ECRIS2020 - Table of Session: TUZZO (Tuesday Oral After Third Break)

Paper	Title	Page
TUZZO01	Characterization of 2.45 GHz ECR Ion Source Bench for Accelerator-Based 14-MeV Neutron Generator	95
	S.J. Vala, M. Abhangi, M. Bandyopadhyay, R. Kumar, R. Kumar Institute for Plasma Research, Bhat, Gandhinagar, India
	The 2.45 GHz Electron Cyclotron Resonance Ion Source (ECRIS) has been indigenously developed. This development of ECRIS aims to provide high brightness, stable, and reliable D⁺ ion beam of 20 mA beam current in a continuous (CW) mode operation for an accelerator-based D-T neutron generator. The ECR ion source setup consists of a microwave system, a magnet system, a double wall water-cooled plasma chamber, a high voltage platform, a three-electrode ion extraction system, and a vacuum system. The ECR ion source test setup is installed, and the deuterium plasma is generated. A three-electrode extraction system is designed and fabricated for the ion beam extraction. A ~10 mA deuterium ion beam is extracted from the ECR ion source. The paper covers the detailed experimental setup of ion beam characterization and diagnostics used for measurement of beam profile, beam current, and beam emittance measurements. It also covers the latest results of beam emittance measurements.
	Slides TUZZO01 [0.727 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO01
About •	Received ※ 29 September 2020 — Revised ※ 23 December 2020 — Accepted ※ 19 May 2021 — Issue date ※ 28 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUZZO02	Electron Cyclotron Resonance Ion Source Related Research and Development Work at the Department of Physics, University of Jyväskylä (JYFL)	98
	H.A. Koivisto, B.S. Bhaskar, A. Ikonen, T. Kalvas, S.T. Kosonen, R.J. Kronholm, M.S.P. Marttinenpresenter, O.P.I. Timonen, V. Toivanen JYFL, Jyväskylä, Finland J. Angot, B.S. Bhaskar, T. Thuillier LPSC, Grenoble Cedex, France I. Izotov, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia L. Maunoury GANIL, Caen, France O.A. Tarvainen STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project. Recent research work of the JYFL ion source team covers multi-diagnostic studies of plasma instabilities, high-resolution plasma optical emission spectroscopy, ion current transient measurements to define the total life-time of a particle in the highly charged plasma. The JYFL team also elaborates the magnetic and technical design of the unconventional ion source named CUBE. The R&D work includes, in addition, the commissioning and operation of the high-performance 18 GHz ECRIS, HIISI. The instability measurements have revealed new information about the parameters affecting the onset of the plasma instabilities and shown that different instability modes exist. The ion-beam transient studies have given information about the cumulative life-time of highly-charged ions convergent with the ion temperatures deduced from the Doppler broadening of emission lines. The CUBE prototype has a minimum-B quadrupole magnetic field topology, similar to ARC-ECRIS, and its all-permanent magnet structure has been optimized for 10 GHz frequency. The CUBE design will be presented along with its commissioning status. The status and operational experience with HIISI will be reported as well.
	Slides TUZZO02 [9.553 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO02
About •	Received ※ 28 September 2020 — Revised ※ 09 November 2020 — Accepted ※ 03 December 2020 — Issue date ※ 05 May 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUZZO03	Study on the Correlation between Energy Distribution of Electrons Lost from the Confinement and Plasma Bremsstrahlung on a min-B ECR Plasmas
	B.S. Bhaskar, T. Thuillier LPSC, Grenoble Cedex, France B.S. Bhaskar, T. Kalvas, H.A. Koivisto, R.J. Kronholm, M.S.P. Marttinen, O.A. Tarvainen, V. Toivanen JYFL, Jyväskylä, Finland I. Izotov, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia O.A. Tarvainen STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project. The study of plasma bremsstrahlung has been used as a diagnostic tool for understanding the behavior of confined plasma in Electron Cyclotron Resonance Ion Sources (ECRIS). In order to understand the relation connecting the confined plasma and the electrons escaping the confinement, a series of measurements have been made to measure the bremsstrahlung produced in the axial and radial direction along with the Lost Electron Energy Distribution (LEED) axially on JYFL 14 GHz ECR. We present here the effect of various source parameters on the axial and radial bremsstrahlung along with the LEED on a min-B confined ECR plasma. The measured LEED has been found to show a correlation with bremsstrahlung measurement and also have observed as a potential diagnostic method for instability. The explanation for observed LEED and bremsstrahlung trends is provided.
