R. J. Lari

Edge-Cooled, High-Current Septum Magnet

The resonant extraction system of the Zero Gradient Synchrotron (ZGS) includes a thin septum magnet with a two-turn winding having a total thickness of 0.06 in. The gap height is two in and the length is 20 in. This magnet is excited with currents as high as 7000 A (current density of 130,000 A/in2 to produce a field of 3.5 kG across the gap. Simplicity in design has been used extensively in the building of the core and the winding, resulting in an operation life test of one year to date. This magnet is used in a pulsed mode with a rise time of less than 100 ms and pulses up to 0. 8 s in length for slow spills. All portions of the design and fabrication are accomplished by taking advantage of commercially available materials and metals and no sophisticated machining practices were used in making this type of magnet. This paper describes the computer design, the construction practices, and the test data on pertinent parameters.

The Proton Diagnostic Accelerator

The advantage of proton radiography for early cancer detection in soft human tissue has been demonstrated. 1-4 In order for this technique to become a practical medical tool for early detection of cancer, however, a proton source suitable for use in hospitals and clinics is required. An initial concept of such an accelerator has been discussed.5 It would meet the requirements considerably better than any existing accelerator and be simple, reliable, and economical.

A Pulsed Quadrupole System for Preventing Depolarization

A pair of pulsed quadrupoles spaced 180° apart in the Zero Gradient Synchrotron (ZGS) ring was installed to prevent the depolarization of polarized protons during acceleration in the ZGS. These quadrupoles must produce a 50-G/in gradient over a useful aperture of 2 in vertically and 10 in radially. The pulse must have a 10-?s rise time and a 2?-ms flattop. They must be pulsed up to ten times during the 1?-s ZGS acceleration period. The computer calculations and the mechanical and electrical design and fabrication of the quadrupoles and their power supply will be described.

Conceptual Design of the Argonne 6-GeV Synchrotron Light Source

The Argonne National Laboratory Synchrotron Light Source Storage Ring is designed to have a natural emittance of 6.5 × 10-9 m for circulating 6-GeV positrons. Thirty of the 32 long straight sections, each 6.5-m long, will be available for synchrotron light insertion devices. A circulating positron current of 300 mA can be injected in about 8 min. from a booster synchrotron operating with a repetition time of 1.2 sec. The booster synchrotron will contain two different rf systems. The lower frequency system (38.97 MHz) will accept positrons from a 360-MeV linac and will accelerate them to 2.25 GeV. The higher frequency system (350.76 MHz) will accelerate the positrons to 6 GeV. The positrons will be produced from a 300-MeV electron beam on a tungsten target. A conceptual layout is shown in Fig. 1. Related papers on the Argonne Synchrotron Light Source may be found in references 1-3.

Field Properties for a 4-GeV Microtron Sector Magnet

The central magnetic field uniformity and field edge shapes have been investigated for a 609 metric ton sector magnet designed for the 4 GeV Electron Microtron (GEM) at Argonne National Laboratory. The effect of a Purcell filter on the central field uniformity was studied using the 2D magnetostatic computer program, TRIM. The effects on the shape of the edge field were studied for various geometries of endguard, pole tip shim, shield plate, pole edge shape, and coil. Both 2D and 3D programs were used for these latter studies and all results showed that the proposed design would produce acceptable field qualities.

Field Design of the Main-Ring Bending Magnets of the NAL 200-GeV Synchrotron

Two types of bending magnets are used to match the beam width in the separated-function FODO lattice of the main ring of the NAL 200-GeV accelerator. Bending magnet B1 has an aperture of 5 in × 1.5 in, an overall dimension of 25 in × 16 in and a 12-turn coil; bending magnet B2 has an aperture of 4 in × 2 in, an overall dimension of 25 in × 14 in, and a 16-turn coil. With proper geometry and a small amount of pole-face crenellation, the good-field regions of these magnets extend over ~80% qf the aperture to beyond 20 kG. At 18 kG which corresponds to 400 GeV the saturation is only 3.7% and the excitation current is 4746 A. The magnetic -field design is performed using computer program TRIM. The factors of consideration and techniques involved in the design will be discussed.

The Design of the Zero Gradient Synchrotron Booster II Ring Magnet

The booster program was undertaken at the Argonne National Laboratory Zero Gradient Synchrotron (ZGS) to increase the ZGS beam intensity. By using the transplanted Cornell University 2. 2 GeV synchrotron as Booster I, it has been shown at the ZGS that more than one hundred turns of Hions can be injected and stripped to H+ in a booster ring. In Booster II, this intense beam can be accelerated to 500 MeV. Several pulses from the booster, which can run at 60 Hz, will make one ZGS pulse. The Booster II ring magnet is now under construction.