ECRIS-2014 - Classification: Ion beam extraction and optics

Paper

Title

Page

Simulation Of The CERN GTS-LHC ECR Ion Source Extraction System With Lead And Argon Ion Beams

23

V. Toivanen, G. Bellodi, D. Küchler, A.M. Lombardi, R. Scrivens, J.T. Stafford-Haworth
CERN, Geneva, Switzerland

A comprehensive study of beam formation and beam transport has been initiated in order to improve the performance of the CERN heavy ion injector, Linac3. As part of this study, the ion beam extraction system of the CERN GTS-LHC 14.5 GHz Electron Cyclotron Resonance Ion Source (ECRIS) has been modelled with the ion optical code IBSimu. The simulations predict self-consistently the triangular and hollow beam structures which are often observed experimentally with ECRIS ion beams. The model is used to investigate the performance of the current extraction system and provides a basis for possible future improvements. In addition, the extraction simulation provides a more realistic representation of the initial beam properties for the beam transport simulations, which aim to identify the performance bottle necks along the Linac3 low energy beam transport. The results of beam extraction simulations with Pb and Ar ion beams from the GTS-LHC will be presented and compared with experimental observations.

Slides MOOAMH01 [2.525 MB]

MOOAMH02

High Current Proton and Deuteron Beams for Accelerators and Neutron Generators

30

V. Skalyga, S. Golubev, I. Izotov, S. Razin, V. Sidorov
IAP/RAS, Nizhny Novgorod, Russia
T. Kalvas, H. A. Koivisto, O.A. Tarvainen
JYFL, Jyväskylä, Finland
A.V. Maslennikova, A. Volovecky
Nizhny Novgorod State Medical Academy, Nizhny Novgorod, Russia

This paper presents the latest results of high current proton and deuteron beam production at SMIS 37 at the Institute of Applied Physics. In this experimental setup the plasma is created by 37.5 GHz gyrotron radiation with power up to 100 kW in a simple mirror trap. High microwave power and frequency allow sustaining higher density hydrogen plasma in comparison to conventional ECRIS's or microwave sources. The low ion temperature, on the order of a few eV, is beneficial to produce proton beams with low emittance. Latest experiments with hydrogen and deuterium show possibility of beam formation with currents up to 550 mA at high voltages below 45 kV with normalized rms emittance lower than 0.2 pi*mm*mrad. Such beams have a high potential for application in future accelerator research. Also in frames of the present paper it is suggested to use such an ion source in a scheme of D-D neutron generator. Such ion source can produce deuteron ion beams with current density up to 700-800 mA/cm². Generation of the neutron flux with density at the level of 7-8*10¹⁰ s⁻¹cm^-2 could be obtained in case of TiD2 target bombardment with deuteron beam accelerated to 100 keV.

Slides MOOAMH02 [1.961 MB]

MOOAMH03

Optimization Of Low-Energy Beam Transport

33

H.R. Kremers, J.P.M. Beijers, S. Brandenburg
KVI, Groningen, The Netherlands

We have studied the extraction and transport of a low-energy ion beam between an Electron Cyclotron Resonance (ECR) Ion Source and the analyzing magnet. This first part of the transport line is particularly sensitive to emittance blowup caused by ion-optical aberrations and non-paraxiality of the beam. This can be prevented by an appropriate focussing element between ion source and analyzing magnet. We present the results of beam transport simulations for different focussing elements including an einzel lens, solenoid and quadrupole element. These calculations, verified by measurements, lead to a design of an optimal, low-energy beam transport line for ion beams with large beam divergences.

Slides MOOAMH03 [2.910 MB]

MOOAMH05

Combination of Two ECRIS Calculations: Plasma Electrons and Extracted Ions

38

S. Biri, R. Rácz
ATOMKI, Debrecen, Hungary
R. Lang, J. Mäder, F. Maimone, B.R. Schlei, P. Spädtke, K. Tinschert
GSI, Darmstadt, Germany

In strongly magnetized ECRIS plasmas collisions do not influence the path of the charged particle. Electrons and ions can move more freely only along the magnetic field line compared to the transverse direction. Extraction simulation requires that the trajectories of charged particles have to be traced through the plasma chamber. In previous simulations the particle density at the beginning of the trajectory deep inside the plasma has been unknown. Now the full 3D electron tracking within the plasma chamber has been combined with the generation of initial ion starting conditions including particle density for ion tracking. The TrapCAD code has been used to determine the electron spatial distribution in a certain energy window. The idea is that at the places where the electron reaches a specific energy, an ion trajectory can be started. The magnetic field has been modeled with OPERA. The computer code KOBRA3-INP has been used for ray tracing. First results will be discussed and compared with experimental experience. The number of affecting parameters on the operating conditions of the ion source may lead to a multi-dimensional optimization space for simulation.

