Use of the focusing multi-slit ion optical system at the diagnostic injector RUDI

A.Listopad1, J.Coenen2, V.Davydenko1, A.Ivanov1, V.Mishagin1, V.Savkin1, G.Shulzhenko1, B.Schweer2 and R.Uhlemann2

1Budker Institute of Nuclear Physics SB RAS,630090 Novosibirsk, RUSSIA

2 Trilateral Euregio Cluster, Institut fuer Energie- und Klimaforschung,Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, 52425 Juelich, Germany

1A.A.Listopad@inp.nsk.su

Madrid

Padova Lausanne

Juelich

List of NBI parameters

  TEXTOR DNBI

ALCATORDNBI

TAE HNBI MST HNBI

Beam energy, keV

20-50 20-55 20-40 25

Max. extracted current, A

3 6.5 40 50

Duration, s 8 2 1 0,02

Beam divergence, degrees

0,35 x 0,6 0,55 1 1,2

Ion species, % (by current)

85/10/5 90/5/5 70/10/20 80/10/10

Diagnostic served

CXRS MSE, CXRS

NBI with focused beam (40 kV, 40 A, 1 s, and >10 kW/cm2)

Atomic driver based on arc generator

Lanthanum hexaboribe thermocathode

Arc-discharge channel

Converter

H

Water cooling

0

Multi-head source based on arc generators

Atomic driverEmitter region

Expander

Arc generator as the source of dense particle flux

Arc plasma source

Magnetic coil transporting system

Sample surface

Density of plasma flow at the anode outlet is 10*(14)/cm2. With the magnetic coil system this can be transported and focused with similar density at the sample surface.

B ~ 1 kGs

Outlines

• RUDI modernization overview

– New ion-optical system

– Optical diagnostic setup

– Metal ceramic arc element

• CXRS measurements

• Summary and outlook

Outlines

• RUDI modernization overview

– New ion-optical system

– Optical diagnostic setup

– Metal ceramic arc element

• CXRS measurements

• Summary and outlook

RuDI neutral beam injector

Nominal beam parameters:– Energy of particles (Hydrogen) 50 keV– Ion current 3 A– Beam current in 50keV neutrals 1.5 A– Beam pulse duration 6-8 sec (modulated)– Focal length 4 m– Diameter 1/e (at the focal plane) 50 mm x 80 mm– Angular divergence ±0.35° x ±0.6°

Round and slit RUDI beamlet geometries

BEAM

U1=50 kVU2=43 kV

U3=-500 V

U4=0 V

Slit RUDI grids photos

Beam components scans across the slits at 45 kV

RUDI beam divergence scan at 45 kV (6,6 kV 1st gap)

Modernized RUDI arc-discharge plasma generatorEnhanced anode shape

O-rings sealed arc channel version

CH1: Arc Current (100 A/check)CH2: Arc voltage (20 V/check)

CH1: HV (10 kV/check) CH2: Beam current (1 A/check)

RUDI 8 second shot oscillorgammes

RUDI typical beam species composition

Outlines

• RUDI modernization overview

– New ion-optical system

– Optical diagnostic setup

– Metal ceramic arc element

• CXRS measurements

• Summary and outlook

Charge-eXchange Recombination Spectroscopy

Lower observation system

Upper observation system

H-beam

DED

Toroidal observation

system

TEXTOR plasma density traces (ne (line average))

n*1013, cm-3

4

3

2

1

Shots 115838/115843; Ti measurements (total averaging 5.5 s).

Flat top: 0.8 – 6.8 s, RUDI operation 1.3-7.5 s, Analyzed 1.3 – 6.8 s.

Shots 115838/115843; vp measurements (total averaging 5.5 s).

Flat top: 0.8 – 6.8 s, RUDI operation 1.3-7.5 s, Analyzed 1.3 – 6.8 s.

Averaging 1 s (115845) vs 5,5 s intervals (115838, 115843)

All the results of Ti measurements have very stable repetition

(Even with 1 s time averaging)

Shot 115845; Density Steps 1.2-3.1 s , 3.1-4.1 s , 4.1-5.5 s.

n*1013, cm-3

4

3

2

1

1 s is enough for Ti and almost enough for rotation analysis

Ion Temperature measurements:

Analyzed intervals for 1.3-3.1 s, 3.1-4.1 s, 4.1-5.5 s.

Poloidal velocitymeasurements:

Ti[eV]

R[m]

v[km/s]

R[m]

Summary

• Optical beam diagnostic complex was developed• New slit ion optics is introduced (June 2010)• Beam current achieved 2,8A (at 49 kV, due to HV PS power limit) • Beam diameter at 2m ~3cm along the slits• Beam species composition ~80% protons• More than 100% CXRS signal level rise• New arc-discharge element has provided 6-8 s beam duration

Summary

• Optical beam diagnostic complex was developed• New slit ion optics is introduced (June 2010)• Beam current achieved 2,8A (at 49 kV, due to HV PS power limit) • Beam diameter at 2m ~3cm along the slits• Beam species composition ~80% protons• More than 100% CXRS signal level rise• New arc-discharge element has provided 6-8 s beam duration

Thank you very much!