High Power Pulsed Electron

Accelerators

Development for Industrial

Applications

Dr. Archana Sharma

Email : arsharma@apsara.barc.ernet.in

Government of India

BHABHA ATOMIC RESEARCH CENTRE

Beam Technology Development Group

Accelerator & Pulse Power Division

Mumbai-400085- INDIA

Expertise of BARC in Pulsed Accelerators

PRESENT STATUS OF KALI-5000 SYSTEM(0.8-1 MV, 80 kA, 60 ns)

1.5 MV, 25kJ MARX GENERATOR 1MV, 5kJ, 100ns CASTOR OIL BLUMLEIN 1 MV SF6 SPARKGAP SWITCH

GENERATION OF INTENSE RELATIVISTICELECTRON BEAMS (REB)

UTILIZATION OF REB for Flash X-Rays, HPM & Neutrons.

Topics Covered

BARC’s EXPERTISE

Since 1970s,Pulse Power Systems have beenIndigenously Developed by APPD, BARC

*KALI-75, 375kV, 2kA, 180ns;*KALI-85, 780kV, 4kA, 60ns; *KALI-200, 300kV, 15kA, 60ns; *KALI-1000, 300kV, 20kA, 100ns, *KALI-5000, tested up to 600kV, 40 GW, 100ns,

LIA-200, 200kV, 5kA, 100ns, 10-100Hz under commissioning

To make the system compact and repetitive, Consistent efforts are being made.

1

10

100

1000

10000

1970- 1980- 1990- 2000-

KALI-75

KALI-200

KALI-1k

KALI-5k

* KALI: Kilo- Ampere Linear Injector

Schematic of KALI-5000

Pulsed Accelerator

1MeV electron beam pulse

Photograph of the

KALI-5000 PULSED Accelerator

(0.8-1MV, 80kA, 100ns, 5kJ)

KALI-5000 SYSTEM (0.8-1MV, 40kA, 100ns, 40GW)

MARX

GENERATOR

Vacuum

System

Diode end

Blumlein

HVDC

Supply

SF6gas

Roots

Pump

Principle of Marx Generator

R

(b ) EQ U IVA LEN T C IR C U IT

NC o

LR

CH

AR

GIN

G

PO

WE

R

SU

PP

LY

L S

S

TR IG

B

R B 1

1

1SC 1

C

(c) O U TPU T PU LSE SH A PE

t

R L

Vo

B 3

S

B

B 2

2

R

S2

S

C 2

SC

B 3

C

3

3

C S

N

B NR

NSC

SC

RCV R A 1 A 1 A 3A 2 A 2 R A 3 A NR

(a) SC H EM A TIC C IR C U IT O F M A R X G EN ER A TO R

Operation of ± Marx Generator

SSSS

CCC

CCC

RRR

RRR

RRR

S

CC

G

A

G15

B

15

B15

28 30

29

A15

27

G14

MODULE-5

G13

25

A13 A14A

GR

5C

G3

14

26

B14

13

B13

6

B

3

R

4

B3

2

B2

G2

R

R

3C

G1

RA2

R

a

1C

RR

+50kV

HVDC

CHARGING

POWER

SUPPLY

CH+

A) WHILE CHARGING :

2

TRIG.S1

B1R

TRIG.

R-50kV CH-

GND

A3

R

MODULE-1

Operation of ± Marx Generator

S

B) WHILE DISCHARGING :

V-PROBE

10Ω

LR

1 2 S 3

S 4 S 5 S 6

12C11C10C9C8C7C

6C5C4C3C2C1C

S

C 25 C 26 C 27 C 28 C 29 C 30

15S14S13S

FIRST MODULE

SECOND MODULE

FIFTH MODULE

Assembly of Marx Modules

SPARK GAP

PERSPEX SHEET

PLASTIC

CAPACITO RS0.7m F, 50kV

PERSPEX

CLAM P

SUPPO RT TROLLEY

FO R M O DULES

CHARG ING

RESISTORS

M ARX GENERATOR FOR KALI-5000

NYLON RO D

PHOTOGRAPH OF THE FIRST MARX MODULE

(END VIEW)

Photograph of the

Assembled Marx Modules

1.5MV, 25kJ

PULSE FORMING LINE

(PFL)

