A Vacuum Cold Bore Test Section at the CERN ISR
A 2 m helium cooled vacuum test section has been inserted into the CERN ISR to investigate problems which could be encountered in future cold bore proton machines. The UHV bore is cooled from the helium bath via a variable pressure gas filled space which enables operation at any temperature between 2.5 K and ambient. Temperature and degree of surface contamination can be remotely controlled. First observations from nominally clean and from hydrogen contaminated surfaces operating at temperatures close to 4.2 K are presented.
Proton--proton intersecting storage accelerator facility ISABELLE at the Brookhaven National Laboratory
The intersecting storage accelerator facility ISABELLE proposed for construction at the Brookhaven National Laboratory is reviewed. ISABELLE would permit the exploration of proton--proton collisions at center-of-mass energies continuously variable from 60 to 400 GeV and with luminosities of 10/sup 32/--10/sup 33/ cm/sup -2/ s/sup -1/ over the entire energy range. The facility would consist of two interlaced rings of superconducting magnets, operating at 40 kG, in a common tunnel about 2.6 km in circumference. The proton beams would collide at six intersection regions where particle detecting systems would be located. Protons of about 30 GeV from the AGS will be accumulated in each ring to obtain the design current of 10 A prior to their acceleration to the final energy. In this paper the design philosophy underlying the principal design choices, as well as a brief description of the major accelerator systems and the conventional structures, is presented. An overview of the physics potential provided by ISABELLE is then given. The large extension of the center-of-mass energy range combined with the very high luminosity would provide unique possibilities for the investigation of the questions of greatest current interest in particle physics. Arguments, based on the available data and reasonable theoreticalmore » concepts, are presented that suggest strongly that the intermediate vector bosons required for a unified weak and electromagnetic field theory should be discovered. They should be studied in detail. The hadron production at high transverse momentum, the energy dependence of the strong interactions, and the possible search for new, massive particles are also discussed. The paper concludes with a detailed beam analysis, the various limitations on beam current, the procedures followed in optimizing the luminosity, and a justification of the projected performance levels.« less
Can Centauros or Chirons BE the First Observations of Evaporating Mini Black Holes
We argue that the signals expected from the evaporation of mini black holes — predicted in TeV-gravity models with large extra dimensions, and possibly produced in ultrahigh energy collisions in the atmosphere — are quite similar to the characteristics of the Centauro events, an old mystery of cosmic-ray physics.