Use of the focusing multi-slit ion optical system at the diagnostic injector RUDI A.Listopad 1, J.Coenen 2, V.Davydenko 1, A.Ivanov 1, V.Mishagin 1, V.Savkin 1, G.Shulzhenko 1, B.Schweer 2 and R.Uhlemann 2 1 Budker Institute of Nuclear Physics SB RAS, Novosibirsk, RUSSIA 2 Trilateral Euregio Cluster, Institut fuer Energie- und Klimaforschung, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Juelich, Germany 1

Madrid Padova Lausanne Juelich

List of NBI parameters TEXTOR DNBI ALCATOR DNBI TAE HNBIMST HNBI Beam energy, keV Max. extracted current, A Duration, s8210,02 Beam divergence, degrees 0,35 x 0,60,5511,2 Ion species, % (by current) 85/10/590/5/570/10/2080/10/10 Diagnostic served CXRSMSE, 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 driver Emitter 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 current3 A – Beam current in 50keV neutrals1.5 A – Beam pulse duration6-8 sec (modulated) – Focal length4 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 kV U2=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 1 st gap)

Modernized RUDI arc-discharge plasma generator Enhanced 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 (n e (line average)) n*10 13, cm

Shots /115843; Ti measurements (total averaging 5.5 s). Flat top: 0.8 – 6.8 s, RUDI operation s, Analyzed 1.3 – 6.8 s.

Shots /115843; v p measurements (total averaging 5.5 s). Flat top: 0.8 – 6.8 s, RUDI operation s, Analyzed 1.3 – 6.8 s.

Averaging 1 s (115845) vs 5,5 s intervals (115838, ) All the results of T i measurements have very stable repetition (Even with 1 s time averaging)

Shot ; Density Steps s, s, s. n*10 13, cm

 1 s is enough for T i and almost enough for rotation analysis Ion Temperature measurements: Analyzed intervals for s, s, s. Poloidal velocity measurements: 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!