	Slides TUZZO03 [1.520 MB]
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUZZO04	Status of the 60 GHz ECR Ion Source Research	102
	T. André, J. Angot, M.A. Baylac, P. Sole, T. Thuillier LPSC, Grenoble Cedex, France F. Debray GHMFL, Grenoble, France I. Izotov, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia
	SEISM is a compact ECR ion source operating at 60 GHz developed up to 2014. The prototype uses a magnetic cusp to confine the plasma. This simple magnetic geometry was chosen to allow the use of polyhelix coils (developed at the LNCMI, Grenoble) to generate a strong magnetic confinement featuring a closed ECR surface at 2.1 T. The plasma is sustained by a 300 kW microwave pulse of 1 ms duration and with a 2 Hz repetition rate. Previous experiments at LNCMI have successfully demonstrated the establishment of the nominal magnetic field and the extraction of ion beams with a current density up to ~ 1A/cm². The presence of "afterglow" peaks was also observed, proving the existence of ion confinement in a cusp ECR ion source. The last run was prematurely stopped but the project restarted in 2018 and new experiments are planned in 2021. A new transport beam line has been designed to improve ion beam transport towards the beam detectors. Short- and long-term research plans are presented, including numerical simulations of the beam transport line and future upgrades of the ion source with the main goal to transform the high current density measured into a real high intensity ion beam.
	Slides TUZZO04 [5.933 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO04
About •	Received ※ 28 September 2020 — Revised ※ 15 January 2021 — Accepted ※ 14 February 2021 — Issue date ※ 14 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUZZO05	Multi-Species Child-Langmuir Law with Application to ECR Ion Sources	106
	C.Y. Wong ORNL, Oak Ridge, Tennessee, USA S.M. Lund FRIB, East Lansing, Michigan, USA
	We generalize the classical single-species Child-Langmuir Law to analyze multi-species beams from ECR ion sources. The formulation assumes the relative weight of each species in the extracted beam is known. We apply the results to charge state distribution data from Artemis- and Venus-type sources at the NSCL and LBNL respectively. The total measured beam current is close to the maximum current predicted by the multi-species Child Langmuir law in each case, which indicates that beam extraction occurs close to space-charge-limited flow conditions. Prospects for application of the results and further studies on the topic are outlined.
	Slides TUZZO05 [0.508 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO05
About •	Received ※ 28 September 2020 — Revised ※ 28 December 2020 — Accepted ※ 16 January 2021 — Issue date ※ 18 May 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUZZO06	Beams with Three-Fold Rotational Symmetry: A Theoretical Study	110
	C.Y. Wong ORNL, Oak Ridge, Tennessee, USA S.M. Lund FRIB, East Lansing, Michigan, USA
	Beams from ECR ion sources have 3-fold transverse rotational symmetry induced by the ECR sextupole. The symmetry imposes equality constraints among transverse beam moments, which can be derived using a theoretical framework we developed. Since the constraints are solely a consequence of the rotational symmetry of external fields, they hold for a multi-species beam with arbitrary composition and space charge intensity. These constraints provide a new tool to analyze phase space properties of ECR beams and their impact on low-energy transport. We prove that, regardless of their triangulated spatial density profile, beams with 3-fold rotational symmetry have the same RMS emittance and Twiss parameters along any transverse direction. These counter-intuitive results are applied to the FRIB Front End to show how symmetry arguments challenge long-standing assumptions and bring clarity to the beam dynamics.
	Slides TUZZO06 [0.846 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO06
About •	Received ※ 28 September 2020 — Revised ※ 14 May 2021 — Accepted ※ 18 May 2021 — Issue date ※ 03 November 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Characterization of 2.45 GHz ECR Ion Source Bench for Accelerator-Based 14-MeV Neutron Generator

