate, Kappor, and Raj of the University of
|>  Texas, p. 929:
|>
|>    The collider will provide a beam crossing every 16 ns, with a mean
|>    of 1.6 collisions per crossing (100 mb cross section) occuring at
|>    the design luminosity of 10^33 cm^-2 s^-1, giving a 100 MHz inter-
|>    action rate. We can expect data for each event to be about 0.4
|>    Mbyte, giving a raw data rate of 40 Tbyte/s...

That is 0.4 Mbye per 16 ns That is mothing like Terabytes per nanosecond.

|>Perhaps Doctor Hallam-Baker would care to translate that, or he might
|>wish to refer to another paper from the conference...

I gave a figure of 1-2 Mb at 60MHz

1) The 1Mb was an absolute outside figure, this is depending on the zero
suppression techniques used. 

2) A beam crossing interval of 16ns IS 60MHz, try working it out for
yourself 1/60E6 = 16.66E-9.


|>  "High Speed Data Transmission for the SSC Solenoidal Detector," by
|>  Branko Leskovar of Lawrence Berkeley Lab, p. 828:
|>
|>    Abstract. High speed data transmission using fiber optics for the
|>    Superconducting Super Collider solenoidal detector has been studied.
|>    The solendoidal detector system will consist of nine subsystems
|>    involving more than 10^7 channels of readout electronics. Conse-
|>    quently, a new high performance data acquisition system, incorpora-
|>    ting high-speed optical fiber networks, will be required to process
|>    this large quantity of data.
|>
|>    ... Using an open architecture, the data acquisition system will be
|>    capable of processing data rates of several thousands Gbit/s from
|>    detector elements to the online processing system....

Yep you can have Terabit/second but you didn't claim that, you "bandied
about" Terrabit per nanosecond. That is simply untrue. 

|>And rather more amusing, though no less thought provoking, was the article
|>out of COMPUTERWORLD from (7-31-89), "Collider's colossal computing
|>conundrum," p. 4:
|>
|>    ...The lab expects 100 million collisions per second.
|>
|>    ..."Each time particles collide, something happens. But it's not
|>    necessarily something you're interested in," Gilchriese said.
|>    [Gilchriese was then associate director of the physics research
|>    division of the supercollider lab.] He said he expects reductions
|>    to be made from 100 terabytes "to 10, or 100 [megabytes] at most."
|>
|>    No on yet knows how that filtering will be done. Artificial
|>    intelligence programming will not fit the needs of filtering
|>    information, although it can be used in machine control. Gilchriese
|>    said the lab's researchers were exploring neural networks to make
|>    heuristic decisions....
|>
|>
|>I'm tempted to go pull back up your speculations =Doctor= Hallam-Baker,
|>to compare with the material I've presented thus far. ;^)

Actualy my thesis has yet to be submitted (October :-)(Smiley meaning
joke, not happy :(. If I had finished the damn thing I wouldn't waste my
time flaming Zombo-weenies like Tice, however even that is more fun than
writting thesis. 

These passages are all entierely in accord with what I said. Of course
nobody can say now *how* to build such a trigger. The detector designs
aren't even complete. To build the trigger a lot of simulation work
needs to be done. However we have a pretty good idea of which methods
can be used and we do know *A* way to do it. What is not know yet is the
*best* way to do it.


|>I think you'll agree though, that the matter merits a =considered=
|>rebuttal now, regarding professional reputations that is. With all
|>those citations I provided previously on Perot, did you really think
|>I hadn't done my homework on this.

And given how acurate your quotations of Perot turned out to be I did
not doubt that your SSC quotes would turn out to be similarly
irrelevant. Every quote you have given on the technical issues turns out
to show that it is a technological challenge but an achievable one.


|>I particularly got a kick out of your trying to focus the "small
|>science" folk on believing that the SSC would take money from them

I did not mention any other type of science beyond HEP. Stanford Linear
acceleraotr center is BIG science. The fact that they had to cobble
together SLAC and that it turned out that they had cut just a corner too
many and got beaten by CERN isn't their fault. If the SSC is built I
think that HEP would have a job justifying keeping all it's present
facilities, I think that most people in the field accept that the SSC
will replace an existing accelerator lab. However this is not `small
science'.


|>By the by, there's an old rule of thumb I learned doing defense
|>engineering work -- life cycle cost is 3 times R&D. My ballpark guess
|>is that the collider should cost something like $30 billion total over
|>it's lifespan.

So after presenting all these figures from the experts Mr Tice retreats
to using ballpark figures and rules of thumb. 

The problem with Mr Tice's approach is that he is adding in all the
margins for error, contingency reserves etc a second time. Next he will
take his own 30 billion guess and add a factor of three multiplier to
that.

If anyone is intersted in a debate about how the SSC could be justified
I am quite prepared to take part. However I see no reason to continue to
answer Mr Tice's personal attacks. The quotes he has supplied destroy
his own case of $1 billion running costs and Terrabytes per nanosecond.
Yet he takes them as challenging my proffessional competence, despite
the fact that they are entirely consistent with my case.


 |>. And lastly, science being what it is -- there's nothing
|>which guarantees that the physics investigations the SSC is intended 
|>for could actually yield any wothwhile results.

If there could be any such guarantees the results would be known. Talk
about statements of the obvious.

Phill Hallam-Baker