« PrécédentContinuer »
19 shape of a football. Superdeformed nuclei are approximately twice as elongated as a football. Existing theories cannot explain the transition of nuclei into these shapes. The proposed Gammasphere detector, a gamma ray detector for nuclear structure research which consists of 120 separate and complex Germanium detector units is designed to address this rapidly evolving area. At the Bates Linac at MIT, an international scientific team made the first complete measurement of the charge distribution of the deuteron, which is composed of one proton and one neutron. New techniques and more precise
data identified a deformed as well as a spherical component of the electric
charge distribution of this simplest possible composite nucleus. The aspect of the nuclear force that gives rise to this deformation could form the basis
of improved theories of superdeformation.
A combination of results from
experiments using the Tandem/AGS at BNL and the Super Proton Synchrotron at the European Organization for Nuclear Research (CERN) have measured the temperature of nuclear matter produced by relativistic heavy ion collisions. These experimental results, combined with extended theoretical calculations,
confirm that even higher temperatures will be produced by the proposed
Relativistic Heavy Ion Collider (RHIC) facility, which I will discuss shortly. RHIC will permit temperatures high enough to study, for the first time, the quark-gluon plasma, the fundamental quark particles in the nucleus, and the strong force that holds them all in place.
FY 1991 NUCLEAR PHYSICS BUDGET REQUEST
The FY 1991 budget request for the Nuclear Physics program is $330.7 million. Of that total, $215.5 million is for Operating Expenses, $26.7 million is for Capital Equipment, and $88.5 million is for Construction (Table 5).
The FY 1991 Operating Expenses request will maintain an approximately constant level of program activity in low and medium energy physics, in heavy ion nuclear physics, and in nuclear theory. The FY 1991 request provides for an increased level of support for the Continuous Electron Beam Accelerator Facility (CEBAF) with $12.2 million allotted to R&D, testing and prototyping of accelerator components and support of detector development, and $12.4 million for start-up of laboratory operations and accelerator commissioning. Already, 245 physicists from 60 institutions have submitted 47 research proposals for experiments at CEBAF. From these proposals, a program of experiments will ultimately be selected to be carried out when the facility goes into operation in FY 1994. Special emphasis will continue to be placed on effective use of the upgraded accelerators at the University of Washington, Texas A&M University, and Yale University as well as the Alternating Gradient Synchrotron at Brookhaven. At the University of Washington, the second year of operations of the Nuclear Theory Institute will provide an increased number of study programs and workshops.
Research and development in support of the next generation of accelerators will also be supported by the Operating Expenses request, including work at
Medium Energy Nuclear Physics
BNL to extend the scientific and technical basis for the proposed Relativistic Heavy Ion Collider.
The Capital Equipment request of $26.7 million will provide for instrumentation required to effectively use the national accelerator facilities operated by the program. These funds will provide such equipment as particle detection systems, data acquisition and analysis systems, and instrumentation to improve the performance of the accelerators. The Capital Equipment request also includes funds to start assembly of the Sudbury Neutrino Observatory, a laboratory for neutrino astrophysics, to be built as a collaborative U.S., Canadian, and United Kingdom project. The request also includes funds to begin fabrication of Gammasphere, the gamma ray detector for nuclear structure research that I mentioned earlier. Finally, the FY 1991 request will provide for general purpose equipment to meet the laboratory-wide needs of LBL.
The FY 1991 Construction request for Nuclear Physics is $88.5 million.
(Table 6) of that amount, $65.0 million is for CEBAF, an accelerator with electron beams in the energy range of 0.5 to 4.0 GeV that will provide access to the critical transition region between the traditional li.e., nucleon) and the emerging (i.e., quark) descriptions of nuclear matter. CEBAF is expected to revolutionize the production and collection of data for nuclear physics research in the area of electromagnetic interactions with nuclei. The FY 1991 construction funds will be used for continued construction of the beam enclosure tunnel and support structures as well as for major hardware