Inner electrode

cV cR

Outer electrodeZo

LOAD

S

V 1

2o=

Dielectric Medium

Vc

THREE ELECTRODE CO-AXIAL BLUMLEIN

LENGTH-L

23R2

E Z

FAST

SPARKGAP

OUTER

CYLINDER

εrεr

E Z 12

INTERMEDIATE

CYLINDER

INNER

CYLINDER

-1MV

100ns

02312

0L

MATCHED LOAD

Z = 2 ZWHERE Z = Z =Z

CHARGING

INDUCTOR

V

500ns0

-1MV

From High

Voltage Pulse

Generator

R1

DESIGN EQUATIONS OF PFN MODULE

Characteristics Impedance, ZOM = (L /C )1/2

Pulse,TOM = 2n (LC )1/2

Rise Time, tr = 0.3 (LC)1/2

Energy, EM = ½ nC (VC)2

Output Voltage, VOM = ½ VC

2-electrode PFN

End View of The Blumlein

Sparkgap and

Prepulse Inductor

PULSE Generator

(Marx/Tesla Transformer)

Results of KALI-5000

Scale: 20kA/div.,

20ns/division

Scale: 200kV/div,

500ns/division

High VoltagePulse Forming Line

Water/oil filled

H.V.Switch

(spark gaps-

N2/SF6 filled)

REB diode/

e-GUN

Marx Output

Peak Voltage =

600kV.

Charging time =

500ns.

E- Beam current

Imax = 71kA at

600kV.

FWHM = 100ns.

Relativistic Electron Beam

REB Generation

VA CUU M

PULSE

POW ER

SYSTEM

CATHOD ESOLINOID

C OILS

FO IL

AN ODE

INSU LATO R ELECTRO N

BEAM

BEAM TRAN SPORT

R EGIO N

FO

ILA

NO

DE

CA

TH

OD

E

EL

EC

TR

ON

B

EA

M EX

PA

ND

ING

AN

OD

E P

LA

SM

A

DIODE GAP

EX

PA

ND

ING

C

AT

HO

DE

PL

AS

MA

Virtual Cathode Oscillator

(VIRCATOR)

VIRTUAL CATHODE

CATHODE

PULSE

POW ER

SYSTEM

VACUUM

W INDOW

HPM

ANODE

VACUUM

HPM weapons offer military commanders the option of:

(i) Speed-of-light, all-weather attack of enemy electronic systems(ii) Area coverage of multiple targets with minimal prior information

on threat characteristics(iii) Surgical strike (damage, disrupt, degrade) at selected levels of combat(iv) Minimum collateral damage in politically sensitive environments(v) Simplified pointing and tracking(vi) Low operating costs

~ 1GW

Backward Wave Oscillator

BWO-HPM device

V A C U U M

A N O D E

H P M

V A C U U M

W IN D O W

P U LSE P O W ER

S Y STEM

C A T H O D E

M A G N E T IC FIE L D

C O IL S

M A G N E T IC F IE L D

C O IL S

SL O W W A V E ST R U C T U R E

SL O W W A V E ST R U C T U R E

5 MWEfficiency: 20%

TARGET

Beam Plasma Device

For HPM generation

TARGET

ANODE

PLASMACATHODE

PULSE

POWER

SYSTEM

VACUUM

WINDOW

HPM

VACUUM

Wide BW~100GHz, Low Efficiency

Flash X-Rays

For a successful dynamic radiography,

(i) If higher the velocity of the moving object, smaller duration of the X-ray flash will be needed.

(ii) Blurr produced on the stop motion radiography = VxTfor an object moving with velocity ‘V’ & X-ray pulse duration ‘T’

8R/pulse

FLASH X-Ray Generation

INSULATOR BODY

CATHODEVACUUM

ANODE

X-RAY FLASH PROFILE

PULSE

POWER

SYSTEM

INSULATOR BODY

INPUT PULSECATHODE

X

Y

SECTION AT X -Y

ANODE

APPLICATIONs of FXR:(i) Radiography of radioactive sources:

8Ci Ir-192 source radiographed (KALI-200)(ii) Imaging the impact of projectile in or on a target,(iii) Imaging an explosively driven object during acceleration(iv) Observing the mechanics of detonation

Flash X-Ray Generation

Flash X-ray from KALI-75 Normal X- ray Photograph of water drops

VACUUM

ANODE

PULSE

POWER

SYSTEM

CATHODE

VIRTUAL

CATHODE

IONS

e_

IONS

CROSS MAGNETIC

FIELDION SOURSE

Collective Ion Collective Ion AcceleraionAcceleraion

CONCLUSIONSCONCLUSIONS

AN ELECTRON BEAM OF 600kV, 70kA, 100ns has been produced.

HPM ~1GW POWER, for shielding applications.

FLASH X-RAYs for deeper & faster radiographyION IMPLANTATION

for various Industrial Applications

THANKTHANK YOUYOU