First experimental measurements of the plasma potential throughout the presheath and sheath at a boundary in a weakly collisional plasma

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Oksuz L., Hershkowitz N.

PHYSICAL REVIEW LETTERS, cilt.89, sa.14, 2002 (SCI İndekslerine Giren Dergi) identifier identifier identifier


Experimental data obtained with emissive probes and Langmuir probes show that the plasma potential profile in the presheath scales as -ephi/T-e=root(x(0)-x)/lambda, consistent with ion flux conservation, and that the sheath consists of a transition region and an electron-free collisionless sheath with thicknesses scaling as lambda(1/5)lambda(D)(4/5) and lambda(D)(ephi/T-e)(3/4), respectively, where lambda is the ion-neutral collision length. Results support Rieman's presheath and transitional region model [Phys. Plasmas 4, 4158 (1997)]. The potential drop over the presheath and transition sheath region were the order of T-e/e and 2T(e)/3e, respectively, increasing with increasing pressure.