Radiation temperature of nonequilibrium plasmas

Arunasalam, V.

doi:10.1063/1.860073

Physics of Fluids B: Plasma Physics

1992

DOI: 10.1063/1.860073

|View full text |Cite

Radiation temperature of nonequilibrium plasmas

V. Arunasalam

Abstract: In fusion devices measurements of the radiation temperature TpCoj.k) near the electron cyclotron frequency to c and the second harmonic 2w c in directions nearly perpendicular to the confining magnetic field B (i.e., k ~ kj_) serve to map out the electron temperature profiles T e (r,t).

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

1994

2023

Publication Types

Select...

Article3

Relationship

Self Cite0

Independent3

Authors

Journals

Cited by 3 publications

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Electron-cyclotron absorption and emission: ‘‘Vexatae quaestiones’’

Bornatici

Engelmann

1994

Physics of Plasmas

View full text Add to dashboard Cite

The salient features of the theory of electron-cyclotron absorption and emission for the parameter range for which the radiation spectrum has a line structure are reviewed and contrasted with erroneous results of a recent paper by Arunasalam [Phys. Fluids B 4, 1643 (1992)]. In particular, (i) the relativistic and nonrelativistic forms of the dielectric tensor relevant to describing the electron-cyclotron absorption are considered, their range of validity is displayed, and on this basis an incorrect suggestion in the above paper on how to obtain the relativistic dielectric tensor from the nonrelativistic one is refuted; (ii) the crucial role of the thermal effects on the mode polarization, which in turn affects the absorption profile around the fundamental frequency, is emphasized, showing that using a ‘‘Trubnikov O-mode factor’’ as advocated in the above paper is not correct; (iii) the profile of the absorption around the fundamental frequency results to be single humped in all cases, in contrast to the assertion in the above paper that the absorption profile of the first harmonic O mode is double humped; (iv) the radiation from a nonuniformly magnetized plasma is evaluated for a bi-Maxwellian electron distribution showing, in particular, that the nonrelativistic treatment used in the above paper is incorrect for perpendicular propagation; (v) an expression for the local radiation temperature obtained in the above paper and upon which the analysis of the emission spectra of supershot plasmas in the Tokamak Fusion Test Reactor (TFTR) has been based by Taylor et al. [Proceedings of the Eighth Workshop on Electron Cyclotron Emission and Heating, Gut Ising, Germany, 1992, (Max-Planck Institut für Plasmaphysik, Garching, 1993), IPP III/186, Vol. 1, p. 277] is shown not to be valid.

show abstract

Electron-cyclotron absorption and emission: ‘‘Vexatae quaestiones’’

Bornatici

Engelmann

1994

Physics of Plasmas

View full text Add to dashboard Cite

show abstract

Sensitivity of synchrotron radiation to the superthermal electron population in mildly relativistic plasma

et al. 2023

View full text Add to dashboard Cite

Synchrotron radiation has markedly different behavior in [Formula: see text] and in [Formula: see text] plasma. We show that high-energy electrons that occupy the tail of velocity distribution function have disproportionate impact on power loss of [Formula: see text] plasma. If electrons with energy more than cutoff energy are redistributed while keeping the Maxwellian distribution function below cutoff energy intact, both emission and absorption of synchrotron radiation act to decrease the lost power. These novel radiation transport effects in non-equilibrium plasma suggest large utility in the deconfinement of high-energy electrons to reduce synchrotron radiation in applications where the radiation is deleterious.

show abstract

Ion cyclotron and spin-flip emissions from fusion products in tokamaks

1994

View full text Add to dashboard Cite

Powerem/ssion byfos_ protium(i.e.,pmu_ sad/oralpha pmictes)_ tokamak plums in their ion cyclotron range of frequencies (ICRP)and attheir spin-flip resonaece fi_quency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma ofsaydeu_=ium (D)is assumed tobein equilierinm (ornonequilibrium) with a Maxwellian distribution both for the e_ and ions (with a possible tempemn_ anisow_y and drift velocity for the D ions). The fusion preduct velocity distributio_ analyzed here are:-(1) A mmoenergetic velocity space ring dis_bufion. (2) A monc_efl_tic _ velocity space spherical shell distribution.(3) An tnisoeropic MaxwelUan dislributkm with Tj. t, Til and with. appreciable drift velocity along the confining magnetic field. Single "dressed" test particle sponmneons emission calculations are presented fn_t and the radiation temperatml for ion cyclomm emission (ICE) is analyzed both for black-body _ and noeequih'brium conditions. Thresholds forinsutbility andovermbifity (i.e.,nel_iverad/atim tempmmm)eruditions arethen and qnm_tln_ar al_ _ theoria of the e_8_etif ion cyclou_ modes are discussed. Dirdn__om betweea "kineticorcausal inmbih" "ues" and"hydrod_ instabilities" are drawn and some numerical esfimaws are presented for typical tokamak parameten. Semiquantitative zemarks are offered on wave _bility, mode conversion, and parametric decay instabilities u possible º,i,m, for spatially localized ICE Cakulafions are carried out bothfork, =0 forI_,, 0. Theera:ts of thetemp=ammanisotropy (i.e..Tj.,, Tl0andlarge eh-ifr velocitiesin thepa-alkldingo, arealto examined.Fually.protmspin-flipresonance emissionand sheer'pCm calculations areaimlm=eared both for_ eqeitibrium conditions andfor an"inverted" pol_dafio, ofrates. Themedmd ofanalysis is thefamiliar _ eqeatim • approach" of nonequilibrium quantum statisd_l mechanic_, based on the Einstein A and B ¢ceffi_enls and the principle of detailed l_ce. Reasonably good _t is obtained between. ._eory and ex_n_ llml_lll,,_I I II

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Radiation temperature of nonequilibrium plasmas

Abstract: In fusion devices measurements of the radiation temperature TpCoj.k) near the electron cyclotron frequency to c and the second harmonic 2w c in directions nearly perpendicular to the confining magnetic field B (i.e., k ~ kj_) serve to map out the electron temperature profiles T e (r,t).

Cited by 3 publications

References 73 publications

Electron-cyclotron absorption and emission: ‘‘Vexatae quaestiones’’

Electron-cyclotron absorption and emission: ‘‘Vexatae quaestiones’’

Sensitivity of synchrotron radiation to the superthermal electron population in mildly relativistic plasma

Ion cyclotron and spin-flip emissions from fusion products in tokamaks

Contact Info

Product

Resources

About