Slides MOOAMH05 [10.655 MB]

MOPPH006

Direct Injection of Intense Heavy Ion Beams from a High Field ECR Ion Source into an RFQ

52

G.O. Rodrigues, D. Kanjilal
IUAC, New Delhi, India
R. Becker
IAP, Frankfurt am Main, Germany
R.W. Hamm
R&M Technical Enterprises, Pleasanton, California, USA

Beam intensities achievable from high performance ECR sources for highly charged ions are limited by the high space charge. For high performance ECR sources, the stray magnetic field of the source can provide focusing against the space charge blow-up of the beam in addition to the Direct Plasma Injection Scheme (DPIS) adapted from laser ion sources*. A combined extraction/matching system** has been designed for direct injection into a radio frequency quadrupole (RFQ) accelerator, allowing a total beam current of 10 mA for the production of highly charged 238U⁴⁰⁺ (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The RFQ has been designed to suppress neighbouring charge states and to work as a filter for the desired 238U⁴⁰⁺. This reduces the transport problem for the beam line as well as it reduces the emittance for the selected charge state.
* R. Becker et al., PROC. EPAC-2004, TUPLT024
** G.Rodrigues et al., Rev. Sci.Instrum. 85,02A740 (2014)

MOPPH007

Current Developments for Increasing the Beam Intensities of the RIKEN 18-GHz Superconductiong ECR Ion Source

57

T. Nagatomo, V. Tzoganis
RIKEN, Saitama, Japan
O. Kamigaito, M. Kase, Y. Kotaka, T. Nakagawa
RIKEN Nishina Center, Wako, Japan
Y. Kotaka
SHI Accelerator Service Ltd., Tokyo, Japan
Y. Ohshiro
CNS, Saitama, Japan
V. Tzoganis
The University of Liverpool, Liverpool, United Kingdom

Providing intense and highly charged heavy ion beams is one of the most essential and fundamental technologies to explore a trackless frontier so-called “Island of Stability” where relatively stable super heavy elements are considered to exist. Towards this goal, the development of an ion source that can provide a highly charged heavy ion beam with high intensity and low emittance is necessary. In order to provide the desired high intensity ion beam, the beam-radius expansion induced by space charge effects cannot be ignored, and it can cause considerable degradation of the beam emittance. To suppress such effects at the output of an ion source is one of the top priorities in the direction of improving both the quality and intensity of the beam. At first, we plan to examine the space charge effects with a high-intensity beam provided by the 18-GHz Superconducting ECR Ion Source at RIKEN Nishina Center. To measure the degradation of the beam emittance as function of the beam’s intensity, an in-situ emittance monitor system based on the pepperpot technique and applicable to a wide range of beam intensities is being developed. A report on the current status will be presented.

MOPPH009

Status of IMP Permanent Magnet Proton Source for CI-ADS Project

Q. Wu, H.Y. Ma, L.T. Sun, Y. Yang, X.Z. Zhang, Z.M. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

To produce the requested 10 mA proton beam for the China Initiative Accelerator Driven Sub-critical reactor Linac (CI-ADS), electron cyclotron resonance (ECR) ion sources operating at 2.45 GHz have been developed. The CI-ADS proton source developed at IMP can produced stable 35 keV/10 mA continuous wave (cw) beam at the RFQ entrance. The proton beam extracted by a 3-electrode extraction system passes through a low energy beam transport system (LEBT), which is composed of identical solenoids, into the 3.2 MeV radio-frequency quadrupole (RFQ). In order to ensure superconducting cavities commissioning and protection, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the cw beam into a pulsed one. The achieved fall/rise time of the chopper is less than 20 ns. In this paper, the performance of the proton source and the LEBT, such as beam reliability, emittance and beam current tuning will be presented.

