NAPAC2019 - Table of Session: THZBB (Thursday Parallel Session 6)

Paper	Title	Page
THZBB1	Commissioning of the FRIB Beam Instrumentation
	S.M. Lidia FRIB, East Lansing, Michigan, USA
	A large variety of beam instrumentation have been developed, installed and commissioned. This talk will present various aspects of physics and engineering of beam instrumentation devices and their performance during the beam commissioning.
	Slides THZBB1 [20.535 MB]
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THZBB2	Single-Shot Wakefield Measurement System
	Q. Gao TUB, Beijing, People’s Republic of China
	A new experimental technique for the accurate measurements of wakefields is presented. Knowledge of wakefields is required for many applications ranging from the suppression of wakefields that arise from geometrical discontinuities to the enhancement of wakefields in structure and plasma based wakefield accelerators. In the past, direct measurements of wakefields were done with the drive-witness technique wherein the delay of a short witness beam trailing collinearly behind a high-charge drive beam is scanned over multiple shots and the wakefield is inferred from the energy spectrum of the witness beam. That technique is limited by shot-to-shot jitter, overlap of the drive and witness energy spectrum and the loss of all time-domain information. In this paper, we describe a new technique that overcomes these limitations by measuring the longitudinal phase space of a long witness beam and the drive beam in a single shot. We conclude by presenting experimental results to demonstrate its feasibility using a dielectric structure wakefield accelerator.
	Slides THZBB2 [4.073 MB]
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THZBB3	Novel Emittance Measurement Combining Foil Focusing and Pepper-Pot Techniques	961
	K.A. Schultz, G.T. Ortiz, M.E. Schulze LANL, Los Alamos, New Mexico, USA C. Carlson, D. Guerrero NSTec, Los Alamos, New Mexico, USA
	Funding: Work supported by the US National Nuclear Security Agency and the US Department of Energy under contract DE-AC52-06NA25396. In this paper, we describe a direct measurement of foil focusing of an intense, relativistic electron beam com-bined with the pepper-pot technique to perform emit-tance measurements. Foil focusing occurs when a thin, grounded, conducting foil shorts out the radial electric field of a transiting electron beam, causing its self-magnetic field to focus the beam. A 40-ns pulse was extracted from the main pulse of the 16-MeV, 1.65 kA beam from Axis-II of the Dual Axis Radiographic Hy-drodynamic Test Facility to perform the measurements. We show that not accounting for foil focusing signifi-cantly reduces the measured emittance.
	Slides THZBB3 [5.382 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB3
About •	paper received ※ 27 August 2019 paper accepted ※ 15 September 2019 issue date ※ 08 October 2019
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THZBB4	Beam Loss in the First Segment of the FRIB Linac	965
TUPLE17	use link to see paper's listing under its alternate paper code
	R. Shane, S. Cogan, S.M. Lidia, T. Maruta FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. Beam loss in accelerators is an unavoidable and often unwanted reality, but it is not without its use. Information from beam loss can be leveraged to optimize the tune and improve beam quality, in addition to monitoring for machine fault and failure conditions. The folded geometry at the Facility for Rare Isotope Beams (FRIB) presents a unique challenge in the detection of radiative losses, resulting in the introduction of non-traditional measurement schemes. In addition to neutron detectors and pressurized ionization chambers, FRIB will utilize halo ring monitors, fast thermometry within the cryomodules, and differential beam-current measurements. This paper will present an analysis of beam-loss measurements from commissioning the first segment of the FRIB accelerator, and a discussion of ways to evaluate and monitor the health of the beam loss monitoring system.
	Slides THZBB4 [2.477 MB]
	Poster THZBB4 [0.584 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB4
About •	paper received ※ 04 September 2019 paper accepted ※ 17 November 2020 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THZBB5	Present Status and Upgrades of the SNS Ion Beam Bunch Shape Monitors	968
	V. Tzoganis, A.V. Aleksandrov, R.W. Dickson ORNL, Oak Ridge, Tennessee, USA
	Six interceptive Feschenko-style longitudinal bunch profile monitors have been deployed in the normal conducting part of the SNS linac and HEBT. They have been operational for more than 10 years and although their performance has been satisfactory, reliability and parts obsolescence must be addressed. The upgrade plan focuses in mainly two areas, electronics architecture modernization and improvement of measurement resolution. In the first phase that is presented here the objective is to improve the control and readout electronics taking advantage of more recent technology. This will primarily address the obsolescence issues with older components, the frequent RF power failures, the non-trivial maintenance and troubleshooting and will lead to a simpler and more reliable system. This contribution describes in detail the implemented upgrades and presents the first experimental data.
	Slides THZBB5 [4.926 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB5
About •	paper received ※ 29 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THZBB6	Error Minimization in Transverse Phase-Space Measurements Using Quadrupole and Solenoid Scans	971
SUPLO03	use link to see paper's listing under its alternate paper code
TUPLE18	use link to see paper's listing under its alternate paper code
	C.Y. Wong NSCL, East Lansing, Michigan, USA S.M. Lund FRIB, East Lansing, Michigan, USA
	Quadrupole and solenoid scans are common techniques where a series of beam profile measurements are taken under varying excitation of the linear focusing elements to unfold second-order phase-space moments of the beam at an upstream location. Accurate knowledge of the moments is crucial to machine tuning and understanding the underlying beam dynamics. The scans have many sources of errors including measurement errors, field errors and misalignments. The impact of these uncertainties on the moment measurement is often not analyzed. This study proposes a scheme motivated by linear algebra error bounds that can efficiently select a set of scan parameters to minimize the errors in measured initial moments. The results are verified via a statistical error analysis. These techniques are being applied at the Facility for Rare Isotope Beams (FRIB). We find that errors in initial moments can be large under conventional scans but are greatly reduced using the procedures described.
	Slides THZBB6 [2.153 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB6
About •	paper received ※ 04 September 2019 paper accepted ※ 04 December 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

