HB2021 - List of Authors (Evans, N.J.)

Paper	Title	Page
MOAC3	Development of an Injection-Painted Self-Consistent Beam in the Spallation Neutron Source Ring	7
	A.M. Hoover UTK, Knoxville, Tennessee, USA N.J. Evans ORNL RAD, Oak Ridge, Tennessee, USA T.V. Gorlov, J.A. Holmes ORNL, Oak Ridge, Tennessee, USA
	A self-consistent beam maintains linear space charge forces under any linear transport, even with the inclusion of space charge in the dynamics. Simulation indicates that it is possible to approximate certain self-consistent distributions in a ring with the use of phase space painting. We focus on the so-called Danilov distribution, which is a uniform density, rotating, elliptical distribution in the transverse plane and a coasting beam in the longitudinal plane. Painting the beam requires measurement and control of the orbit at the injection point, and measuring the beam requires re- construction of the four-dimensional (4D) transverse phase space. We discuss efforts to meet these requirements in the Spallation Neutron Source (SNS) ring.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2021-MOAC3
About •	Received ※ 18 October 2021 — Revised ※ 21 October 2021 — Accepted ※ 22 November 2021 — Issued ※ 02 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUEC2	Operational Experience with Nanocrystalline Injection Foils at SNS	176
	N.J. Evans ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: SNS is managed by UT-Battelle, LLC, under contract DE- AC05-00OR22725 for the U.S. Department of Energy. The Spallation Neutron Source (SNS) uses 300-400μ g/cm² nanocrystalline diamond foils grown in-house at the Center for Nanophase Materials Sciences to facilitate charge exchange injection (CEI) from the 1 GeV H⁻ linac into the 248~m circumference accumulation ring. These foils have performed exceptionally well with lifetimes of thousands of MW·hrs. This contribution shares some experience with the operation of these foils during 1.4 MW operation, and discusses current operational concerns including injection related losses, foil conditioning, deformation, and sublimation due to high temperatures. The implications for the SNS Proton Power Upgrade are also discussed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2021-TUEC2
About •	Received ※ 17 October 2021 — Revised ※ 21 October 2021 — Accepted ※ 23 November 2021 — Issued ※ 06 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Development of an Injection-Painted Self-Consistent Beam in the Spallation Neutron Source Ring

7

A.M. Hoover
UTK, Knoxville, Tennessee, USA
N.J. Evans
ORNL RAD, Oak Ridge, Tennessee, USA
T.V. Gorlov, J.A. Holmes
ORNL, Oak Ridge, Tennessee, USA

A self-consistent beam maintains linear space charge forces under any linear transport, even with the inclusion of space charge in the dynamics. Simulation indicates that it is possible to approximate certain self-consistent distributions in a ring with the use of phase space painting. We focus on the so-called Danilov distribution, which is a uniform density, rotating, elliptical distribution in the transverse plane and a coasting beam in the longitudinal plane. Painting the beam requires measurement and control of the orbit at the injection point, and measuring the beam requires re- construction of the four-dimensional (4D) transverse phase space. We discuss efforts to meet these requirements in the Spallation Neutron Source (SNS) ring.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2021-MOAC3

About •

Received ※ 18 October 2021 — Revised ※ 21 October 2021 — Accepted ※ 22 November 2021 — Issued ※ 02 March 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUEC2

Operational Experience with Nanocrystalline Injection Foils at SNS

176

N.J. Evans
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: SNS is managed by UT-Battelle, LLC, under contract DE- AC05-00OR22725 for the U.S. Department of Energy.
The Spallation Neutron Source (SNS) uses 300-400μ g/cm² nanocrystalline diamond foils grown in-house at the Center for Nanophase Materials Sciences to facilitate charge exchange injection (CEI) from the 1 GeV H⁻ linac into the 248~m circumference accumulation ring. These foils have performed exceptionally well with lifetimes of thousands of MW·hrs. This contribution shares some experience with the operation of these foils during 1.4 MW operation, and discusses current operational concerns including injection related losses, foil conditioning, deformation, and sublimation due to high temperatures. The implications for the SNS Proton Power Upgrade are also discussed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2021-TUEC2

About •

Received ※ 17 October 2021 — Revised ※ 21 October 2021 — Accepted ※ 23 November 2021 — Issued ※ 06 March 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)