Report on the workshop on ion sources for hadron colliders

A workshop on Ion Sources for Hadron Colliders was held September 4--5, 1997 in Gelnhausen, Germany. This workshop, organized by the WE-Heraeus-Stiftung Foundation, the University of Frankfurt, Brookhaven National Laboratory, and CERN, directly followed the 7th Symposium on Electron Beam Ion Sources and Traps. Various options were reviewed for the development of a high current, intermediate charge state heavy ion source for use on colliders such as RHIC and LHC. In addition to status reports on ECR, EBIS, and laser sources, there was also discussion of issues relevant to the scaling of these sources to intensities as required by RHIC and LHC. The presentations and discussions from this workshop are summarized

State of the art in polarized proton sources

Present day polarized H/sup +/ and H/sup -/ ion sources are reviewed by describing the performance of sources representative of each of the techniques being used. New ideas for producing higher intensities are then mentioned. Presently, pulsed H/sup +/-vector currents in the milliampere range, and H/sup -/-vector currents of hundreds of ..mu..A's, can be obtained

The upgrade of the Brookhaven Linac Isotope Producer (BLIP) and the BNL Linac

An upgrade project was recently completed on the 200 MeV H{sup -} linac and the Brookhaven Linac Isotope Producer (BLIP) in order to improve radioisotope production capacity and reliability. The average beam current has increased from 60 {mu}A to 150 {mu}A. The increased average current is the result of increases in peak current, from 25 mA to 37 mA, pulse repetition rate, from 5 to 7.5 Hz, and pulse width, from 500 to 530 ps. To achieve this performance the 35 keV, 750 keV and 200 MeV beam transport were improved, the RF transmission lines and RF power supplies replaced. Improvements to the linac control system, and the optics and vacuum system of the 200 MeV transport were implemented. A BLIP the target cooling system was upgraded to 35 kW and automated, the targets, and target mechanical systems replaced with a more robust design, and the control system upgraded. With these enhancements BLIP is ready to address the lack of availability of accelerator produced medical and research isotopes

Optics modification of the electron collector for the Relativistic Heavy Ion Collider Electron Beam Ion Source

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Overcoming weak intrinsic depolarizing resonances with energy-jump

In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. Polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. However, significant amount of polarization was lost at 0+{nu}{sub y}, 12+{nu}{sub y} and 36+{nu}{sub y}, which is believed to be partially due to the coupling resonances. To overcome the coupling resonance, an energy-jump was generated by rapidly changing the beam circumference using the powerful AGS rf system. It clearly demonstrates that the novel energy-jump method can successfully overcome coupling resonances and weak intrinsic resonances

Polarized proton experiment in the AGS with a partial snake

In three polarized proton runs at the AGS it was recently shown that the imperfection depolarizing resonances in the AGS can be overcome with a 5% partial snake and the intrinsic depolarizing resonances could be jumped with the pulsed tune-jump quadrupoles even in the presence of the partial snake. For the first time polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. No polarization was lost due to the imperfection resonances and the depolarization from most intrinsic resonances was avoided with the tune-jump quadrupoles. However, significant amount of polarization was lost at 0+{nu}{sub y}, 12+{nu}{sub y} and 36+{nu}{sub y}, which is believed to be partially due to coupling resonances. A novel energy-jump method and other new schemes to overcome the coupling and intrinsic resonances are discussed

Upgrade of the Brookhaven 200 MeV linac

The Brookhaven 200 MeV linac serves as the injector for the AGS Booster, as well as delivering beam to the Biomedical Isotope Resource Center. During the past year, many linac systems have been upgraded to allow operation at 2.5 times higher average current (150 {mu}A). This was achieved by an increase in rep-rate from 5 to 7.5 Hz, an increase in beam current from 25 mA to 37 mA, and a slight increase in pulse width to {approximately}530 {mu}s. Additional upgrades were made to improve reliability and modernize old systems. This paper describes improvements made in the 35 keV and 750 keV beam transport, 200 MeV beam transport, rf transmission line, rf power supplies, control systems, and instrumentation

Achromat with linear space charge for bunched beams

The standard definition for an achromat is a transport line having zero values for the spatial dispersion (R16) and the angular dispersion (RZ6). For a bunched beam with linear space charge this definition of achromaticity does not hold. The linear space charge in the presence of a bend provides coupling between (a) bunch spatial width and bunch length (R1.5) and (b) bunch angular spread and bunch length (R25). Therefore, achromaticity should be redefined as a line having zero values of the spatial dispersion (R16), the angular dispersion (R26), and matrix elements R15 and R25. These additional conditions (R15=R25=0) can be achieved, for example, with two small RF cavities at appropriate locations in the achromat, to cancel space charge effects. An example of the application of this technique to the Spallation Neutron Source (SNS) high energy beam transport line is presented

A new optical design for the BNL isotope production transport line

The 200 MeV linac at BNL has recently been upgraded. As a result, 2.5 times more average beam current can be delivered to the Brookhaven Isotope Resource Center (BIRC), formerly called BLIP, a facility which produces radionuclides and radiopharmaceutical for the medical community, and also supports a research program seeking more effective diagnostic and therapeutic agents. The optics of the beam transport line to BIRC was redesigned to (a) reduce transverse fluctuations of the beam at the target due to any linac energy fluctuations, (b) produce a flat beam distribution at the target, in order to avoid melting certain target materials, and (c) handle the higher beam intensity while keeping radiation levels low. A profile monitor was also modified to monitor the flatness of the beam using the algebraic reconstruction technique (ART). The above improvements will be described, and results of the commissioning of the line during the 1996 running period will be discussed

Ring magnetron ionizer

A ring magnetron D/sup -/ charge exchange ionizer has been built and tested. An H/sup -/ current of 500 ..mu..A was extracted with an estimated H/sup 0/ density in the ionizer of 10/sup 12/ cm/sup -3/. This exceeds the performance of ionizers presently in use on polarized H/sup -/ sources. The ionizer will soon be tested with a polarized atomic beam