[en] Beam-orbit studies were performed for the conversion of the SREL synchrocyclotron magnet for use as a room temperature, multiparticle, isochronous cyclotron. Based on model magnet measurements of field profiles for 8 to 23⁰K gauss hill fields, a four sector spiral pole tip design has been realized which allows all isotope species of heavy ion beams to be accelerated to required final energies. The total spiral angle of 38⁰ allows injection of the beams from the MP tandem into the cyclotron through a valley. The two valey RF system of 140 kV peak accelerates beams on harmonic numbers 2, 3, 4, 6 and 10 at 14 to 21 MHz. Computer calculations indicated acceptable ν/sub z/, ν/sub r/ and phase space beam characteristics and passing of resonances for typical beams considered: ¹⁶O at 8 and 150 MeV/amu, ⁶⁰Ni at 100 MeV/amu and ²³⁸U at 2.5 and 16 MeV/amu. Single turn extraction is achieved with electrostatic deflection

[en] The (ß,π^+-) studies planned for the BNL Gamma Ray Beam Facility necessitate the detection of charged pions in the energy range 25 < T_pi < 150 MeV with a modest resolving power to match the photon beam energy resolution (27 MeV). The solid angle must be as large as possible, and the total path length must be as short as possible to minimize the losses due to pion decay. (The mean lifetime corresponds to L = 4.87 m for T_pi = 25 MeV). Finally, a means must be provided to reject pion decay products reaching the focal plane. A design for such a charged-pion spectrometer is presented. This design utilizes existing large aperture magnetic elements, and provides a momentum resolution of 0.68% at a solid angle of 50 msr, over a momentum range of 10%

[en] A spectrometer has been designed to momentum analyze electrons, from the 2.5 to 3.0 GeV x-ray storage ring of the National Synchrotron Light Source at Brookhaven National Laboratory, that have lost energy from the production of high energy γ-rays by Compton scattering of laser light. The electrons detected in the focal plane will provide a tag for the backscattered γ-rays, determining their energy (to 2.3 MeV), and timing. This design utilizes the fact that, due to kinematics, the Compton scattered electrons have a transverse phase space negligibly different from that of the stored beam. It is constrained by the requirement of not altering any of the existing elements of the storage ring. In particular, no structures or fields interfere with the large aperture of the storage ring that is required for loading the ring

[en] One of the first experimental programs to be carried out with the BNL Gamma Ray Beam will be a study of (ß,π₀). We present here a discussion of existing π₀ spectrometers and two new designs which, for the π₀ energy range of interest for this program, are superior to existing designs

[en] A new design has been developed for shaping pole tips to produce the radially increasing fields required for isochronous cyclotrons. The conventional solid hill poles are replaced by poles mounted over a small secondary gap which tapers radially from maximum at the magnet edge to zero near the center. Field measurements with a model magnet and calculations with the code TRIM show an increase in field at the edge of the magnet without the usual corresponding large increase in fringing, and a radial field shape more nearly field independent than for conventional hills. The flying hills have several advantages for variable energy multiparticle cyclotrons: (1) a large reduction in the power dissipated by isochronizing trim coils; (2) a more constant shape and magnitude flutter factor, eliminating flutter coils and increasing the operating range; and (3) a sharper fall-off of the fringe field, simplifying beam extraction

[en] Collisions of light photons with relativistic electrons have previously been used to produce polarized ß-ray beams with modest (-10%) resolution but relatively low intensity. In contrast, the LEGS project (Laser + Electron Gamma Source) at Brookhaven will produce a very high flux (>2 x 10₇ s^-₁) of background-free polarized ß rays whose energy will be determined to a high accuracy (δE = 2.3 MeV). Initially, 300(420)-MeV ß rays will be produced by backscattering uv light from the new 2.5(3.0)-GeV X-ray storage ring of the National Synchrotron Light Source (NSLS). The LEGS facility will operate as one of many passive users of the NSLS. In a later stage of the project, a Free Electron Laser is expectred to extend the ß-ray energy up to 700 MeV

[en] Within the next year we hope to begin the construction of a facility that would provide intense beams of monochromatic and polarized photons with energies in the range of several hundreds of MeV. These ν rays will be produced by Compton backscattering laser light from the electrons circulating in the 2.5 to 3.0 GeV X-RAY storage ring of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. Gamma rays up to 80 MeV in energy are produced by this mechanism at the LADON facility at Frascati. However, the techniques that will be used at Brookhaven to produce monoenergetic polarized ν-ray beams are fundamentally different than those employed at Frascati. In this paper we summarize the essential aspects and phases of development of the BNL facility

[en] The excitation functions of elastic scattering at 180⁰ for ¹⁶O + ⁴⁰Ca and ¹²C + ⁴⁰Ca are observed to oscillate between sigma/sigmasub(R) = 10^-3 and 10^-4 over a wide range of energies; the ¹⁶O + ⁵⁸Ni system shows a monotonic decrease to a value of sigma/sigmasub(R) = 10^-5 over the energy range studied. (Auth.)

[en] Beam-orbit studies were performed for the conversion of the SREL synchrocyclotron magnet for use as a room temperature, multiparticle, isochronous cyclotron. Based on model magnet measurements of field profiles for 8 to 23 K gauss hill fields, a four sector spiral pole tip design has been realized which allows all isotope species of heavy ion beams to be accelerated to required final energies. The total spiral angle of 38₀ allows injection of the beams from the MP tandem into the cyclotron through a valley. The two valley RF system of 140 kV peak accelerates beams on harmonic numbers 2, 3, 4, 6 and 10 at 14 to 21 MHz. Computer calculations indicated acceptable nu_z, nu_r and phase space beam characteristics and passing of resonances for typical beams considered: ₁₆O at 8 and 150 MeV/amu, ₆₀Ni at 100 MeV/amu; and ₂₃₈U at 2.5 and 16 MeV/amu. Single turn extraction is achieved with electrostatic deflection. 4 figures

[en] A new design has been developed for shaping pole tips to produce the radially increasing fields required for isochronous cyclotrons. The conventional solid hillpoles are replaced by poles mounted over a small secondary gap which tapers radially from maximum at the magnet edge to zero near the center. Field measurements with a model magnet and calculations with the code TRIM show an increase in field at the edge of the magnet without the usual corresponding large increase in fringing, and a radial field shape more nearly field independent than for conventional hills. The flying hills have several advantages for variable energy multiparticle cyclotrons: (1) a large reduction in the power dissipated by isochronizing trim coils; (2) a more constant shape and magnitude flutter factor, eliminating flutter coils and increasing the operating range; and (3) a sharper fall-off of the fringe field, simplifying beam extraction. 6 figures