123629832
Intense Coherent Submillimeter Radiation in Electron Storage Rings
Energetic electron bunches in storage rings produce pulsed bursts of incoherent synchrotron radiation. It is pointed out that they should also produce a roughly comparable power output of coherent radio-frequency radiation. Thus electron storage rings, in addition to their intended purpose and their secondary use as intense sources of x rays, might additionally serve as pulsar simulators, producing a similar spectrum of coherent emission, the properties and modification of which could be studied in the laboratory. A spontaneous bunching of electrons (artificially bunched here) might be evidenced as ''superbunching.''
121467224
PARITY NONCONSERVATION IN NUCLEI
BS>The influence of the known weak interactions on the parity of nuclear states is discussed. Derivation of a parity nonconserving interaction rests on the assumption of a current-current hypothesis for the weak interactions. Consequently, observation of parity impurity effects would be an important confirmation of this hypothesis. A simple approximate method of treating the nuclear parity impurity is developed and applied in an effort to find experimental situations favorable to observation of effects due to such impurity. Parity-forbidden alpha decay from excited states of light nuclei and certain electromagnetic transitions in the heavy nuclei appear to be promising. Special attention was paid to the internal conversion electrons from the 123kev transition nn Lu/sup 173/ whose polarization is estimated to be about 0.4%. An effect on polarized neutrons analogous to optical rotation is also discussed. (auth)
37852212
Quark matter or new particles?
It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the ..cap alpha.. particle, composed of spin-zero pairs of each of the baryon octet (an ''octet'' particle).
123416974
Theory of pulsar magnetospheres
There is a wide range of fundamental physical problems directly related to how pulsars function. Some of these are independent of the specific pulsar mechanism. Others relate directly to the physics of the pulsar and already shed some light on the properties of matter at high density (\ensuremath{\sim}${10}^{15}$ g/cc) and in strong magnetic fields (\ensuremath{\sim}${10}^{12}$ G). Pulsars are assumed to be rotating neutron stars surrounded by strong magnetic fields and energetic particles. It is somewhere within this "magnetosphere" that the pulsar action is expected to take place. Currently there has been considerable difficulty in formulating an entirely self-consistent theory of the magnetospheric behavior and there may be rapid revisions in the near future, which is all the more surprising since many of the issues involve "elementary" problems in electromagnetism. One interesting discovery is that charge-separated plasmas apparently can support stable static discontinuities.
120326165
Airy structure in inelastic light-ion and light heavy-ion scattering
We suggest that the transparency displayed by some light heavy-ion systems, such as {sup 16}O+{sup 16}O, {sup 16}O+{sup 12}C, or {sup 12}C+{sup 12}C, which manifests itself by the emergence of Airy structure in the elastic scattering angular distributions and excitation functions, could also have observable consequences in some inelastic channels. Indeed benchmark calculations for the {alpha}+{sup 40}Ca light-ion system, where a similar mechanism dominates elastic scattering at low energy, reveals the persistence in inelastic scattering of the interference mechanism between the barrier-wave and internal-wave components of the scattering amplitude which underlies the Airy structure in the elastic channel. These calculations seem to point to new phase rules between the elastic and inelastic angular distributions.
120454940
Quantum calculation of the barrier and internal wave contributions to light- and heavy-ion elastic scattering
We propose a new technique allowing the decomposition of the light- and heavy-ion elastic scattering amplitude into its barrier and internal wave components as defined by Brink and Takigawa. The method requires only minimum programming as it makes use of the reflection coefficients generated by any optical model code. Also, it can be applied to a wide range of potentials including folding model and model-independent potentials. The use and physical interest of the method are illustrated by applying it to a few representative examples ranging from ..cap alpha.. to heavy-ion scattering.
124193977
High-spin states in Ne-20 reached by O-16 (alpha, alpha) O-16 elastic scattering
122563522
DESIGN OF THE LOW-BETA, QUARTER-WAVE RESONATOR AND ITS CRYOMODULE FOR THE SPIRAL 2 PROJECT
The SPIRAL 2 project, to be built in GANIL, consists of a 40 MeV linear accelerator for 5 mA of deuterons and a target-source complex for the production of exotic isotopes. The accelerator is also optimised to accelerate q/A = 1/3 ions up to 14.4 MeV/u. The three stages of the linac are a RFQ (up to 0.75 MeV/A), a low beta (0.07) and a high beta (0.12) sections consisting of quarter-wave, 88 MHz superconducting resonators. This paper focuses on the low beta cavity and its cryomodule. The cavity nominal accelerating gradient is 6.5 MV/m in operation. RF properties of the cavities are dealt with, as well as the mechanical ones: helium pressure effects, tunability, vibrations. The cryomodule is designed so as to save longitudinal space and therefore is partly assembled in clean room.