Instability heating of the HDZP

Conference · Fri Jan 01 04:00:00 EST 1993

DOI:https://doi.org/10.1063/1.2949211· OSTI ID:6484584

Lovberg, R H ^[1]; Riley, R A; Shlachter, J S ^[2]

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1. California Univ., San Diego, La Jolla, CA (United States)
2. Los Alamos National Lab., NM (United States)

We present a model of dense Z-Pinch heating. For pinches of sufficiently small diameter and high current, direct ion heating by m=0 instabilities becomes the principal channel for power input. This process is particularly important in the present generation of dense micro-pinches (e.g., HDZP-II) where instability growth times are much smaller than current risetimes, and a typical pinch diameter is several orders smaller than that of the chamber. Under these conditions, m=0 formation is not disruptive: the large E[sub z] field reconnects the instability cusps externally, after which the ingested magnetic flux decays into turbulent kinetic energy of the plasma. The continuous process is analogous to boiling of a heated fluid. A simple analysis shows that an equivalent resistance R[sub t] = [ell]/4[radical]Nm[sub i]([mu][sub 0]/[pi])[sup 3/2]I/r appears in the driving circuit, where I is the pinch current, N is the line density, [ell] is the pinch length, m[sub i] is the ion mass, and r is the pinch radius. A corresponding heating term has been added to the ion energy equation in a 0-D, self-similar simulation, which had been written previously to estimate fusion yields and radial expansion of D[sub 2] fiber pinches. The simulation results agree well with the experimental results from HDZP-II, where the assumption of only joule heating produced gross disagreement. Turbulent ion heating should be the dominant process in any simple pinch carrying meg-ampere current and having submillimeter radius.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6484584
• Report Number(s): LA-UR-93-1318; CONF-9304126--5; ON: DE93012641
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
700350 -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
FLUID FLOW
HEATING
IMPURITIES
INSTABILITY
LINEAR PINCH DEVICES
LINEAR Z PINCH DEVICES
MAGNETIC FLUX
OPEN PLASMA DEVICES
PINCH DEVICES
PLASMA HEATING
PLASMA IMPURITIES
PLASMA INSTABILITY
PLASMA SIMULATION
SIMULATION
THERMONUCLEAR DEVICES
TURBULENT FLOW