ECRIS2024 - Classification: MC3: Fundamental Process and Plasma Studies

Paper

Title

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TUC1

Status and perspectives of the PANDORA experiment: investigating β-decays in magnetized plasmas

D. Mascali
INFN-LNS, Catania, Italy
D. Santonocito
INFN-LNL, Legnaro (PD), Italy

This contribution deals with the upcoming PANDORA (Plasmas for Astrophysics, Nuclear Decay Observations and Radiation for Archaeometry) facility [1], at INFN-LNS, Catania. PANDORA aims at measuring β-radioactivity rates and chemical element opacity in plasmas produced in an electron cyclotron resonance ion trap (ECRIT). The beta-decay rates are expected to vary of several orders of magnitude in a hot plasma, due to the interplay between the nuclear and atomic processes by the so-called bound-state-beta-decay mechanism (BSBD). Variations of decay rates have huge impact in astrophysical scenarios and cosmic nucleosynthesis processes, impacting on the chemical abundances in the Galaxy and in the early Universe. The PANDORA experimental setup will consist of: 1) a superconducting magnetic trap of 700 mm in length, 280 mm in diameter, operating up to 21 GHz, in triple-frequency heating mode; 2) an array of 14 of high efficiency High Purity Germanium detectors used to measure the gamma-rays emitted as by-products of beta-decays; 3) a unique multi-diagnostics system to characterize the plasma, including mm-wave super-heterodyne interfero-polarimeter, Thomson scattering, two high-resolution optical spectrometers, two CCD pin-hole camera systems for X-ray spectroscopy, imaging and tomography, SDD and Si-pin detectors for volumetric spectroscopy, and a mass-spectrometer. The talk will give an overview about the status of the facility construction.
[1] D. Mascali et al., Universe 8 80, 2022

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TUC2

Simulation of Bremsstrahlung emission in ECRIS and its dependence on the magnetic confinement

A. Cernuschi, T. Thuillier
LPSC, Grenoble Cedex, France

Funding: This work is supported by Agence Nationale de la Recherche with the contract # 21-ESRE-0018 EQUIPEX+ NEWGAIN
A Monte Carlo (MC) code dedicated to the electron dynamics in ECRIS was recently completed with a new functionality, allowing to simulate Bremsstrahlung photon emission from the volume interaction of electrons with charged particles inside the plasma. The simulation qualitatively reproduces the experimental anisotropy of the photon spectral temperature previously reported. The effects of variations in the magnetic field minimum Bmin and in the extraction peak on both the electron energy distribution function and the Bremsstrahlung emission are also investigated and reported. The simulation results confirm that only changes in Bmin influences the hot energy tail of the EEDF [1]. The MC high electron statistics allows studying with unprecedent details the location and mechanism responsible for the hot electrons generation in ECRIS, highlighting the crucial role of Bmin in this process.
[1] J. Benitez, C. Lyneis, L. Phair, D. Todd, and D. Xie, IEEE Transactions on Plasma Science, vol. 45, p. 1746, 2017.

Slides TUC2 [3.849 MB]

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TUC3

Microwave transmission measurements at the VENUS ECR ion source

J.Y. Benitez, D.S. Todd, S. Holter
LBNL, Berkeley, CA, USA

The VENUS electron cyclotron resonance (ECR) ion source uses injected 18 and 28 GHz microwave power to resonantly energize electrons for plasma ionization. Waveguide antennas detecting 18 and 28 GHz microwaves located after the extraction electrode exit aperture of the source are used to measure the transmitted microwave power under different source and plasma conditions. In addition, an antenna is placed in the 28 GHz waveguide to measure 18 GHz microwaves that make it back out, during 18 GHz only operation. The relationship between the transmitted and reflected power is investigated. Measuring the transmitted power can aid in understanding how to efficiently couple the microwaves to the plasma so as to achieve the maximum source output. The transmitted power, which is inversely related to the absorbed power, is dependent on the neutral gas pressure, and the minimum magnetic field B_min. The production of ¹⁶O⁶⁺ is also compared with the transmitted power.

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TUD1

Time-resolved measurement of ion beam energy spread variation due to kinetic plasma instabilities in CW and pulsed operation of an ECRIS

86

V. Toivanen, H.A. Koivisto
University of Jyväskylä, Jyväskylä, Finland
J.O. Huovila
University of Eastern Finland, Joensuu, Finland
O.A. Tarvainen
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The energy spread of ion beams extracted from Electron Cyclotron Resonance (ECR) ion sources is influenced by plasma conditions such as the plasma potential, and effects taking place in the beam formation region. Kinetic plasma instabilities have a significant impact on the plasma properties, and consequently on the ion beam energy spread. We present experimental results of time-resolved energy spread behaviour when kinetic plasma instabilities are present in CW and pulsed operation of the JYFL 14 GHz ECR ion source. It is shown that the instability-induced energy spread variation corresponds to a momentary plasma potential increase up to several kV from the steady-state value of 10–30 V. The method for measuring the time-resolved energy spread variation is presented, and the consequences of the energy spread and the underlying plasma potential variation for ECRIS operation are discussed.