THZBB1

Commissioning of the FRIB Beam Instrumentation

S.M. Lidia
FRIB, East Lansing, Michigan, USA

A large variety of beam instrumentation have been developed, installed and commissioned. This talk will present various aspects of physics and engineering of beam instrumentation devices and their performance during the beam commissioning.

Slides THZBB1 [20.535 MB]

Export •

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

THZBB2

Single-Shot Wakefield Measurement System

Q. Gao
TUB, Beijing, People’s Republic of China

A new experimental technique for the accurate measurements of wakefields is presented. Knowledge of wakefields is required for many applications ranging from the suppression of wakefields that arise from geometrical discontinuities to the enhancement of wakefields in structure and plasma based wakefield accelerators. In the past, direct measurements of wakefields were done with the drive-witness technique wherein the delay of a short witness beam trailing collinearly behind a high-charge drive beam is scanned over multiple shots and the wakefield is inferred from the energy spectrum of the witness beam. That technique is limited by shot-to-shot jitter, overlap of the drive and witness energy spectrum and the loss of all time-domain information. In this paper, we describe a new technique that overcomes these limitations by measuring the longitudinal phase space of a long witness beam and the drive beam in a single shot. We conclude by presenting experimental results to demonstrate its feasibility using a dielectric structure wakefield accelerator.

Slides THZBB2 [4.073 MB]

Export •

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

THZBB3

Novel Emittance Measurement Combining Foil Focusing and Pepper-Pot Techniques

961

K.A. Schultz, G.T. Ortiz, M.E. Schulze
LANL, Los Alamos, New Mexico, USA
C. Carlson, D. Guerrero
NSTec, Los Alamos, New Mexico, USA

Funding: Work supported by the US National Nuclear Security Agency and the US Department of Energy under contract DE-AC52-06NA25396.
In this paper, we describe a direct measurement of foil focusing of an intense, relativistic electron beam com-bined with the pepper-pot technique to perform emit-tance measurements. Foil focusing occurs when a thin, grounded, conducting foil shorts out the radial electric field of a transiting electron beam, causing its self-magnetic field to focus the beam. A 40-ns pulse was extracted from the main pulse of the 16-MeV, 1.65 kA beam from Axis-II of the Dual Axis Radiographic Hy-drodynamic Test Facility to perform the measurements. We show that not accounting for foil focusing signifi-cantly reduces the measured emittance.

