Engineering topics

Hock, Kiel [Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000218860661)

Publications and source records attributed to Hock, Kiel [Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000218860661).

3 records

All sources NASA NTRS DOE OSTI

DOE OSTI2026

Rotators for the Hadron Storage Ring

The Electron Ion Collider calls for collisions of polarized electrons on transversely and longitudinally polarized protons and helions. To facilitate longitudinal polar ization, helical dipole rotator magnets from the Relativistic Heavy Ion Collider will be reused. These rotators are placed asymmetrically at -35.28 and 61.35 mrad from the interaction point. Longitudinal polarization of polarized protons cannot be satisfied for all energies while remaining below the maximum current of 322 A. Care has been taken to ensure longitudinal polarization can be satisfied at the energies of interest. The rotators ramping result in a shift in νs which has been compensated for with a change in the snake precession axes. The rotators can satisfy longitudinal polarization at all energies of interest, and the νs compensation has also been established.

43 PARTICLE ACCELERATORS↗

DOE OSTI2026

Improvements to Stripping Foils in BTA

To achieve the desired charge state in the Alternating Gradient Synchrotron (AGS), there is a stripping foil in the Booster to AGS (BtA) transfer line. For light ions, such as p, d, and h, they are already fully stripped in the Booster, or ions such as O have few electrons to be stripped off, and a thin foil of aluminum is used. For medium weight ions, such as Zr and Ru, they use what foils are available which have been optimized for heavy and light ions at 100 MeV/u. This worked well in the Zr case which achieved a measured stripping efficiency of 87%, contrary to the Ru case which achieved a measured stripping efficiency of 63%. For the EIC early science, Ag is currently intended to be the first ion. Using our existing foils, this would, at best, yield a helium-like charge state with a theoretical stripping efficiency of 50%. To improve on this, two foils of Ti or Nb have been selected to provide optimal stripping efficiency of Ag, and other energetic medium ions, which can reach 90% efficiency to fully strip the Ag ions. For heavy ions, the Al+C or Al+Ni stripping foils (sandwich foils) are used to produce helium-like charge states. For high intensity operation of Au, the Al foil nears its melting point and, in some cases, has been severely damaged. To maximize foil lifetime, there is a maximum intensity per unit time in BTA dependent on the Booster and AGS timing configurations. To mitigate the risk of melting the Al, replacement foils that use Ti, Nb, or anodized Al have been evaluated for their improved thermal qualities. At the selected thicknesses, each foil has equivalent charge distributions before entering the C foil, and should provide the same stripping efficiency through the entire sandwich.

43 PARTICLE ACCELERATORS↗

DOE OSTI2025

Snakes for the Hadron Storage Ring

The Electron Ion Collider calls for collisions of polarized proton and polarized helion beams on polarized electron beams. To preserve polarization of these polarized hadron beams during acceleration, six full helical snakes will be installed. As there are currently 4 snakes in RHIC, the remaining two snakes will be made from existing rotator magnet coils. The existing snakes are made from only right-handed helices where the rotator magnets are made from both right handed and left handed helicity magnets. In order for a sufficient stock of spare coils, one snake will be made of left handed coils. Simulations using Opera field maps in zgoubi show the left handed snake has sufficient range to provide the desired snake precession axes for helions and protons with the existing power supplies. This is an overview of the right and left handed snake assemblies and their effects.

43 PARTICLE ACCELERATORS↗