C03-1

2006.2.16-2.18,

D. Spong (ORNL)

CHS, LHD JT-60U MHDAEEPMCHS, LHD,JT-60UTEXTOR

(A) AEEPM : LHD, JT-60ULHD : AE ( , NIFS)LHDEPMJT-60U AE(JAEA)

(B) AE: CHS, TEXTOR CHSTAE( JAEATEXTOR DEDAE

(C) AEEPM: CHS, LHD, JT-60U CHS : , EPMs TAEs ( NIFS NIFS) LHDTAE(NIFS) JT-60UAE(JAEA)

(E) : CHSLHDCHS LHD (D. Spong, ORNL, , NIFS)

AEEPM : LHD, JT-60U

Shear Alfvn Spectra(by CAS3D3) - Configuration 1: high magnetic shear (Rax=3.6 m, low ) -We compare these observed frequencies with the global mode analyses by CAS3D3.The n=1, 2 mode are identified with core-localized TAE and global TAE, respectively.The continuum damping due to the high-n modes is quite weak in LHD.Nf=1C-TAEm=2,3G-TAEm=3,4,5Nf=220th IAEA FEC [EX/5-4Rb] presented by S. Yamamoto, S. Yamamoto et al., NF(2005)

Space=20points, Sweep time=0.2sup-stair#57835 Bax=1.0T Rax=3.75m NBI#1(CCW) t>2.3sShear Alfvn SpectraMeasurements of internal structure of AEs by m-wave reflectometern=1n=2T. Tokuzawa et al.9th IAEA TM on EP, 2005

(5-1) Fast Ion Confinement & Energetic Ion Driven AEs/EPMsMagneticProbes

Interfero-metry

No change in energyspectra of chargeexchanged fast neutrals (by P. Gocharov)Observation of multiple higher harmonics in AE/EPM frequency rangeThis may be a new type of AEsBy P. Goncharov)

Excitation of Energetic Particle Modes with Co-NBIApplication of CO-NBI to a plasma with large negative Ip induces enhanced energetic ion loss caused by excited EPMs with m/n=3/1 .FIR data may give information on CO-NBI deposition profile, i.e., off-axis deposition.

JT-60UAEAE

RSAE (Reversed Shear Alfvn Eigenmodes)

Alfven CascadeRSAE

JT-60U

RSRSAERSAETAEqo

TASK/WMITB trigger eventRSAEqmin

AE: CHS, TEXTOR

TEXTOR

AE Spectroscopy System in CHSThis system is composed of two electrodes.Excitation voltage is applied between vacuum vessel and electrodes. Single probe methodExcitation current is induced along a specific magnetic field line.Shear Alfvn waves would be effectively generated.Toroidal Mode Even ModeElectrode9th IAEA Technical Meeting on EPs, 2005, Takayama by G. Matsunaga,G. Matsunaga et al., PRL (2005)

Profiles of Transfer FunctionsTransfer function can be obtained as complex function of frequency and position.The transfer functions clearly show eigenmode at r/a ~ 0.5 and f ~ 100kHz.9th IAEA Technical Meeting on EPs, 2005, Takayama by G. Matsunaga,

Eigen-frequency & Damping rateTo confirm that these modes are related to AEs, plasma parameter were varied.

The observed frequency clearly depends on VA.---AEsDamping rates are about 5 ~ 20%.9th IAEA Technical Meeting on EPs, 2005, Takayama by G. Matsunaga,

Damping rates v.s. Ve/VAElectron pressure converts shear Alfvn wave into kinetic Alfvn wave in the range of Ve >VA.

KAW propagates away from AE gap and is damped by Landau damping. Radiative Damping

It is expected that radiative damping can be effective with increasing Te.

In the range of Ve >VA, the damping rates become larger.Radiative Damping may be a possible candidate of damping mechanisms.

9th IAEA Technical Meeting on EPs, 2005, Takayama by G. Matsunaga,Conditions 0.1

DEDm/n=3/1, 6/212/3q=3Dynamic Ergodic Divertor(DED)1-500kHzAE218T. Shoji et al.9th IAEA TM on EP, 2005, Takayama

LHD, CHS JT-60UEPM

Energy decay time of increased neutral flux was proportional to 1/ne, indicating the increase observed at the lower energy side was due to the classical slowing down process.Energy decay time was examined from the least square fitting of the increased neutral flux peak position to the exponential function .M. Osakabe et al.9th IAEA TM on EP, 2005, TakayamaModulation of Fluxes of Charge Exchanged Fast Particles by Bursting TAEs on LHD

The particles orbit has higher probability of staying around the TAE gap by n=2/m=3~4. M. Osakabe et al. 9th IAEA TM on EP, 2005, TakayamaRelation between TAE gap and Particle Orbit

Creation of a Peak and a Hole with a TAE-burst is simultaniously observed on NPA spectra.The hole starts from 153keV( and can be extrapolated to 180keV at the burst timing) and its typical decay time is 8.3[ms]The peak starts from 153keV and its decay time is 6[ms]M. Osakabe et al. 9th IAEA TM on EP, 2005, TakayamaClump and Hole Formation in NPA Spectra

Lost fast ion probe signals measured at large R side - Bright spot on the scintillator screen due to impact of fast ions -Primary loss spot appears in pitch angle of 130~133 degrees (v///v= -0.64 ~ -0.68).- Measured gyro-radius is consistent with that of ions having Eb.During EPM, scintillation light intensity in more parallel pitch angle significantly increases.shot#122764Rax/Bt=0.974 m/0.92 T5.0Gyroradius centroid (cm) Gyroradius centroid (cm)Pitch angle (degrees)EPM-quiescentphase t=74-75 ms

EPM phaset=85-86 msCo-, parallelFrame rate : 1 kHzPrimaryspotM. Isobe et al. 9th IAEA TM on EP, 2005, Takayama

TAE mode and its effect on beam ionsToroidal Alfvn eigen (TAE) mode is excited by tangentially coinjected NB.- Weak TAE appears between the two pulses.- Significant increase of fast ion loss is not seen when the mode amplitude is small (~1x10-5T )shot#124870 Rax/Bt=96.2cm/0.91TEnlarged pulse t = 87-89 msTAEEPM~M. Isobe et al.9th IAEA TM on EP, 2005, Takayama

TAE mode having higher fluctuation levelFast ion loss due to TAE mode appears when fluctuation level is above 3x10-5 T and rapidly increases as fluctuation level increases.TAE's levelgradually decreasingComparison on beam ion lossesbetween EPM and TAEM. Isobe et al. 9th IAEA TM on EP, 2005, Takayama

M. Ishikawa et al.9th IAEA TM on EP, 2005, Takayama

M. Ishikawa et al.9th IAEA TM on EP, 2005, Takayama

M. Ishikawa et al.9th IAEA TM on EP, 2005, Takayama

M. Ishikawa et al.9th IAEA TM on EP, 2005, Takayama

CHS( D.A. Spong, ORNL)DELTA5D: Orbit equation+Monte Carlo code Modeled magnetic perturbations of which frequency chirping is simulated from experimental data.

Preliminary results of the numerical simulation(1)

Preliminary results of the numerical simulation(2)

Conclusion and Next Steps

18aLFS, HFS), a

JT-60URSAERSAE

: Frequency chirpingEPM, Bursting TAE

A system for AE spectroscopy on LHDVc=150V, I=5A, f< 1MHzTwo exciter coils of 1.2mx0.5m are placed away from 180in the toroidal direction. Then, n=0,1 and 2 are expected.