三、
Fermi define the spin of electron you can call the clockwise(three dimension) or counter clockwise.
want more counter quenstion in the science and etc?
Please teach the other non Chiao Tung traditional classmates who is Fermi, who is Prof Wang,
Another subject: who is prof Chang Juei4 Fu? He settle the Semiconductor Lab, and teach President Chang of NCTU, and Prof Guo Shun Fa. Make first transistor. And formor ROC president Chiang and Air Force coomad in Chief visit NCTU.
I am a four dimensional person. While many ROC classmates are fifth person, I wu4 very slowly. I will learn Argentina Tango. Dance with Enemy? Who is ROC's enemy? Hope you understand what is unequal treaty,
Best Regards,
Fan4 Tung3
1/30/2005
21:17 PST
--------------------------------Enrico Fermi Physicist
1901 - 1954 "There are two possible outcomes: If the result confirms
the hypothesis, then you've made a measurement.
If the result is contrary to the hypothesis, then you've made a discovery."
In early experiments, I attempted to detect neutrinos from a reactor, using the chlorine-argon detection method suggested by Bruno Pontecorvo (in 1946). In this method, a 37Cl atom reacts with a neutrino to make an 37Ar atom. Argon is a noble gas and is easy to separate chemically from a large amount of chlorine-rich solvent. It is radioactive with a half-life of 35 days and can be counted with a gas-filled proportional counter. A first attempt, exposing a 1000-gallon tank of carbon tetrachloride at the Brookhaven Graphite Research Reactor, failed to detect any signal, as the neutrino flux at this reactor was too small to affect a target of this size. Furthermore, a reactor emits antineutrinos, and the Pontecorvo method only detects neutrinos. It was not known at that time that the two particles were not identical. Later, I built larger experiments, using one of the Savannah River reactors as the neutrino source. I eventually set a limit on the neutrino flux that was a factor of 20 below the antineutrino flux measured by Reines and Cowan in their elegant experiment that won Fred Reines his Nobel Prize. "for pioneering experimental contributions to lepton physics"
Our interest in meteorite exposure ages continued for many years. We also worked on measuring cosmic-ray production of 37Ar and 39Ar in a variety of freshly fallen meteorites. Our greatest success in this work was with the Lost City meteoriteA new measurement of the nuclear reaction 3He+4Heg7Be+g by Holmgren and Johnston in 1958, suggested that one of the terminal reactions in the proton-proton chain would produce energetic neutrinos which could be measured by the chlorine-argon radiochemical method. Encouraged by these developments, and with the support of the Brookhaven National Laboratory and the U.S. Atomic Energy Commission, I built a much larger experiment in the Homestake Gold Mine in Lead, South Dakota. The detector itself consisted of a 100,000-gallon tank filled with perchloroethylene, a solvent most commonly used for dry cleaning of clothing. The experiment was located nearly a mile underground, at the 4850 foot level of the mine. Initially, we observed no solar neutrino signal and expressed our results only as upper limits. Subsequent refinements in technique and, particularly, in counting methods, continued over the years, producing a solar neutrino signal approximately one-third of the expected flux from the standard solar model calculated by John Bahcall. This was the genesis of the so-called "solar neutrino problem". 【物】微中子