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RADIATING Z-PINCH INVESTIGATION AND RADIATING Z-PINCH INVESTIGATION AND

““BAIKAL” PROJECT FOR ICFBAIKAL” PROJECT FOR ICF

21st IAEA Fusion Energy Conference16 - 21 October 2006

Chengdu, China

Grabovski E., Grabovski E., SRC SRC RF TRINITI RF TRINITI

Presented byPresented byA. KingsepA. Kingsep

Kurchatov InstituteKurchatov Institute

TRINITI

ANGARA-5-1

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Z-pinch used wire arrays is a most Z-pinch used wire arrays is a most energetic source of x-ray radiation. energetic source of x-ray radiation.

In experiments with wire arrays was In experiments with wire arrays was received record energy contribution in received record energy contribution in spherical target spherical target

Electrical Electrical

EfficiencyEfficiency == 14 14%%

EE X-ray X-ray == 1.81.8 MJ MJ

TT X-rayX-ray == 6 6 ns ns

RRinitialinitial/r /r finalfinal = = 1515

N N D-D-DD == 10101313

((«Z», «Z», SandiaSandia, , USA)USA)

MOTIVATIONMOTIVATION

COMPRESSION WIRE ARRAYS COMPRESSION WIRE ARRAYS DIFFERS FROM CLASSICAL DIFFERS FROM CLASSICAL

MODEL OF THE SNOW PLOUGHMODEL OF THE SNOW PLOUGH

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Two ways of investigations:Two ways of investigations:

Physics of wire array implosion for ICF Physics of wire array implosion for ICF

Design of generator “BAIKAL” - power Design of generator “BAIKAL” - power Z-pinch X-ray source for ICF Z-pinch X-ray source for ICF

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SNOW PLOUGH COMPRESSION SNOW PLOUGH COMPRESSION

AND AND PROLONG PLASMA PRODUCTIONPROLONG PLASMA PRODUCTION

Initial Wire Shell Shell FinalInitial Wire Shell Shell Final

stage breakdown formation implosion stagnationstage breakdown formation implosion stagnation

Wire Wire TrailingWire Wire Trailing

core core and lost masscore core and lost mass

expansion disappearance formationexpansion disappearance formation

ANGARAANGARA-5-1 (TRINITI)-5-1 (TRINITI)

MAGPIE (IMPERIAL COLLEGE)MAGPIE (IMPERIAL COLLEGE)

Z (SANDIA)Z (SANDIA)

0 5 30 70 90 100 ns0 5 30 70 90 100 ns

5

NUMBER OF UNITS -8

OUTPUT PULSE

ENERGY 600 KJ

PULSE DURATION 90 НС

PULSE CURRENT 4 МА

LOADS: GAS PUFF, WIRE ARRAY, FOAM

ANGARA-5-1ANGARA-5-1TRINITI

ANGARA-5-1

6

m m

cm

3

SINGLE AND NESTED WIRE ARRAY PARAMETERS TRINITI

ANGARA-5-1

Diameter 1.2-2 cm Number of wires in

array20-120 (600)

Wire diameter 4-10 m Specific mass 100-1300 g/cm Array current 3-4 MA Current per wire 100-200 kA Current rise time 100 ns X-ray power 7 TW Minimal X-ray pulse

duration6 ns

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CURRENT DISTRIBUTIONCURRENT DISTRIBUTION

AT INITIAL AND INTERMEDIATE STAGE AT INITIAL AND INTERMEDIATE STAGE

OF ARRAY IMPLOSIONOF ARRAY IMPLOSION

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2 loops2 loops

BBφφ MAGNETIC PROBES DESIGN MAGNETIC PROBES DESIGN

B-probe

CathodeCathode

ARRAY

Current probeCurrent probe

AnodeAnode

0.3 mm0.3 mm

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MAGNETIC PROBES DESIGN and ARRANGEMENT

TRINITI ANGARA-5-1

70 75 80 85 90 95-6

-4

-2

0

2

4

6

t, ns

1013 (A/s) #3899

dI/dt(CW probe)

dI/dt(CCW probe)

ANODE

2 LOOPS (CLOCKWISE AND

COUNTERCLOCKWISE) SIGNALS

OUTER AND INNER ARRAYOUTER AND INNER ARRAY

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AZIMUTHAL MAGNETIC FIELD DISTRIBUTION IN WIRE ARRAY

TRINITI ANGARA-5-1

0 2 4 6 8 10 12 14 0

2

4

6

8

10

12 wires

B

probes mm

mm

ARRAY: 40 tungsten wires, wire diameter 8 m, Array diameter 20 mm, height=10 mm, linear mass 380 g/cm