Paper	Title	Page
MOOAMH01	Simulation Of The CERN GTS-LHC ECR Ion Source Extraction System With Lead And Argon Ion Beams	23
	V. Toivanen, G. Bellodi, D. Küchler, A.M. Lombardi, R. Scrivens, J.T. Stafford-Haworth CERN, Geneva, Switzerland
	A comprehensive study of beam formation and beam transport has been initiated in order to improve the performance of the CERN heavy ion injector, Linac3. As part of this study, the ion beam extraction system of the CERN GTS-LHC 14.5 GHz Electron Cyclotron Resonance Ion Source (ECRIS) has been modelled with the ion optical code IBSimu. The simulations predict self-consistently the triangular and hollow beam structures which are often observed experimentally with ECRIS ion beams. The model is used to investigate the performance of the current extraction system and provides a basis for possible future improvements. In addition, the extraction simulation provides a more realistic representation of the initial beam properties for the beam transport simulations, which aim to identify the performance bottle necks along the Linac3 low energy beam transport. The results of beam extraction simulations with Pb and Ar ion beams from the GTS-LHC will be presented and compared with experimental observations.
	Slides MOOAMH01 [2.525 MB]

MOOAMH02	High Current Proton and Deuteron Beams for Accelerators and Neutron Generators	30
	V. Skalyga, S. Golubev, I. Izotov, S. Razin, V. Sidorov IAP/RAS, Nizhny Novgorod, Russia T. Kalvas, H. A. Koivisto, O.A. Tarvainen JYFL, Jyväskylä, Finland A.V. Maslennikova, A. Volovecky Nizhny Novgorod State Medical Academy, Nizhny Novgorod, Russia
	This paper presents the latest results of high current proton and deuteron beam production at SMIS 37 at the Institute of Applied Physics. In this experimental setup the plasma is created by 37.5 GHz gyrotron radiation with power up to 100 kW in a simple mirror trap. High microwave power and frequency allow sustaining higher density hydrogen plasma in comparison to conventional ECRIS's or microwave sources. The low ion temperature, on the order of a few eV, is beneficial to produce proton beams with low emittance. Latest experiments with hydrogen and deuterium show possibility of beam formation with currents up to 550 mA at high voltages below 45 kV with normalized rms emittance lower than 0.2 pimmmrad. Such beams have a high potential for application in future accelerator research. Also in frames of the present paper it is suggested to use such an ion source in a scheme of D-D neutron generator. Such ion source can produce deuteron ion beams with current density up to 700-800 mA/cm². Generation of the neutron flux with density at the level of 7-8*10¹⁰ s⁻¹cm^-2 could be obtained in case of TiD2 target bombardment with deuteron beam accelerated to 100 keV.
	Slides MOOAMH02 [1.961 MB]

MOOAMH03	Optimization Of Low-Energy Beam Transport	33
	H.R. Kremers, J.P.M. Beijers, S. Brandenburg KVI, Groningen, The Netherlands
	We have studied the extraction and transport of a low-energy ion beam between an Electron Cyclotron Resonance (ECR) Ion Source and the analyzing magnet. This first part of the transport line is particularly sensitive to emittance blowup caused by ion-optical aberrations and non-paraxiality of the beam. This can be prevented by an appropriate focussing element between ion source and analyzing magnet. We present the results of beam transport simulations for different focussing elements including an einzel lens, solenoid and quadrupole element. These calculations, verified by measurements, lead to a design of an optimal, low-energy beam transport line for ion beams with large beam divergences.
	Slides MOOAMH03 [2.910 MB]

MOOAMH05	Combination of Two ECRIS Calculations: Plasma Electrons and Extracted Ions	38
	S. Biri, R. Rácz ATOMKI, Debrecen, Hungary R. Lang, J. Mäder, F. Maimone, B.R. Schlei, P. Spädtke, K. Tinschert GSI, Darmstadt, Germany
	In strongly magnetized ECRIS plasmas collisions do not influence the path of the charged particle. Electrons and ions can move more freely only along the magnetic field line compared to the transverse direction. Extraction simulation requires that the trajectories of charged particles have to be traced through the plasma chamber. In previous simulations the particle density at the beginning of the trajectory deep inside the plasma has been unknown. Now the full 3D electron tracking within the plasma chamber has been combined with the generation of initial ion starting conditions including particle density for ion tracking. The TrapCAD code has been used to determine the electron spatial distribution in a certain energy window. The idea is that at the places where the electron reaches a specific energy, an ion trajectory can be started. The magnetic field has been modeled with OPERA. The computer code KOBRA3-INP has been used for ray tracing. First results will be discussed and compared with experimental experience. The number of affecting parameters on the operating conditions of the ion source may lead to a multi-dimensional optimization space for simulation.
	Slides MOOAMH05 [10.655 MB]