95

S.J. Vala, M. Abhangi, M. Bandyopadhyay, R. Kumar, R. Kumar
Institute for Plasma Research, Bhat, Gandhinagar, India

The 2.45 GHz Electron Cyclotron Resonance Ion Source (ECRIS) has been indigenously developed. This development of ECRIS aims to provide high brightness, stable, and reliable D⁺ ion beam of 20 mA beam current in a continuous (CW) mode operation for an accelerator-based D-T neutron generator. The ECR ion source setup consists of a microwave system, a magnet system, a double wall water-cooled plasma chamber, a high voltage platform, a three-electrode ion extraction system, and a vacuum system. The ECR ion source test setup is installed, and the deuterium plasma is generated. A three-electrode extraction system is designed and fabricated for the ion beam extraction. A ~10 mA deuterium ion beam is extracted from the ECR ion source. The paper covers the detailed experimental setup of ion beam characterization and diagnostics used for measurement of beam profile, beam current, and beam emittance measurements. It also covers the latest results of beam emittance measurements.

Slides TUZZO01 [0.727 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO01

About •

Received ※ 29 September 2020 — Revised ※ 23 December 2020 — Accepted ※ 19 May 2021 — Issue date ※ 28 June 2022

Cite •

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

TUZZO02

Electron Cyclotron Resonance Ion Source Related Research and Development Work at the Department of Physics, University of Jyväskylä (JYFL)

98

H.A. Koivisto, B.S. Bhaskar, A. Ikonen, T. Kalvas, S.T. Kosonen, R.J. Kronholm, M.S.P. Marttinenpresenter, O.P.I. Timonen, V. Toivanen
JYFL, Jyväskylä, Finland
J. Angot, B.S. Bhaskar, T. Thuillier
LPSC, Grenoble Cedex, France
I. Izotov, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia
L. Maunoury
GANIL, Caen, France
O.A. Tarvainen
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project.
Recent research work of the JYFL ion source team covers multi-diagnostic studies of plasma instabilities, high-resolution plasma optical emission spectroscopy, ion current transient measurements to define the total life-time of a particle in the highly charged plasma. The JYFL team also elaborates the magnetic and technical design of the unconventional ion source named CUBE. The R&D work includes, in addition, the commissioning and operation of the high-performance 18 GHz ECRIS, HIISI. The instability measurements have revealed new information about the parameters affecting the onset of the plasma instabilities and shown that different instability modes exist. The ion-beam transient studies have given information about the cumulative life-time of highly-charged ions convergent with the ion temperatures deduced from the Doppler broadening of emission lines. The CUBE prototype has a minimum-B quadrupole magnetic field topology, similar to ARC-ECRIS, and its all-permanent magnet structure has been optimized for 10 GHz frequency. The CUBE design will be presented along with its commissioning status. The status and operational experience with HIISI will be reported as well.

Slides TUZZO02 [9.553 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO02

About •

Received ※ 28 September 2020 — Revised ※ 09 November 2020 — Accepted ※ 03 December 2020 — Issue date ※ 05 May 2021

Cite •

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

TUZZO03

Study on the Correlation between Energy Distribution of Electrons Lost from the Confinement and Plasma Bremsstrahlung on a min-B ECR Plasmas

B.S. Bhaskar, T. Thuillier
LPSC, Grenoble Cedex, France
B.S. Bhaskar, T. Kalvas, H.A. Koivisto, R.J. Kronholm, M.S.P. Marttinen, O.A. Tarvainen, V. Toivanen
JYFL, Jyväskylä, Finland
I. Izotov, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia
O.A. Tarvainen
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Funding: The work has received funding from the Academy of Finland under the Academy of Finland Project funding (No. 315855) and from University Grenoble Alps under EMERGENCE-project.
The study of plasma bremsstrahlung has been used as a diagnostic tool for understanding the behavior of confined plasma in Electron Cyclotron Resonance Ion Sources (ECRIS). In order to understand the relation connecting the confined plasma and the electrons escaping the confinement, a series of measurements have been made to measure the bremsstrahlung produced in the axial and radial direction along with the Lost Electron Energy Distribution (LEED) axially on JYFL 14 GHz ECR. We present here the effect of various source parameters on the axial and radial bremsstrahlung along with the LEED on a min-B confined ECR plasma. The measured LEED has been found to show a correlation with bremsstrahlung measurement and also have observed as a potential diagnostic method for instability. The explanation for observed LEED and bremsstrahlung trends is provided.