7 5 0 8 0 0 8 5 0 9 0 0

0

0 . 5

1

1 . 5

2

2 . 5

3

M A M G s

0

0 . 1 2

0 . 2 4

0 . 3 5

0 . 4 7

0 . 5 9

0 . 7 1

r 8 . 5 m m n e a r w i r e

r 3 0 m m

r 8 . 5 m m b e t w e e n w i r e s

7 5 0 7 6 0 7 7 0 7 8 0 7 9 0 8 0 0

- 5 . 2 5

- 3 . 5

- 1 . 7 5

0

2

4

- 8 . 7 5

- 7

T i m e _ n s

k A

C u r r e n t o f s i n g l e w i r e

T i m e _ n s

DIFFERENCE OF MAGNETIC FIELD MEASURED BETWEEN DIFFERENCE OF MAGNETIC FIELD MEASURED BETWEEN WIRES AND NEAR THE WIRES IS SMALL AFTER 40 NSWIRES AND NEAR THE WIRES IS SMALL AFTER 40 NS

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The sign of BThe sign of Bφφ is changing is changing

in process of plasma jet transfer part of current from in process of plasma jet transfer part of current from wire core to array centerwire core to array center

DIFFERENCE OF BDIFFERENCE OF Bφφ MAGNETIC FIELD MAGNETIC FIELD

DISTRIBUTION FOR DISTRIBUTION FOR 0 ns AND 40 ns0 ns AND 40 ns

0 ns 40 ns0 ns 40 ns

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MASS DISTRIBUTIONMASS DISTRIBUTION

INSIDE ARRAY ININSIDE ARRAY IN

INTERMEDIATE INTERMEDIATE

STAGE OF IMPLOSIONSTAGE OF IMPLOSION

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BACKLIGHTING LAYOUT TRINITI ANGARA-5-1

Top view

Wire array

X-pinch

Test wire

Shielding Film

W filter

Side view

Probing quanta energy region 3-5 keVFrame exposure < 1 nsSpatial resolution on array ~ 4 m

X-pinchWire array

current-return postAnode

shielding

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MASS DISTRIBUTION MEASUREMENT BY X-PINCH RADIOGRAPHY

TRINITI ANGARA-5-1

0X, 600

0

3000 g/cm2

0 80 160

0

ns

J SXR

Х-pinch

0

3 MA

Timing X- X-pinch

and implosion

g/cm20

40

7

7

0X, 6000

Mass density profile g/cm2

Specific mass profile profile g/cm

Radial

Load:380g/cm array 12mm 40 W wire 8 9.5 g/cm/wire

Test Test wirewire

corescores

corescores

0.4 mm0.4 mm

15

20 m20 m

Inner array Inner array wirewire

Outer array wireOuter array wire

Array axisArray axis

IMAGES OF WIREIMAGES OF WIRES S IN NESTED ARRAY IN NESTED ARRAY

W, D=12mm, d=6m60 ns prior to the maximum of the X-ray pulse.Outer wire - 50% of initial mass Inner wire - 80% of initial mass

The substance of outerThe substance of outer wires are more rarefied. The size of outer wires are more rarefied. The size of outer is the sameis the same. . Velocity of cores expansion does not depend on a Velocity of cores expansion does not depend on a

flowing past currentflowing past current

Plot of area density of array, Plot of area density of array, m/cm2

1 mm60 ns prior to X-Ray pulse

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FINAL STAGE OF FINAL STAGE OF IMPLOSIONIMPLOSION

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8 FRAMES X-RAY CAMERA8 FRAMES X-RAY CAMERA

(PICO-CAMERA*, CAEP)(PICO-CAMERA*, CAEP)

FRAME EXPOSUREFRAME EXPOSURE 85 ps 85 ps

FRAME-TO FRAME DELAYFRAME-TO FRAME DELAY ~2 ns~2 ns

RESOLUTION ON OBJECTRESOLUTION ON OBJECT ~300 ~300 mm

SPECTRAL RANGE SPECTRAL RANGE ~0.3-1.5keV~0.3-1.5keV

JOINT EXPERIMENTJOINT EXPERIMENT

TRINITI (Angara-5-1) - CAEP TRINITI (Angara-5-1) - CAEP

0 500 1000 1500 20000

20

40

60

80

100

120

140

160

Cat(300 Å Au) + 1.1 m formvar

Cat(300 Å Au) + 1.1 m formvar

+ 2.2 m lavsan

E[eV]

A/MW

Pico-camera response with and without Pico-camera response with and without

additional 2.2 additional 2.2 m lavsan filterm lavsan filter

PICO-CAMERA WORKS IN A LINEAR MODE

PICO CAMERA ALLOWS TO CARRY OUT DIGITAL PROCESSING OF THE X-RAY IMAGES

**This and next page see:This and next page see: Study of a Fine Spatial-Temporal Structure of X-Ray Emission of Z Pinch at the ”Angara-5-1” Installation, V. V. Aleksandrov, Lee Zhenhong, Peng Xianjue at al. BEAM,s

2004, .

