[en] This report discusses the tests of storage cells and new atomic beam sources

[en] Argonne National Laboratory is constructing a 7-GeV Advanced Photon Source (APS). The RF systems of the APS include 10-MHz and 120-MHz systems for the Positron Accumulator Ring (PAR), a multicell 352-MHz system for the booster synchrotron, and a system of mode-damped, single-cell 352-MHz cavities for the storage ring. 11 refs., 3 figs., 6 tabs

[en] During the past year the investigation of micropole undulators continued. These devices were proposed as a means of extending the range of useful photon energies emerging from high energy electron storage rings, as well as devices capable of reducing the size, expense and circulating electron energy required to generate radiated photons of a given wavelength. Various applications of these devices were studied, and the conditions under which alternative types of micropole devices can be employed in storage rings of given characteristics, were explored. During the year covered by this report of activities a patent on micropole undulators was obtained

[en] A transverse bunch-to-bunch feedback system will be installed on the AGS Booster to suppress coherent coupled bunch oscillations driven by the resistive wall impedance of the vacuum chamber when accelerating high intensity proton beams (circulating currents > 3 amp). It is possible to estimate the expected growth rate of the instability by scaling from the machine parameters and measurements made on the AGS. An upper limit of 1.5 x 10³ sec^-1 at 1.5 GeV kinetic energy with Χ = 0 and 0.5 x 10¹³ protons/bunch is obtained for the vertical plane. The position signal of each bunch (h = 3), at two locations separated by one quarter of a betatron wavelength, will be integrated, digitized and stored in a memory whose clock is synchronized with the acceleration frequency. This pair of inputs will be used in conjunction with look up tales, which will be related to a given range of the tune Q, to generate the proper correction amplitude. This will then be D/A converted, amplified and applied to 50Ω traveling wave kickers. The overall time delay will be adjusted to equal or revolution periods in order to permit the necessary digital signal processing (T_o = 0.73 μs at γ = 2.6). An analysis of the performance of this and similar systems for within the bunch modes m = 0, 1 and both zero and non-zero head tail phase shift Χ will be presented. 4 refs., 1 fig

[en] The AGS Booster is being designed as a very versatile particle accelerator. Its primary function is to be a high quality injector to the currently operating Alternating Gradient Synchrotron (AGS). The Booster/AGS combination will produce proton intensities greater than 5 x 10¹³protons per pulse (ppp), and accelerate heavy ions, with mass up to 200, to a maximum energy of 15 GeV per atomic mass unit (GeV/amu). The power supply for the Booster Main Ring (BMRPS) has to accommodate a wide range of cycles and a wide range of operating parameters. The cycles range from storage for several seconds to rapid cycling at 7.5 Hz. The peak output power is 18 MW. This paper will describe the AGS Booster machine powering requirements, the choice of power supply, the a.c. circuit tie-in and its associated problems and some of the details of the design of the BMRPS. 9 refs., 2 figs

[en] The new generation of accelerators for coincidence electronuclear investigations is discussed. The luminosity and beam parameters are calculated for an electron storage ring with an internal target operating in the superthin regime. The advantages and disadvantages in comparison with conventional operation using an external beam and target are described. The intermediate results for 2 GeV electron scattering on polarized internal deuterium target are given (joint Novosibirsk-Argonne experiment). 32 refs.; 5 figs

[en] This paper concentrates on generic R ampersand D and design issues of asymmetric colliders via a specific example, namely a 9 GeV x 3 GeV collider based on PEP at SLAC. An asymmetric e⁺-e^- collider at the Y(4s) and with sufficiently high luminosity (10³³-10³⁴ cm^-2 s^-1) offers the possibility of studying mixing, rare decays, and CP violation in the B bar B meson system, as well as ''beautiful'' tau-charm physics, and has certain qualitative advantages from detection and machine design points of view. These include: the energy constraint; clean environment (∼25% B⁺B^-, B⁰ bar B⁰); large cross section (1 nb); vertex reconstruction (from the time development of space-time separated B and bar B decays due to moving center-of-mass); reduced backgrounds; greatest sensitivity to CP violation in B → CP eigenstate; the possibility of using higher collision frequencies, up to 100 MHz, in a head-on colliding mode using magnetic separation. It is estimated that for B → ΨK_s, an asymmetric collider has an advantage equivalent to a factor of five in luminosity relative to a symmetric one. There are, however, questions with regard to the physics of the asymmetric beam-beam coulomb interaction that may limit the intrinsic luminosity and the possibility of realizing the small beam pipes necessary to determine the vertices. 16 refs., 2 figs

No abstract available

[en] Magnetic structures in modern storage rings provide an assured route to fundamentally new opportunities for extending coherent radiation experiments to the vacuum ultraviolet and soft x-ray spectral regions. Coherent power levels of order 10 milliwatts are anticipated, in a fully spatially coherent beam, with a longitudinal coherence length of order 1 μm. In addition to broad tuneability and polarization control, the radiation would occur in 20 psec pulses, at 500 MHz repetition rate

[en] A recent calculation indicates that a significant fraction of the synchrotron radiation energy will scatter from and penetrate through the PEP vacuum chamber and out into the air of the tunnel. This could pose some difficult problems such as the formation of nitric acid and ozone in the air. In addition, rough calculations show that the coil windings themselves might be subject to high radiation doses, leading to premature failure. The purpose of this note is to give the results of a series of calculations that predict both the energy-loss to the air as well as the absorbed dose to the coil windings due to a synchrotron spectrum continuously striking the vacuum chamber wall. The energy-loss in the air, in turn, is used to estimate the production of nitric acid and ozone in the air. The calculations are facilitated by means of Monte Carlo program that has been developed at SLAC and HEPL from a basic code. In recent years this code, called SHOWER, has been extensively revised, and for this particular use, the photon energy cut-off extended down to 1 keV. It is quite obvious that an analytical treatment of this problem can easily be made, since the bulk of the calculation involved Compton scattering in the first few layers of aluminum followed by photon attenuation in the lateral chamber wall. we have chosen to use the Monte Carlo approach instead because it is available and relatively easy to do, and because it demonstrates the utility of the EGS code to the PEP community. 13 refs., 8 figs., 3 tabs