[en] This report discusses the program goals, development lab, tests of charge recovery efficiency, plans and schedules, and other issues of the Fermilab electron cooling R ampersand D project

[en] ESME is a computer program to calculate the evolution of a distribution of particles in energy and azimuth as it is acted upon by the radio frequency system of a proton synchrotron. It provides for the modeling of multiple rf systems, feedback control, space charge, and many of the effects of longitudinal coupling impedance. The capabilities of the program are described, and the requirements for input data are specified in sufficient detail to permit significant calculations by an uninitiated user. The program is currently at version 8.1 and extensively modified since the previous user documentation. Changes since the 7.xx versions include a new command and associated parameters for mapping phase space flow lines, new names for a few parameters, and a few new parameters for old commands. Special attention has been given to features relating to calculation of the collective potential and the generation of phase space trajectories including its effects. The VAX-based code management convention has been modified slightly to permit pre-compile options to be used in the include files as well as the program source files. The biggest change from v. 8.0 to v. 8.1 is the addition of code for HIGZ-based graphics; the new code and that using DI3000/GRAFMAKER are alternatives selectable at compilation. Other changes relate to improved control of smoothing options in the calculation of collective potential, fourier spectra, and mountain range plots

[en] A long-established technique for accumulating high current in a storage ring is to inject additional beam off-momentum and move it into the main beam stack by rf acceleration. This procedure necessarily dilutes the longitudinal phase space density, because the rf perturbs the stack as the new beam approaches closely in momentum. For accumulators that use beam cooling to obtain a high phase space density, this perturbation may result in an unacceptable performance limitation. Using broadband rf to establish and manipulate azimuthal barriers to the motion of the stack and injected beam permits practically dilution-free longitudinal phase space stacking. The concept is described and illustrated with a detailed example which pertains to the Fermilab Recycler ring

[en] ESME is a computer program to calculate the evolution of a distribution of particles in energy and azimuth as it is acted upon by the radiofrequency system of a proton synchrotron. It provides for the modeling of multiple rf systems, feedback control, spacecharge, and many of the effects of longitudinal coupling impedance. The capabilities of the program are described, and the requirements for input data are specified in sufficient detail to permit significant calculations by an uninitiated user. The program is currently at version 7.1 and extensively modified since the previous user documentation. Fundamental enhancements make version 6 data unusable, but nearly all facilities of the earlier version have been retained and input data is similar. Also described is a VAX-based code management convention which has been established with a view to maintaining functional equivalence in versions used on different computers. 13 refs

[en] We describe a technique for generating narrow proton bunches for anti p production without counterphasing the Main Ring rf. This procedure is apparently as effective as the previously proposed procedure and it offers several advantages. 5 figures

[en] MEEC96 was a workshop devoted primarily to discussion within four working groups, not a mini-conference of prepared reports. Therefore, although there are contributions bearing the name of a single author, much of what was learned came in extemporaneous discussion of the issues posed to the participants. The original plan to produce formal proceedings has been dropped because of the limited number of participants willing to write up their own contributions and because of the difficulty of converting free-wheeling discussion to the written word. The premsise for the 1996 gathering was to set a critique of Fermilab''s R ampersand D effort at cooling a ring of 8 GeV bar p''s. Separate abstracts have been submitted to the energy database for contributions to this workshop

[en] The longitudinal phase space program ESME, modified for space charge and wall impedance effects, has been used to simulate transition crossing in the Fermilab Booster. The simulations yield results in reasonable quantitative agreement with measured parameters. They further indicate that a transition jump scheme currently under construction will significantly reduce emittance growth, while attempts to alter machine impedance are less obviously beneficial. In addition to presenting results, this paper points out a serious difficulty, related to statistical fluctuations, in the space charge calculation. False indications of emittance growth can appear if care is not taken to minimize this problem

[en] ESME is a program developed at Fermilab for simulating both single particle and multi-particle dynamics in proton synchrotrons. The code has evolved incrementally for more than fifteen years, accumulating many useful features and some internal inconsistency in the process. In the latest revision (8.2), a significant effort has been made to eliminate inconsistency and ambiguity in the determination of phases for multiple RF systems. The use of frequency and phase curves is now more transparent. Other additions or improvements include additional features for time domain calculation, low noise distributions to extend multi-particle capability, run-time memory allocation and portable graphics. A Web page has been established to facilitate the distribution of the source code and documentation. Further information, bug reports and fixes will be made available through this resource

[en] The anti p source for SSC discussed at the ANL/UC workshop assumes the possibility of reducing momentum spread from +/- 3% to +/- .25% on a 10 GeV debunching orbit. Where parameters had not been defined at the workshop, reasonable values were chosen for a proton accelerator and debuncher to check whether this expectation is realistic. These parameters have been chosen by scaling from the Fermilab design and making some conservative extrapolations from the results of accelerator experiments. The relevant parameters of the proton accelerator and the debunching orbit parameters are given

[en] A very-low-intensity bunch of protons in the Fermilab Main Ring was brought to an energy close to but below transition (frequency-dispersion factor η₀ approx-gt - 2 x 10^-5) at a front porch. The rf was turned off abruptly. The debunching was recorded in multi-trace oscillograms (''mountain-range plots'') with ∼ 20 ms delay between traces. The front-porch energy was increased in very small steps in subsequent cycles to about η₀≅ 8 x 10^-5 above transition and the debunching repeated. The transition gamma could be determined very accurately by comparing the debunching rates at different energies. We observed longitudinal spread at every energy, indicating the presence of nonlinear effects in the frequency dispersion. The second term in the momentum-offset expansion of the momentum compaction, namely α₁, was determined