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PL ASMA ACCELERATORS: THE WAY TO NEW TECHNOLOGIES

Yuliia Volkova1, I.E. Garkusha1,2, V.O. Makhlai1, S.S. Herashchenko1,

D.G. Solyakov1, T.M. Merenkova1, M.S. Ladygina1,

V.V. Staltsov1, V.V. Chebotarev1,

A.K. Marchenko1, Yu.V. Petrov1, D.V. Yeliseyev1

1Institute of Plasma Physics of the NSC KIPT, Kharkiv, Ukraine

2V.N. Karazin Kharkiv National University, Kharkiv, Ukraine

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Plasma accelerators

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Quasistationary Plasma accelerators in Kharkiv:

QSPA Kh-50 QSPA-M, MPC

Quasistationary – discharge lifetime >> particle

time of flight in the channel

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Motivation

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High-power plasma streams are a unique tool for surface treatment in technological applications.

A broad combination of physical mechanisms: ion bombardment, heat load (melting,

thermal quenching), shock waves, material alloying with plasma species, mixing in

molten stage, fast resolidification (quasi-amorphous transformations), phase changes

  • turbines
  • space apparatus
  • nuclear

engineering

  • fusion

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QSPA Kh–50

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Energy density ρw = (0.5…30) MJ/m2 Plasma pulse duration τ ≈ 0.25 ms Plasma speed above 107 cm/s

Pmax = (3-18) bar

n = (0.2-5) 1016 cm-3

B0 =0.54 T (β ≈ 0.3…0.4)

Diameter of plasma stream = 15 cm

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QSPA–M

Target with calorimeter

Argon injection

Plasma stream

Plasma accelerator

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Parameters

​

Plasma stream energy density [MJ/m2]

0.3 - 1

Load duration [ms]

0.1

Average heat flux [GW/m2]

7.5

Heat flux factor [MWs1/2/m2]

75

Magnetic field, T

1

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Magnetoplasma compressor

Id = 400 kA

T = tens of µs Working gases:

Xe,He, Xe+He, N, Ar

In the compression zone:

N ≈ 1018 cm-3 T ≈ 60-130 eV

Energy density ≈ 0.5 MJ/m2 Plasma flow speed ≈ 107 cm/s

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anode rods

c o m p r e s s i o n z o n e

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Magnetoplasma compressor

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Applications

M P C a s a p o w e r f u l s o u r c e o f p l a s m a

a n d r a d i a t i o n a c r o s s

t h e e l e c t r o m a g n e t i c s p e c t r u m

c o m p r e s s i o n z o n e

He 6−7 µs

Ar 14−15 µs

anode rods

EUV radiation

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Magnetic reconnection as in solar flares?

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Shielding layer formation

This layer decreases surface damage and erosion

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The formation of a dense plasma shield near the exposed surface is a feature of the interaction of powerful QSPA plasma with targets. Such a plasma layer is responsible for decreasing incident plasma energy that is delivered to the surface.

​

The non-uniform shielding layer forms when the plasma interacts with oblique surfaces. The non-homogeneous distribution of the energy density along the exposed surface was observed during the inclined plasma impacts. As a result, the damage of various target parts was significantly different.

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FUSION MATERIALS

Irradiated by a total of 500 QSPA Kh-50 pulses

Unit size of 24×12×5mm3

The width of slits between the elements is

1 mm

The overall target size is 5×5×1 cm3

pronounced

Heat load of 0.9 MJ/m2 melting of exposed surfaces

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FUSION MATERIALS: CPS targets

pronounced

Heat load of 0.9 MJ/m2 melting of exposed surfaces

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Δm~0.05 mg/cm2pulse

texp= 1.2 ms

texp= 1.2 ms

QSPA Kh-50, Q=2.2 MJ/m2

QSPA – M, Q=0.7 MJ/m2

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Construction materials

SEM images at various magnifications of EUROFER sample: in as–received state; exposed to the 10 QSPA plasma pulses of 0.6 MJ/m2

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Hastelloy initial and after pulsed nitrogen plasma treatment of 0.3 MJ/m2