Slides TUD1 [3.281 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUD1

About •

Received ※ 13 September 2024 — Revised ※ 18 September 2024 — Accepted ※ 29 March 2025 — Issued ※ 09 May 2025

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TUD2

A novel test-facility for ECRIS plasma diagnostics: optical spectroscopy, X-ray imaging and spectroscopy, mm-wave polarimetry

E. Naselli, A. Pidatella, B. Mishra, B. Peri, D. Mascali, G. Finocchiaro, G.S. Mauro, G. Torrisi
INFN-LNS, Catania, Italy
R. Rácz, S. Biri
Atomki, Debrecen, Hungary

In the frame of the PANDORA project and the SAMOTHRACE ecosystem (Italian PNRR in the EU Next Gen Program contest), two new plasma diagnostics testbenches – PYN-HO and VESPRI2.0 setups – have been developed at INFN-LNS, with the aim to design and improve detectors and techniques beyond the state of art. The PYN-HO prototype is conceived to operate in four configurations: two of them to enhance high resolution X-ray imaging and space-resolved spectroscopy, also including X-ray tomography using multi pin-hole CCD systems, involving algorithms for Single Photon-Counted and High-Dynamic-Range analysis, with related calibrations via SDD; the other two are dedicated to high energy resolution diffractometric spectroscopic measurement in the X-ray and optical domains, based on micrometric gratings. The VESPRI2.0 mm-wave polarimeter is based on an innovative superheterodyne approach to measure plasma-induced Faraday rotation from Lissajous figure detection and estimate the plasma line-integrated density. Prototypes can be installed in ECRIS for several plasma physics studies [4], such as investigations of plasma structure, confinement dynamics, instabilities and turbulence, in-plasma and plasma vessel elemental composition, local thermodynamic parameters, etc. which are directly related to ion beam performances in ECRIS. The design and features of the prototypes and the first characterizations performed with Ar plasma in the INFN-LNS Flexible Plasma Trap will be presented.
[1] D. Mascali et al., Universe, vol. 8, p. 80, 2022; [2] E. Naselli et al., Condens. Matter, vol. 7, no. 1, p. 5, 2022; [3] G. Torrisi et al., Front. Astron. Space Sci., vol. 9, p. 949920, 2022; [4] E. Naselli, Eur. Phys. J. Plus, vol. 138, p. 599, 2023.