Slides THZBB3 [5.382 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB3

About •

paper received ※ 27 August 2019 paper accepted ※ 15 September 2019 issue date ※ 08 October 2019

Export •

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

THZBB4

Beam Loss in the First Segment of the FRIB Linac

965

TUPLE17

use link to see paper's listing under its alternate paper code

R. Shane, S. Cogan, S.M. Lidia, T. Maruta
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
Beam loss in accelerators is an unavoidable and often unwanted reality, but it is not without its use. Information from beam loss can be leveraged to optimize the tune and improve beam quality, in addition to monitoring for machine fault and failure conditions. The folded geometry at the Facility for Rare Isotope Beams (FRIB) presents a unique challenge in the detection of radiative losses, resulting in the introduction of non-traditional measurement schemes. In addition to neutron detectors and pressurized ionization chambers, FRIB will utilize halo ring monitors, fast thermometry within the cryomodules, and differential beam-current measurements. This paper will present an analysis of beam-loss measurements from commissioning the first segment of the FRIB accelerator, and a discussion of ways to evaluate and monitor the health of the beam loss monitoring system.

Slides THZBB4 [2.477 MB]

Poster THZBB4 [0.584 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB4

About •

paper received ※ 04 September 2019 paper accepted ※ 17 November 2020 issue date ※ 08 October 2019

Export •

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

THZBB5

Present Status and Upgrades of the SNS Ion Beam Bunch Shape Monitors

968

V. Tzoganis, A.V. Aleksandrov, R.W. Dickson
ORNL, Oak Ridge, Tennessee, USA

Six interceptive Feschenko-style longitudinal bunch profile monitors have been deployed in the normal conducting part of the SNS linac and HEBT. They have been operational for more than 10 years and although their performance has been satisfactory, reliability and parts obsolescence must be addressed. The upgrade plan focuses in mainly two areas, electronics architecture modernization and improvement of measurement resolution. In the first phase that is presented here the objective is to improve the control and readout electronics taking advantage of more recent technology. This will primarily address the obsolescence issues with older components, the frequent RF power failures, the non-trivial maintenance and troubleshooting and will lead to a simpler and more reliable system. This contribution describes in detail the implemented upgrades and presents the first experimental data.

Slides THZBB5 [4.926 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB5

About •

paper received ※ 29 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

Export •

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

THZBB6

Error Minimization in Transverse Phase-Space Measurements Using Quadrupole and Solenoid Scans

971

SUPLO03

use link to see paper's listing under its alternate paper code

TUPLE18

use link to see paper's listing under its alternate paper code

C.Y. Wong
NSCL, East Lansing, Michigan, USA
S.M. Lund
FRIB, East Lansing, Michigan, USA

Quadrupole and solenoid scans are common techniques where a series of beam profile measurements are taken under varying excitation of the linear focusing elements to unfold second-order phase-space moments of the beam at an upstream location. Accurate knowledge of the moments is crucial to machine tuning and understanding the underlying beam dynamics. The scans have many sources of errors including measurement errors, field errors and misalignments. The impact of these uncertainties on the moment measurement is often not analyzed. This study proposes a scheme motivated by linear algebra error bounds that can efficiently select a set of scan parameters to minimize the errors in measured initial moments. The results are verified via a statistical error analysis. These techniques are being applied at the Facility for Rare Isotope Beams (FRIB). We find that errors in initial moments can be large under conventional scans but are greatly reduced using the procedures described.

Slides THZBB6 [2.153 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBB6

About •

paper received ※ 04 September 2019 paper accepted ※ 04 December 2019 issue date ※ 08 October 2019

Export •

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