Comparisons Between Modeling and Measured Performance of the BNL Linac

Quite good agreement has been achieved between computer modeling and actual performance of the Brookhaven 200 MeV Linac. We will present comparisons between calculated and measured performance for the beam transport through the RFQ, the 6 meter transport from RFQ to the linac and meching and transport through the linac.Comment: 3 page

Sona transition studies in the RHIC OPPIS.

In Optically Pumped Polarized Ion Sources (OPPIS), the atomic beam is first electron polarized, and then this polarization is transferred to the nucleus by a suitable perturbing magnetic field. In the BNL OPPIS, the electron polarized atomic beam experiences the perturbing field when it traverses a region where the axial magnetic field reverses direction in a controlled manner, strength and gradient. This is the so-called Sona Transition region, named after P. G. Sona, who fist suggested the technique. We have extensively studied how the magnetic field profile in the Sona region affects beam polarization. In these studies, we have observed oscillations in polarization for certain field profiles, and tried to explain them. We report on these studies

Considerations in using third order focusing of proton beams for uniform irradiation of extended targets

The latest target designs for the National Spallation Neutron Source (NSNS) and Accelerator Production of Tritium (APT), require that the geometrical target cross-section (normal to the proton beam direction) be of rectangular shape with dimensions (10 cm x 30 cm) and (16 cm x 160 cm) for the NSNS and APT targets, respectively. These targets are to be irradiated with high-intensity proton beams. At present, plans are to use beam-expanded uniform intensities for the APT target, with possibly a small horizontal and vertical jitter superimposed. Although current plans for the NSNS target call for non expanded gaussian distributions, the authors nevertheless investigate the application of a beam expander to provide beam on that target. The high aspect ratios, 3:1 and 1:10, currently proposed for the NSNS and APT targets prompt a feasibility study for the creation of uniform beams over such targets. This paper presents a beam-optics design of two proposed beam expanders which will generate a beam to irradiate uniformly the NSNS and APT targets. Both beam optics designs are representative only, and independent of any other official designs that may exist within the design groups of the APT or NSNS project. Recent experimental work on uniform beam profiles on the target of the Brookhaven Isotope Resource Center (BIRC) of the BNL-200 MeV-LINAC will also be presented

Measurement of the analyzing power in pp elastic scattering in the peak CNI region at RHIC

We report the first measurements of the A_N absolute value and shape in the -t range from 0.0015 to 0.010GeV/c^2 with a precision better than 0.005 for each A_N data point using a polarized atomic hydrogen gas jet target and the 100 GeV RHIC proton beam.Comment: 4 pages, 5 figure

Generalized emittance measurements in a beam transport line

Motivated by the need to commission 3 beam transport lines for the new AGS Booster project, we have developed a generalized emittance-measurement program; beam line specifics are entirely resident in data tables, not in program code. For instrumentation, the program requires one or more multi-wire profile monitors; one or multiple profiles are acquired from each monitor, corresponding to one or multiple tunes of the transport line. Emittances and Twiss parameters are calculated using generalized algorithms. The required matix descriptions of the beam optics are constructed by an on-line general beam modeling program. Design of the program, its algorithms, and initial experience with it will be described. 4 refs., 2 figs., 1 tab

Status of the AGS Polarized H- Source

Development of a polarized H/sup -/ source for the AGS polarized proton project, initially begun at Argonne National Laboratory in 1979, has been continuing at Brookhaven National Laboratory since early 1982. A description of the source is given and the status of the project is reviewed

TOWARDS 100% POLARIZATION IN THE OPTICALLY-PUMPED POLARIZED ION SOURCE.

The depolarization factors in the multi-step spin-transfer polarization technique and basic limitations on maximum polarization in the OPPIS (Optically-Pumped Polarized H{sup -} Ion Source) are discussed. Detailed studies of polarization losses in the RHIC OPPIS and the source parameters optimization resulted in the OPPIS polarization increase to 86-90%. This contributed to increasing polarization in the AGS and RHIC to 65-70%

The RHIC Optically-Pumped Polarized H Ion Source.

The depolarization factors in the multi-step spin-transfer polarization technique and basic limitations on maximum polarization in the OPPIS (Optically-Pumped Polarized H{sup -} Ion Source) are discussed. Detailed studies of polarization losses in the RHIC OPPIS and the source parameters optimization resulted in the OPPIS polarization increase to 86-90%. This contributed to increasing polarization in the AGS and RHIC to 65-70%

The BNL EBIS Program: Status and plans

Recently an Electron Beam Ion Source (EBIS), on long term loan from Sandia National Laboratories, has been put into operation at Brookhaven National Laboratory. This source is being primarily used as a test device to answer questions relevant to the eventual design of an EBIS-based heavy ion preinjector for RHIC; a secondary objective is to determine parameters of an EBIS capable of delivering fully stripped light ions up to neon for medical applications. Such a source can easily produce all ions in charge states as needed, but the challenge lies in reaching intensities of interest to RHIC (2--3 {times} 10{sup 9} particles/pulse). The source studies are planned to address issues such as scaling of the electron beam current in stages up to 10 A, possible onset and control of instabilities, external ion injection, parametric studies of the ion yield, charge state distributions and emittance of the extracted ion beam, ion cooling in the trap, and other technical and physics issues

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