IPAC2011 - List of Authors (Solyak, N.)

Paper	Title	Page
WEPS065	Segmentation in the Project-X Low Energy CW Linac Front End	2649
	J.-F. Ostiguy, B.G. Shteynas, N. Solyak Fermilab, Batavia, USA
	Funding: Fermi National Accelerator Laboratory (Fermilab) is operated by Fermi Research Alliance, LLC. for the U.S. Department of Energy under contract DE-AC02-07CH11359 The low-energy front-end of the Project-X 2.5 MeV - 3 GeV linac utilizes superconducting single-spoke resonators for acceleration and solenoids for transverse focusing. To take advantage of the available accelerating field in the cavities, it is necessary to minimize the period length. This leads to a compact arrangement of cavities and solenoids with very minimal open longitudinal space. While beam position monitors and correctors can be integrated to the solenoid assemblies inside a cryostat, some instrumentation such as beam profile monitors require dedicated warm longitudinal space. In this paper we discuss an arrangement where the front-end is segmented in crystats comprising about half a dozen lattice periods separated by a minimal amount of warm longitudinal space. We discuss the impact of introducting such openings and present an optical solution integrating them. The strategy and constraints leading to this solution are outlined.

WEPS066	Residual Focusing Asymmetry in Superconducting Spoke Cavities	2652
	J.-F. Ostiguy, N. Solyak Fermilab, Batavia, USA
	Funding: Fermi National Accelerator Laboratory (Fermilab) is operated by Fermi Research Alliance, LLC. for the U.S. Department of Energy under contract DE-AC02-07CH11359. Project-X is a proposed high intensity proton source at Fermilab. Protons (H⁻) are first accelerated from 2.5 to 3 GeV in a superconducting linac operating in CW mode. While most of the particles are delivered to a variety of precision experiments, a fraction ( about 10%) is further accelerated to 8 GeV in a second superconducting linac operating in pulsed mode. In the low energy front-end of the first stage CW linac, single-spoke cavities are used for acceleration while solenoids and quadrupole doublets provide transverse focusing. The transverse rf defocusing arising from the spoke cavities has a small residual asymmetry whose effect can become noticeable in periods where the transverse phase advance is low. In this paper we discuss this effect, its practical consequences, as well as possible mitigation strategies.

Paper

Title

Page

Segmentation in the Project-X Low Energy CW Linac Front End

2649

J.-F. Ostiguy, B.G. Shteynas, N. Solyak
Fermilab, Batavia, USA

Funding: Fermi National Accelerator Laboratory (Fermilab) is operated by Fermi Research Alliance, LLC. for the U.S. Department of Energy under contract DE-AC02-07CH11359
The low-energy front-end of the Project-X 2.5 MeV - 3 GeV linac utilizes superconducting single-spoke resonators for acceleration and solenoids for transverse focusing. To take advantage of the available accelerating field in the cavities, it is necessary to minimize the period length. This leads to a compact arrangement of cavities and solenoids with very minimal open longitudinal space. While beam position monitors and correctors can be integrated to the solenoid assemblies inside a cryostat, some instrumentation such as beam profile monitors require dedicated warm longitudinal space. In this paper we discuss an arrangement where the front-end is segmented in crystats comprising about half a dozen lattice periods separated by a minimal amount of warm longitudinal space. We discuss the impact of introducting such openings and present an optical solution integrating them. The strategy and constraints leading to this solution are outlined.

WEPS066

Residual Focusing Asymmetry in Superconducting Spoke Cavities

2652

J.-F. Ostiguy, N. Solyak
Fermilab, Batavia, USA

Funding: Fermi National Accelerator Laboratory (Fermilab) is operated by Fermi Research Alliance, LLC. for the U.S. Department of Energy under contract DE-AC02-07CH11359.
Project-X is a proposed high intensity proton source at Fermilab. Protons (H⁻) are first accelerated from 2.5 to 3 GeV in a superconducting linac operating in CW mode. While most of the particles are delivered to a variety of precision experiments, a fraction ( about 10%) is further accelerated to 8 GeV in a second superconducting linac operating in pulsed mode. In the low energy front-end of the first stage CW linac, single-spoke cavities are used for acceleration while solenoids and quadrupole doublets provide transverse focusing. The transverse rf defocusing arising from the spoke cavities has a small residual asymmetry whose effect can become noticeable in periods where the transverse phase advance is low. In this paper we discuss this effect, its practical consequences, as well as possible mitigation strategies.