[ RadSafe ] Franz and neutrinos

[Arland Carsten]

Hi to all,

I was interested in your comments about neutrino research, particularly that done at Brookhaven, since I started as a Radiological Physics Fellow at BNL in
1954, and joined the Health Physics Division in 1957.  Although not a physicist I  was interested in the neutrino work.  This was partly due to the fact that I
knew Lederman and Schwartz quite well from playing many hours of poker with them.  (This was before poker became a national past-time.)

The other part of the BNL neutrino story (solar neutrinos) involved Ray Davis Jr. who also got the Nobel Prize for work which was equalty, or more, interesting
than the work at the AGS.  Ray (who I also knew well) was the first one to detect solar neutrinos.  He is quoted as saying, "Neutrinos are intersting particles,
so tiny that they can pass straight through everything , even the earth itself without slowing down."

He devised a method based on the theory that the neutrinos produce radioactive argon when they interact with a cholorine nucleus, His first detctor was in an
Ohio limestone mine 2,300 feet below ground. His large experiment was 4,800 feet below ground in a 100,000 gallon tank of (I believe a perchloro compound) at
the Homestake Gold Mine in South Dakota.  He found that there were only 1/3 the neutrinos that standard theories would predict.

In the 1990s, the so called "solar neutrimo puzzle" was confirmed in a number of different studies.  It is now quite well accepted as evidence that the three
known types of neutrinos could change into another type known, by "neutrino oscillation"  This implies that neutrinos have mass, which is not included in the
current standard model of elementary particles.  Davis's detector was sensitive to only one form of neutrino, so he observed less than the expected number.

Most of the above information is about two years old, which means that neutrino experiments being done at  the GALLEX
experiment in Italy, those at the Sudbury Neutrino Obervatory (SNO) in Canada and others might have new information.


Arland  (Red) Carsten,  Ph.D., CHP

Senior Scientist, Consultant
Brookhaven National Laboratory



JPreisig at aol.com wrote:

> Hmmmmmm,
>
>      This is from:      jpreisig at aol.com     .
>
>      Hi Radsafers and Franz,
>
>           Neutrino (and antineutrino) work isn't always done at particle
> accelerators.
>
>           Lederman, Schwartz, Steinberger and others did their neutrino work
>      at the Brookhaven Alternating Gradient Synchrotron (AGS).  There was
>      considerable shielding between the AGS and the eventual detectors
>      (of the experiment), I guess to get rid of most of the other produced
>      particles, thereby producing a relatively pure neutrino (or antineutrino)
>      "beam".  The work is described in the book by Cahn and Goldhaber
>      "The Experimental Foundations of Particle Physics".  Reines & Cowan's
>       work (see below) is also described in this book.
>
>            There are electron neutrinos,  muon neutrinos and tau neutrinos,
>       right???
>
>             Reines and Cowan did their neutrino work at one of the reactors
>       at Savannah River Lab (USA).  Reactions were like:  antineutrino on
> proton
>       gives positron and neutron.  So, if you can make the preceding reaction
>       occur, one can produce positrons and neutrons, each of which can be
>       detected with some effort.  One can use the reaction positron plus
> electron
>       gives two gammas, which are readily detectable.  One can detect neutrons
>       in many ways, perhaps even by using Bonner sphere detectors.  Read what
>       Reines & Cowan did in the aforementioned book.
>
>            Lederman, Schwartz and Steinberger (and others?) received a Nobel
>       prize in physics for their work.
>
>            Some of the people involved in this detection of Uranium (235???)
>       at airports and elsewhere, are pretty heavy, scientifically speaking.
>       And, right now, they probably won't tell you much about what they are
>       doing.  Many active USA D.O.E.  (Department of Energy) workers
>       don't post to RADSAFE regularly either.  I haven't worked for Brookhaven
>       Lab for many years now.
>
>            Get the book, Franz, from your library or by buying it.  It's good
>       reading.
>
>            Punxatawney Phil (the local Pennsylvania groundhog) crossed me
>       again today, and called for 6 more weeks of winter weather.  I guess he
> goes
>       with the safe bet... it keeps him warm and well-fed.
>
>            Regards,     Joseph R. (Joe) Preisig, Ph.D.
>
>
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