Slides TUZZO03 [1.520 MB]

Cite •

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

TUZZO04

Status of the 60 GHz ECR Ion Source Research

102

T. André, J. Angot, M.A. Baylac, P. Sole, T. Thuillier
LPSC, Grenoble Cedex, France
F. Debray
GHMFL, Grenoble, France
I. Izotov, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia

SEISM is a compact ECR ion source operating at 60 GHz developed up to 2014. The prototype uses a magnetic cusp to confine the plasma. This simple magnetic geometry was chosen to allow the use of polyhelix coils (developed at the LNCMI, Grenoble) to generate a strong magnetic confinement featuring a closed ECR surface at 2.1 T. The plasma is sustained by a 300 kW microwave pulse of 1 ms duration and with a 2 Hz repetition rate. Previous experiments at LNCMI have successfully demonstrated the establishment of the nominal magnetic field and the extraction of ion beams with a current density up to ~ 1A/cm². The presence of "afterglow" peaks was also observed, proving the existence of ion confinement in a cusp ECR ion source. The last run was prematurely stopped but the project restarted in 2018 and new experiments are planned in 2021. A new transport beam line has been designed to improve ion beam transport towards the beam detectors. Short- and long-term research plans are presented, including numerical simulations of the beam transport line and future upgrades of the ion source with the main goal to transform the high current density measured into a real high intensity ion beam.

Slides TUZZO04 [5.933 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO04

About •

Received ※ 28 September 2020 — Revised ※ 15 January 2021 — Accepted ※ 14 February 2021 — Issue date ※ 14 July 2022

Cite •

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

TUZZO05

Multi-Species Child-Langmuir Law with Application to ECR Ion Sources

106

C.Y. Wong
ORNL, Oak Ridge, Tennessee, USA
S.M. Lund
FRIB, East Lansing, Michigan, USA

We generalize the classical single-species Child-Langmuir Law to analyze multi-species beams from ECR ion sources. The formulation assumes the relative weight of each species in the extracted beam is known. We apply the results to charge state distribution data from Artemis- and Venus-type sources at the NSCL and LBNL respectively. The total measured beam current is close to the maximum current predicted by the multi-species Child Langmuir law in each case, which indicates that beam extraction occurs close to space-charge-limited flow conditions. Prospects for application of the results and further studies on the topic are outlined.

Slides TUZZO05 [0.508 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO05

About •

Received ※ 28 September 2020 — Revised ※ 28 December 2020 — Accepted ※ 16 January 2021 — Issue date ※ 18 May 2021

Cite •

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

TUZZO06

Beams with Three-Fold Rotational Symmetry: A Theoretical Study

110

C.Y. Wong
ORNL, Oak Ridge, Tennessee, USA
S.M. Lund
FRIB, East Lansing, Michigan, USA

Beams from ECR ion sources have 3-fold transverse rotational symmetry induced by the ECR sextupole. The symmetry imposes equality constraints among transverse beam moments, which can be derived using a theoretical framework we developed. Since the constraints are solely a consequence of the rotational symmetry of external fields, they hold for a multi-species beam with arbitrary composition and space charge intensity. These constraints provide a new tool to analyze phase space properties of ECR beams and their impact on low-energy transport. We prove that, regardless of their triangulated spatial density profile, beams with 3-fold rotational symmetry have the same RMS emittance and Twiss parameters along any transverse direction. These counter-intuitive results are applied to the FRIB Front End to show how symmetry arguments challenge long-standing assumptions and bring clarity to the beam dynamics.

Slides TUZZO06 [0.846 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2020-TUZZO06

About •

Received ※ 28 September 2020 — Revised ※ 14 May 2021 — Accepted ※ 18 May 2021 — Issue date ※ 03 November 2021

Cite •

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