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THE X-RAY IMAGE OF Z -PINCH AT THE MOMENT CLOSE TO A MAXIMUM OF RADIATION

Wire array:D= 12 mmN= 60d= 6 m, WT= -1,5 ns before X-ray maximum

IT IS SEEN THE CENTRAL BRIGHT AREA (D ~ 0,5 MM) AND PERIPHERY AREA (D ~ 3 MM) OF Z-PINCH.

WHAT IS THE REASON OF EMISSION FROM PERIPHERY AREA WHERE DENSITY IS RATHER SMALL?

IS IT NATURAL EMISSION OR RE-EMISSION?

CAEP = TRINITI (Angara-5-1)CAEP = TRINITI (Angara-5-1)

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200 400 600 800 1000 1200 14000

2

4

6

8

10

12

a.u .relation

of spectral

sensitivity

E[eV]

Inside a diameter of 0.5-1 mm more hard

quantum’s than on periphery (h ~ 1.75-2) are

radiated.

On periphery H is constant despite of

decreasing of intensities several times.

PROBABLY PERIPHERY PLASMA RE-EMITS

RADIATION OF THE CENTRAL ZONE.

The ratio h of responses for images with and without

additional filter

ALLOCATION OF «HOT» AND «COLD» ZONES

5 5 // 6 6 pinholepinhole

1.8 2 2.20

0.5

1

1.5

2

2.5

3

3.5

cm

1

2

#3 / #4

HH

II55,,

II66

7 7 // 8 8 pinholepinhole

0.2 0.4 0.6 0.80

0.5

1

1.5

2

2.5

3

3.5

cm

1

2

#7 /#8

HH

II77,,

II88

CAEP -TRINITI (Angara-5-1)CAEP -TRINITI (Angara-5-1)

Z-pinch radiusZ-pinch radius

hh

H=I(r)/IH=I(r)/I+f(r(r))

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FINAL STAGE.FINAL STAGE.

ELECTRICAL ENERGY ELECTRICAL ENERGY DEPOSITED TO ARRAY DEPOSITED TO ARRAY

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U=(LI)’ +RI L(t) = (U()d - RIdt)/ I(t)

SIGNALS:

U(t) - separatrix voltage ~ 100 mm from axis

I(t) - current at ~ 55 mm from axis

L00 is measured at testing procedure

Calculated:

L(t) - inductance between separartrix and r(t)

0

55 JdtUW sepr r(t)=rr(t)=r00exp((Lexp((L00-L(t))/2h)-L(t))/2h)

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ENERGY DEPOSITION AT SINGLE ARRAYW60 М=330 g 6 m 20 mm H=15mm

700 750 800 850 900 950-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Time_ns

dI_dt

L0

Us

1MV

700 750 800 850 900 950-1

0

1MV

U(r0)

Psxr

750 800 850 900

0

20

60

100kJ

TW

2

6

10

6mm

780 800 820 840 860 880 9000

2

4

6

8

10

r(t)Psxr

нс

Separatrix voltage and current derivative

Voltage at r0 and X-ray power Radius R(t)mm calculated from L(t)

Energy calculated from U,I X-ray energy and power

P(TW)P(TW)

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750 800 850 900 950

4

3

2

1

0

2

4

ENERGY DEPOSITION AT SINGLE ARRAYADDITIONAL RESISTANCE PRESENCE

60W, 6 m, M=330 g, 12Deposited energy 85 kJCALCULATED FINAL RADIUS RI=25 M !!!

750 800 850 9000

1

2

3

4

5

6

7

8

Ropt= 1mm

!!! Ropt>> RI

The additional resistance presence!

I

U*I

ТВт

МА

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THE «BAIKAL» PROJECTTHE «BAIKAL» PROJECT

The goal - creation of the power source of X-ray radiation for ICF

The base - three flywheel generators TKD-200 (3 GJ) and an inductive storage TIN-900 (900 MJ) in TRINITI

The generation scheme - a step-by-step compressing of the pulse in several inductive storage

The parameters of the ‘Baikal’ installation

Load current 50MACurrent pulse duration 100300 nsElectric pulse power 5001000TWX-ray radiation energy 1015 MJRadiation pulse duration 10 nsMethod of X-ray generation Implosion of plasma liners

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MAGNETIC AMPLIFIERS

ENGINES TKD-200

MAGNETIC COMPRESSORS

TRANSFORMERS

POS

LINER

TIN-900Еstore = 3 GJ Eout = 30 MJ E = 10-15 MJT = 6 s T = 150 ns T = 10 ns

32*2 MODULES

THE BLOCK-SCHEME OF «BAIKAL» FACILITYTHE BLOCK-SCHEME OF «BAIKAL» FACILITY

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THE «MOL» STANDTHE «MOL» STAND