MOPPH006	Direct Injection of Intense Heavy Ion Beams from a High Field ECR Ion Source into an RFQ	52
	G.O. Rodrigues, D. Kanjilal IUAC, New Delhi, India R. Becker IAP, Frankfurt am Main, Germany R.W. Hamm R&M Technical Enterprises, Pleasanton, California, USA
	Beam intensities achievable from high performance ECR sources for highly charged ions are limited by the high space charge. For high performance ECR sources, the stray magnetic field of the source can provide focusing against the space charge blow-up of the beam in addition to the Direct Plasma Injection Scheme (DPIS) adapted from laser ion sources. A combined extraction/matching system* has been designed for direct injection into a radio frequency quadrupole (RFQ) accelerator, allowing a total beam current of 10 mA for the production of highly charged 238U⁴⁰⁺ (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The RFQ has been designed to suppress neighbouring charge states and to work as a filter for the desired 238U⁴⁰⁺. This reduces the transport problem for the beam line as well as it reduces the emittance for the selected charge state. * R. Becker et al., PROC. EPAC-2004, TUPLT024 ** G.Rodrigues et al., Rev. Sci.Instrum. 85,02A740 (2014)

MOPPH007	Current Developments for Increasing the Beam Intensities of the RIKEN 18-GHz Superconductiong ECR Ion Source	57
	T. Nagatomo, V. Tzoganis RIKEN, Saitama, Japan O. Kamigaito, M. Kase, Y. Kotaka, T. Nakagawa RIKEN Nishina Center, Wako, Japan Y. Kotaka SHI Accelerator Service Ltd., Tokyo, Japan Y. Ohshiro CNS, Saitama, Japan V. Tzoganis The University of Liverpool, Liverpool, United Kingdom
	Providing intense and highly charged heavy ion beams is one of the most essential and fundamental technologies to explore a trackless frontier so-called “Island of Stability” where relatively stable super heavy elements are considered to exist. Towards this goal, the development of an ion source that can provide a highly charged heavy ion beam with high intensity and low emittance is necessary. In order to provide the desired high intensity ion beam, the beam-radius expansion induced by space charge effects cannot be ignored, and it can cause considerable degradation of the beam emittance. To suppress such effects at the output of an ion source is one of the top priorities in the direction of improving both the quality and intensity of the beam. At first, we plan to examine the space charge effects with a high-intensity beam provided by the 18-GHz Superconducting ECR Ion Source at RIKEN Nishina Center. To measure the degradation of the beam emittance as function of the beam’s intensity, an in-situ emittance monitor system based on the pepperpot technique and applicable to a wide range of beam intensities is being developed. A report on the current status will be presented.

MOPPH009	Status of IMP Permanent Magnet Proton Source for CI-ADS Project
	Q. Wu, H.Y. Ma, L.T. Sun, Y. Yang, X.Z. Zhang, Z.M. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	To produce the requested 10 mA proton beam for the China Initiative Accelerator Driven Sub-critical reactor Linac (CI-ADS), electron cyclotron resonance (ECR) ion sources operating at 2.45 GHz have been developed. The CI-ADS proton source developed at IMP can produced stable 35 keV/10 mA continuous wave (cw) beam at the RFQ entrance. The proton beam extracted by a 3-electrode extraction system passes through a low energy beam transport system (LEBT), which is composed of identical solenoids, into the 3.2 MeV radio-frequency quadrupole (RFQ). In order to ensure superconducting cavities commissioning and protection, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the cw beam into a pulsed one. The achieved fall/rise time of the chopper is less than 20 ns. In this paper, the performance of the proton source and the LEBT, such as beam reliability, emittance and beam current tuning will be presented.