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Paper	Title	Page
TUC1	Status and perspectives of the PANDORA experiment: investigating β-decays in magnetized plasmas
	D. Mascali INFN-LNS, Catania, Italy D. Santonocito INFN-LNL, Legnaro (PD), Italy
	This contribution deals with the upcoming PANDORA (Plasmas for Astrophysics, Nuclear Decay Observations and Radiation for Archaeometry) facility [1], at INFN-LNS, Catania. PANDORA aims at measuring β-radioactivity rates and chemical element opacity in plasmas produced in an electron cyclotron resonance ion trap (ECRIT). The beta-decay rates are expected to vary of several orders of magnitude in a hot plasma, due to the interplay between the nuclear and atomic processes by the so-called bound-state-beta-decay mechanism (BSBD). Variations of decay rates have huge impact in astrophysical scenarios and cosmic nucleosynthesis processes, impacting on the chemical abundances in the Galaxy and in the early Universe. The PANDORA experimental setup will consist of: 1) a superconducting magnetic trap of 700 mm in length, 280 mm in diameter, operating up to 21 GHz, in triple-frequency heating mode; 2) an array of 14 of high efficiency High Purity Germanium detectors used to measure the gamma-rays emitted as by-products of beta-decays; 3) a unique multi-diagnostics system to characterize the plasma, including mm-wave super-heterodyne interfero-polarimeter, Thomson scattering, two high-resolution optical spectrometers, two CCD pin-hole camera systems for X-ray spectroscopy, imaging and tomography, SDD and Si-pin detectors for volumetric spectroscopy, and a mass-spectrometer. The talk will give an overview about the status of the facility construction. [1] D. Mascali et al., Universe 8 80, 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC2	Simulation of Bremsstrahlung emission in ECRIS and its dependence on the magnetic confinement
	A. Cernuschi, T. Thuillier LPSC, Grenoble Cedex, France
	Funding: This work is supported by Agence Nationale de la Recherche with the contract # 21-ESRE-0018 EQUIPEX+ NEWGAIN A Monte Carlo (MC) code dedicated to the electron dynamics in ECRIS was recently completed with a new functionality, allowing to simulate Bremsstrahlung photon emission from the volume interaction of electrons with charged particles inside the plasma. The simulation qualitatively reproduces the experimental anisotropy of the photon spectral temperature previously reported. The effects of variations in the magnetic field minimum Bmin and in the extraction peak on both the electron energy distribution function and the Bremsstrahlung emission are also investigated and reported. The simulation results confirm that only changes in Bmin influences the hot energy tail of the EEDF [1]. The MC high electron statistics allows studying with unprecedent details the location and mechanism responsible for the hot electrons generation in ECRIS, highlighting the crucial role of Bmin in this process. [1] J. Benitez, C. Lyneis, L. Phair, D. Todd, and D. Xie, IEEE Transactions on Plasma Science, vol. 45, p. 1746, 2017.
	Slides TUC2 [3.849 MB]
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC3	Microwave transmission measurements at the VENUS ECR ion source
	J.Y. Benitez, D.S. Todd, S. Holter LBNL, Berkeley, CA, USA
	The VENUS electron cyclotron resonance (ECR) ion source uses injected 18 and 28 GHz microwave power to resonantly energize electrons for plasma ionization. Waveguide antennas detecting 18 and 28 GHz microwaves located after the extraction electrode exit aperture of the source are used to measure the transmitted microwave power under different source and plasma conditions. In addition, an antenna is placed in the 28 GHz waveguide to measure 18 GHz microwaves that make it back out, during 18 GHz only operation. The relationship between the transmitted and reflected power is investigated. Measuring the transmitted power can aid in understanding how to efficiently couple the microwaves to the plasma so as to achieve the maximum source output. The transmitted power, which is inversely related to the absorbed power, is dependent on the neutral gas pressure, and the minimum magnetic field B_min. The production of ¹⁶O⁶⁺ is also compared with the transmitted power.
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUD1	Time-resolved measurement of ion beam energy spread variation due to kinetic plasma instabilities in CW and pulsed operation of an ECRIS	86
	V. Toivanen, H.A. Koivisto University of Jyväskylä, Jyväskylä, Finland J.O. Huovila University of Eastern Finland, Joensuu, Finland O.A. Tarvainen STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The energy spread of ion beams extracted from Electron Cyclotron Resonance (ECR) ion sources is influenced by plasma conditions such as the plasma potential, and effects taking place in the beam formation region. Kinetic plasma instabilities have a significant impact on the plasma properties, and consequently on the ion beam energy spread. We present experimental results of time-resolved energy spread behaviour when kinetic plasma instabilities are present in CW and pulsed operation of the JYFL 14 GHz ECR ion source. It is shown that the instability-induced energy spread variation corresponds to a momentary plasma potential increase up to several kV from the steady-state value of 10–30 V. The method for measuring the time-resolved energy spread variation is presented, and the consequences of the energy spread and the underlying plasma potential variation for ECRIS operation are discussed.
	Slides TUD1 [3.281 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-ECRIS2024-TUD1
About •	Received ※ 13 September 2024 — Revised ※ 18 September 2024 — Accepted ※ 29 March 2025 — Issued ※ 09 May 2025
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUD2	A novel test-facility for ECRIS plasma diagnostics: optical spectroscopy, X-ray imaging and spectroscopy, mm-wave polarimetry
	E. Naselli, A. Pidatella, B. Mishra, B. Peri, D. Mascali, G. Finocchiaro, G.S. Mauro, G. Torrisi INFN-LNS, Catania, Italy R. Rácz, S. Biri Atomki, Debrecen, Hungary
	In the frame of the PANDORA project and the SAMOTHRACE ecosystem (Italian PNRR in the EU Next Gen Program contest), two new plasma diagnostics testbenches – PYN-HO and VESPRI2.0 setups – have been developed at INFN-LNS, with the aim to design and improve detectors and techniques beyond the state of art. The PYN-HO prototype is conceived to operate in four configurations: two of them to enhance high resolution X-ray imaging and space-resolved spectroscopy, also including X-ray tomography using multi pin-hole CCD systems, involving algorithms for Single Photon-Counted and High-Dynamic-Range analysis, with related calibrations via SDD; the other two are dedicated to high energy resolution diffractometric spectroscopic measurement in the X-ray and optical domains, based on micrometric gratings. The VESPRI2.0 mm-wave polarimeter is based on an innovative superheterodyne approach to measure plasma-induced Faraday rotation from Lissajous figure detection and estimate the plasma line-integrated density. Prototypes can be installed in ECRIS for several plasma physics studies [4], such as investigations of plasma structure, confinement dynamics, instabilities and turbulence, in-plasma and plasma vessel elemental composition, local thermodynamic parameters, etc. which are directly related to ion beam performances in ECRIS. The design and features of the prototypes and the first characterizations performed with Ar plasma in the INFN-LNS Flexible Plasma Trap will be presented. [1] D. Mascali et al., Universe, vol. 8, p. 80, 2022; [2] E. Naselli et al., Condens. Matter, vol. 7, no. 1, p. 5, 2022; [3] G. Torrisi et al., Front. Astron. Space Sci., vol. 9, p. 949920, 2022; [4] E. Naselli, Eur. Phys. J. Plus, vol. 138, p. 599, 2023.
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)