Production of ion beams, instrumental achievements and

NUCLEAR PHYSICS INSTITUTETHE CZECH ACADEMY OF SCIENCES

PUBLIC RESEARCH INSTITUTION

Production of ion beams, instrumental achievements and

maintenance of Tandetronaccelerator in NPI CAS

V. Vosecek, A. Mackova

IAEA Training workshop, 22 – 26. November 2021 V. Vosecek et al

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16 years of Tandetron laboratory in NPI Řež

❑ November 2005 commisioning of 3MV Tandetron in medium current versionwith nitrogen strippingThe Sputter source 860 C and the Duplasmatron 358 in Multipurpose Ion Source (MPI) configuration

2012 The second Duoplasmatron 358 designed for protons has been installed

HV column before inserting The Sputter source 860 C and the Duplasmatron 358 The dual source injector


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Switching magnets and Beam lines

❑ 5-port switching magnet (00, +- 100, +-300), ❑ second switching magnet with 70 port installed on the zero line❑ 5 beam lines, 5 vacuum experimental chambers, 2 external

beam facilities

❑ Beam lines control and monitoring

- Manual and using LabView

❑ LabView which is also used to

control the experiments

The 2 MeV proton beam spot 2x2 mm

in PIXE chamber

LabView panel with beam lines state


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Tandetron operation – experience, problems, breakdowns

❑ SF6 - pressure 6 Bar, dew point below -420 C,

The dew point measurement set

❑ DILO SF6 machine permanentlycoupled with the tank – no leaks

❑ First breakdown - burnedRF resonance coil

❑ Second breakdown –shattered stripper gasvalve shaft

❑ Third tank opening–some diodes replacement

The valve shaft coupled with a clutch

The HV column with a couplingpin


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Accelerator performance

Annual use of Tandetron

Energy calibration

❑ - resonances in p-gamma reactions 27Al(p,𝛾)28Si at 991.90±0.04 keV

13C(p,𝛾)14N at 1747.6±0.9 keV

❑ - neutron threshold reactions 7Li(p,n)7Be at 1880.60±0.0713C(p,n)13N at 3235.7±0.7

y = 1.0054x - 9.1914

0

500

1000

1500

2000

2500

3000

3500

0 1000 2000 3000

2018

2014

2021

Eres (keV)

En (keV)

Energy calibration (years 2014, 2018, 2021)

❑ Operation hours for experiments - around 2000 hours per year❑ Maintanance, conditioning, repairs and tests - around 400 hours per year


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Alpha particles production in Duoplasmatron and Li charge exchange channel

❑ Duplasmatron 358 – a general deterioration❑ Usual setting

- Filament current 17-18 A- Anode current 0.3 – 0.5 A- Magnet current 1000 mA

❑ Charge exchange Lithium channel

❑ Usuall temperature 560 – 5800C

Pt-filament with a fresh coating the demaged coating

Anode surface after 15 years of use

Lithium deposits on the ring between Lithium channel and Einzellens

Anode aperture 0.12”clogged with a drop of melted Fe-Mo-W

Workflows on video:o Duoplasmatron filament preparingo Filament coatingo Lithium charge exchange channel

loading

Demadged Cu-heat shield in front of the Li channel


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The 860 Sputter source and heavy ions production

❑ The 860 Sputter source - principles for long lifetime- the lowest cesium temperature- high ionization current 23-24 A- limit the target current – exceptionally above 0.5 mA

❑ The most common ions for modification - gold, carbon, oxygen, copper and silver

❑ Tested ions

ion target uA7Li- LiN3 -1

12C- graphite -12

14CN- BN+graphite -4

19F- LiF -6

16O- Al2O3+Ag -30

27AlO- Al2O3+Ag -1.6

28Si- Si powder -10

48Ti- Metal -0.25

35Cl- AgCl -10

59Co- Co(AlO2)2+Ag -1

58Ni- metal -1

63Cu- metal -3

107Ag- Co(AlO2)2+Ag -5

127I- AgI -20

184WC- W+graphite -3.4

197Au- metal -20 0

1

10

100

1000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

ions1e10s-1

MeV

1+

2+

4+

5+

C ions vs. Energy normalized to -1uA of C-

3+

❑ Example – accelerated carbon ions in 100 beam line

Video :o Cesium reservoir loading

Cesium ampules


PIXEPIGEPESARBS

m-PIXE, m-RBS, m-PIGE, STIM, External beam station, 3D lithography, 3D elemental mapping

Implantation chamber

RBS, He-ERDARBS-C, PIXE-C

He-ERDA, RBS, RBS-C, ERDA-TOF

RBS and PIXE channelling, ERDA

Research with ion beams – instrumentations

TANDETRON 4130 MC:Source of accelerated ions ( typically from H to Au) with energies from 0.4-25 MeV and intensities up to tens of μA serves for ion beam analysis and new material deposition.

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Nuclear analytical methods:RBS, RBS-Channelling, ERDA, TOF-ERDA, PIXE, PIGE, PESA

Microbeam – lithography and elemental analysis

PIXE-PIGE-PESA-RBS New implantation end-station with diagnostics, cooling and annealing stage

RBS and PIXE channelling, ERDA RBS channelling, ERDA, TOF-ERDA spectrometer


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Ion microprobe and External microbeam

External ion beam set-up Dosimetry studies and detector testing

for space technology


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Openedmicrobeamchamber

The microbeam images, microdevices etc. are realized using our own softwarewritten in LabView enabling to realize microbeam machining and lithography ofany kind of images. software (Scan5.vi ) written in LabView code andimplemented in our laboratory allowed patterning control of complex structures,calculation of dose, configuration of pattern and scan parameters during ionlithography processing.


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PIXE-PIGE-PESA-RBS chamber

New external beam analytical setup for e.g. cultural heritage studies


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New implantation end-station with diagnostics, cooling and annealing stage

Implantation chamber – new version with diagnosticsand heating stage. Heating stage with boroelectric deskuses alternative rare part of the chamber.1 – charge state and energy2 - 3 – parameters for the electrostatic deflectors forhomogeneous steering of the beam4 – on-line control of the implanted fluence andremaining time5- continuous ratemeter and current measurement ionimplantation current being kept in some range6 – Faraday cups – centering of the beam.

Diagnostic part with fluorescence screen, RBS detectorand additional Faraday cup and IR camera fortemperature measurement

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Production of ion beams, instrumental achievements and