C.Y. Tan

An overview of the new test stand for H− ion sources at FNAL

A new test stand at Fermi National Accelerator Laboratory (FNAL) is being constructed to carry out experiments to develop and upgrade the present magnetron-type sources of H(-) ions of up to 80 mA at 35 keV in the context of the Proton Improvement Plan. The aim of this plan is to provide high-power proton beams for the experiments at FNAL. The technical details of the construction and layout of this test stand are presented, along with a prospective set of diagnostics to monitor the sources.

Implementation of Design Changes Towards a More Reliable, Hands-off Magnetron Ion Source

As the main

Optics Corrections with LOCO in the Fermilab Booster

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Collective Instabilities in the Tevatron Collider Run II Accelerators

ion source for the accelerator complex, magnetron ion sources have been used at Fermilab since the 1970s. At the offline test stand, new R&D is carried out to develop and upgrade the present magnetron-type sources of

Perpendicular Biased Ferrite Tuned Cavities for the Fermilab Booster

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A Novel Low Energy Fast Chopper for H- Injectors

ions of up to 80 mA and 35 keV beam energy in the context of the Proton Improvement Plan. The aim of this plan is to provide high-power proton beams for the experiments at FNAL. In order to reduce the amount of tuning and monitoring of these ion sources, a new electronic system consisting of a current-regulated arc discharge modulator allow the ion source to run at a constant arc current for improved beam output and operation. A solenoid-type gas valve feeds

BUCKET SHAKING STOPS BUNCH DANCING IN TEVATRON

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An Improved Retarding Field Analyzer for Electron Cloud Studies

gas into the source precisely and independently of ambient temperature. This summary will cover several studies and design changes that have been tested and will eventually be implemented on the operational magnetron sources at Fermilab. Innovative results for this type of ion source include cathode geometries, solenoid gas valves, current controlled arc pulser, cesium boiler redesign, gas mixtures of hydrogen and nitrogen, and duty factor reduction, with the aim to improve source lifetime, stability, and reducing the amount of tuning needed. In this summary, I will highlight the advances made in ion sources at Fermilab and will outline the directions of the continuing R&D effort.

Design of a Perpendicular Biased 2nd Harmonic Cavity for the Fermilab Booster

The optics of the Fermilab Booster has been corrected with LOCO (Linear Optics from Closed Orbits). However, the first corrections did not show any improvement in capture efficiency at injection. A detailed analysis of the results showed that the problem lay in the MADX optics file. Both the quadrupole and chromatic strengths were originally set as constants independent of beam energy. However, careful comparison between the measured and calculated tunes and chromatcity show that these strengths are energy dependent. After the MADX model was modified with these new energy dependent strengths, the LOCO corrected lattice has been applied to Booster. The effect of the corrected lattice will be discussed here.

Hydrogen and Cesium Monitor for H⁻ Magnetron Sources

High luminosity operation of the Tevatron during Collider Run II required high beam intensities all over the accelerator complex, and as a result, five out of six rings (except the Debuncher) had notable problems with beam stability. The instabilities of almost every type are present there: single and multibunch, transverse and longitudinal, due to electromagnetic interaction with vacuum chamber and due to interaction with ions stored in the beam, in proton and antiproton beams. In many cases, various methods to suppress the instabilities have been implemented, including various damping systems—see Table 5.1. The most severe issues with serious impact on operations were related to transverse head-tail instability in the Tevatron, transverse beam instability in the Booster, instabilities in the Recycler antiproton beams, and longitudinal instabilities in the Tevatron.