AA prototype of the future module of the "Baikal" generator

The goal - investigation and optimization of the generation circuit of an electric pulse

The "MOL" stand is created in TRINITI

A key circuit units of the stand is tested at separate installations:POS - in «Kurchatov Institute»

Magnetic compressor - "PUMA" installation in TRINITI

Explosive switches - in D.V. Efremov SRIEA (NIIEFA)

Fuse switches - in RFNC VNIITF

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THE BLOCK-SCHEME OF «MOL» STANDTHE BLOCK-SCHEME OF «MOL» STAND

Engine

InductiveStorage, IN1

Collector of Second

Switching Step

Выход МК Вход ППТ

Magnetic Amplifier

Capacitor Bank, 3 mF

Iout = 1,5MA, Uout = 4,5MV, t = 150 ns

Magnetic Compressor

Transformer

POS

Inductive Load

12MJ, 2s

7MJ, 300s

3,2MJ, 100s

3MJ, 2s

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ARRANGEMENT ARRANGEMENT OF «MOL» STANDOF «MOL» STAND

System Control Panel

Vacuum System

Plasma Opening Switch

Transformer Raising Voltage

Magnetic Compressor

Capacitor BankSecond Switching Step of IN1

Magnetic Amplifier Inductive Storage

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MAGNETIC COMPRESSORMAGNETIC COMPRESSOR

Capacitor bank - 3.2 mF, 35 kVEnergy of battery - 2 MJCurrent - 3,2 MAT1/2 - 100 sVelocity of tape - 1 km/s

Photo of the «PUMA» installation Scheme of Magnetic Compressor

Tape

The reasons of plate geometry choice1. Uniform acceleration of the plates along their length2. High output energy at low energy density in the compressed cavity 3. Low cost of the plates4. The possibility of initial magnetic flux generation without additional source of energy

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SCHEMES OF THE CAPTURE OF THE SCHEMES OF THE CAPTURE OF THE

MAGNETIC FLUX IN MCMAGNETIC FLUX IN MC scheme with closing switch) and a large

load cavity (14 cm2)

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MAGNETIC FLUX CAPTURING AND COMPRESSING

-50

0

50

100

150

200

250

300

0 40 80 120 160 200

ex perimentcalculations

time, mcstime, s

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PLASMA OPENING SWITCHES

TASKS:

Output voltage 3-5 MV

Parallel POS working

Design

33

Input Input energy energy storestore

AnodeAnode

CathodeCathode

To outputTo output

Magnetic coilsMagnetic coils

Plasma gunsPlasma guns

Plasma open switch schemePlasma open switch scheme

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SWITCHING OF TWO PRALLEL POS

TOTAL CURRENT 150 kAOUTPUT PULSE DURATION 100 nsJITTER 40 ns

0 10 20 us

0 2 4 us

100 кА

THE OUTPUT SWITCH BEFORE LOAD PROVIDES FULL SWITCHING THE CURRENT TO THE LOAD

THE OUTPUT SWITCH BEFORE LOAD PROVIDES MUTUAL SYNCHRONIZATION OF TWO POS

I

1

I

2

TO MARX

OUTPUT

SWITCH

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•In TRINITI with cooperation with Kurchatov Institute, Efremov Institute and VNIITF are investigated Z-pinches as source of X-ray emission for ICF. Both physical (Angar-5-1) and technical ( test bed “MOL” for “Baikal” generator) problems are under investigations.

At “Angara-5-1” the difference of wire array implosion from “snow plough ” model is investigated. It was demonstrated:

•Up to 40 ns the current flows in separate channels near wires. There are no continuous current envelope up to this time.

•Dense wire plasma cores exist at initial wire array position more than a half of implosion time. Velocity of wire cores expansion does not depend on a flowing past current.

•There are two emissive zone at the moment of maximum X-ray emission. Probably periphery plasma re-emits radiation of the central zone.

•Comparison between radius from optical or x-ray image allow to detect addition resistance without quantitative x-ray measurement

CONCLUSIONS

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At “MOL” the scheme of pulse generation for generator “BAIKAL” is developed.

The following experimental results were obtained when creating the “MOL

module :

•the first two stages of power amplification are in operation. The 30-fold

multiplied current up to 150 mks at a voltage of over 20 kV was produced;

•acceleration characteristics of the MC plates are well predicted using 2-d

calculation models developed;

•a method of initial magnetic flux generation in the area of liner compression

using “capture “ of a flux part from the accelerating contour and 20-fold magnetic

induction amplification in the area of converging accelerated plates has been

experienced;

•the output switch before load provides full switching the current to the load

•the output switch before load provides mutual synchronization of two POS