[en] For future experiments at the intensity frontier precise and accurate knowledge of beam time structure will be critical to understanding backgrounds. The proposed Mu2e experiment calls for ∼ 200ns (FW, 40 ns rms) bunches of 3 x 10⁷ 8 GeV protons and a bunch spacing of 1695 ns. The interbunch beam must be suppressed from the main pulse by a factor of 10^-10, this is known as the beam extinction requirement. Beam from Fermilab's Booster will be formed into 2.5 MHz buckets in the Fermilab Recycler then transferred to the Delivery Ring (formerly the Debuncher) and slow spilled from a single filled bucket in an h = 4 RF system. Because the final extinction level is not expected from the Delivery Ring an AC dipole and collimation system will be used to achieve final extinction. Here I present calculations leading to a first estimate of the extinction level expected upon extraction from the Delivery Ring of (le) 3.36 x 10^-4. Intrabunch, residual gas scattering and scattering off the extraction septum are included. Contributions from bunch formation are not considered.

[en] The AC dipole is an oscillating dipole magnet which can induce large amplitude oscillations without the emittance growth and decoherence. These properties make it a good tool to measure optics of a hadron synchrotron. The vertical AC dipole for the Tevatron is powered by an inexpensive high power audio amplifier since its operating frequency is approximately 20 kHz. The magnet is incorporated into a parallel resonant system to maximize the current. The use of a vertical pinger magnet which has been installed in the Tevatron made the cost relatively inexpensive. Recently, the initial system was upgraded with a more powerful amplifier and oscillation amplitudes up to 2-3σ were achieved with the 980 GeV proton beam. This paper discusses details of the Tevatron AC dipole system and also shows its test results

[en] An AC dipole magnet produces a sinusoidally oscillating dipole field with frequency close to betatron frequency and excites large sustained oscillations of beam particles circulating in a synchrotron. Observation of such oscillations with beam position monitors allows direct measurements of a synchrotron's nonlinear parameters. This paper presents experimental studies to measure perturbative effects of sextupole and octupole fields, performed in the Fermilab Tevatron using an ACdipole

[en] In many accelerators, cylindrical pick-ups are used to measure transverse beam positions. Theoretically, signals from these pick-ups are related to infinite power series of the beam position but, in practice, only finite number of terms are considered and the position measurements degrade when a beam is far from the center of a pick-up. This paper shows there is actually a simple geometrical relation between a beam position and induced signals. With help of the geometrical relation, the beam position can be written in a compact function of signals. The paper is concluded with numerical simulations and a test to show this geometry based expression can calculate a beam position better than the conventional methods

[en] The CLEO e⁺e^- →Υ(4S) experiment is being upgraded in early 1998 to study CP violation in and rare decays of B mesons. The CESR e⁺e^- storage ring will be upgraded to deliver luminosities in excess of 2-5 x 10³³ cm^-2s^-1, or ∝10⁸ BB pairs in 5 years. The CLEO detector will also be upgraded to exploit this large dataset and better isolate rare B meson decays. (orig.)

[en] The AC dipole is a device to study beam optics of hadron synchrotrons. It can produce sustained large amplitude oscillations with virtually no emittance growth. A vertical AC dipole for the Tevatron is recently implemented and a maximum oscillation amplitude of 2σ (4σ) at 980 GeV (150 GeV) is achieved [1]. When such large oscillations are measured with the BPM system of the Tevatron (20 (micro)m resolution), not only linear but even nonlinear optics can be directly measured. This paper shows how to measure β function using an AC dipole and the result is compared to the other measurement. The paper also shows a test to detect optics changes when small changes are made in the Tevatron. Since an AC dipole is nondestructive, it allows frequent measurements of the optics which is necessary for such an test

[en] We present studies of helium- and argon-filled ionization chambers exposed to intense neutron fluxes from PuBe neutron sources (E_n=1-10 MeV). The sources emit about 10⁸ neutrons per second. The number of ion pairs in the chamber gas volume per incident neutron is derived. While limited in precision because of a large gamma ray background from the PuBe sources, our results are consistent with the expectation that the neutrons interact purely elastically in the chamber gas

[en] For future experiments at the intensity frontier, precise and accurate knowledge of beam time structure will be critical to understanding backgrounds. The proposed Mu2e experiment will utilize ∼200 ns (FW) bunches of 3 x 10⁷ protons at 8 GeV with a bunch-to-bunch period of 1695 ns. The out-of-bunch beam must be suppressed by a factor of 10^-10 relative to in-bunch beam and continuously monitored. I propose a Cerenkov-based particle telescope to measure secondary production from beam interactions in a several tens of microns thick foil. Correlating timing information with beam passage will allow the determination of relative beam intensity to arbitrary precision given a sufficiently long integration time. The goal is to verify out-of-bunch extinction to the level 10^-6 in the span of several seconds. This will allow near real-time monitoring of the initial extinction of the beam resonantly extracted from Fermilabs Debuncher before a system of AC dipoles and collimators, which will provide the final extinction. The effect on beam emittance is minimal, allowing the necessary continuous measurement. I will present the detector design and some concerns about bunch growth during the resonant extraction.

[en] We have calibrated the lattice model and measured the beta and dispersion functions in Fermilab's fast-ramping Booster synchrotron using the Linear Optics from Closed Orbit (LOCO) method. We used the calibrated model to implement ramped coupling, dispersion, and beta-beating corrections throughout the acceleration cycle, reducing horizontal beta beating from its initial magnitude of ∼30% to ∼10%, and essentially eliminating vertical beta-beating and transverse coupling.

[en] We have developed a new focusing system for conventional neutrino beams. The 'Hadron Hose' is a wire located in the meson decay volume, downstream of the target and focusing horns. The wire is pulsed with high current to provide a toroidal magnetic field which continuously focuses mesons. The hose increases the neutrino event rate and reduces differences between near- and far-field neutrino spectra for oscillation experiments. We have studied this device as part of the development of the Neutrinos at the Main Injector project, but it might also be of use for other conventional neutrino beams