Design study of a normal conducting helical snake for AGS
A new normal conducting snake magnet is being fabricated for the alternate gradient synchrotron (AGS) at Brookhaven National Laboratory (BNL). In the Relativistic Heavy Ion Collider (RHIC) project, a superconducting type helical dipole magnets had been developed and it performed successfully in high-energy polarized proton acceleration. The new AGS helical snake has the same basic magnetic structure but is more complicated. To achieve no beam shift and no beam deflection in one magnetic device, helical pitches and rotating angles were carefully calculated. Compared to a superconducting magnet, a normal warm magnet must have a large cross-sectional area of conductors which make it difficult to design a magnet with large helical pitch. We developed a modified window frame structure to accommodate the large number of conductors. Its three dimensional magnetic field was simulated by using OPERA3D/TOSCA.
DESIGN STUDY OF A PARTIAL SNAKE FOR THE AGS
A superconducting helical dipole magnet, which will help preserve the polarization of a proton beam in the Alternate Gradient Synchrotron (AGS), has been proposed. Replacing an existing solenoid type Siberian Snake with the helical magnet, the strength of the remaining intrinsic resonances, which are due to transverse coupling, can be reduced. This magnet has a field of 3 T and an effective length of 2 m. Field shape and multipole components obtained by 3D field calculations are discussed. Also, the cooling system for this magnet is studied.
Construction of helical magnets for RHIC
Helical magnets are required in RHIC to control proton spin in a program for polarized proton colliding beam experiments. The basic construction unit is superconducting magnet producing a four tesla dipole field that rotates through 360 degrees in a length of 2.4 meters. These magnets are assembled in groups of four to build four Snakes to control spin in the lattice and eight Rotators to orient spin at two collision points. A collaboration with the Japanese institute RIKEN is providing financial support to carry out the program. After a successful R&D program to validate the design, the magnets are in the construction phase. The design of the magnets is reviewed, the construction approach is described, and test results from the first completed units are presented.