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R.S. Sandha – On behalf of RRCAT team

[email protected]

Development of Industrial Linacs and Experimental Dosimetry

at EB Processing Facility, Indore

1. Accelerator & Beam Physics Section – Physics design

2. Accelerator Control Systems Division – Control system development

3. Accelerator Magnet Technology Division – Magnetic elements and collinear load development

4. Beam Diagnostics & Coolant Sys Division – Beam diagnostics and precision cooling system

5. Construction & Services Division – Radiological shielding and infrastructure systems

6. Design & Mfg Technology Division – Vacuum brazing and component manufacturing

7. Indus Operations & Alignment Section – Magnet Fiducialization and alignment

8. Industrial Accelerators Division – Facility design, Accel structure, beam experiments, dosimetry, processing

9. Laser Controls & Instrumentation Division – Search, secure & safety system; process interrupt

10. Power Converters Division – Scanning and magnetic supplies, HV measurements

11. Precision Power Supplies Division – Fire alarm and safety system.

12. Pulsed High Power Microwave Division – Electron gun and microwave system

13. Ultra High Vacuum Technology Section – Vacuum system

14. Health Physics Team – Radiation survey and Radiation Safety Duties.

15. RF Systems Division and Accelerator Physics Section for consultation on several technical matters

16. Indian Industries – for a large number of components for iterative developments

Acknowledgement

1. Objectives

2. Development of industrial linacs

3. Beam, accelerator and process requirements

4. Details of Radiation Processing Facility (ARPF)

5. Dosimetry and EB processing

These points will be presented in this talk.

Outline

Introduction

1. Develop 10 MeV rugged indigenous accelerators for societal application

2. Develop beam delivery systems for various applications

3. Develop associated systems for bulk radiation processing (process interrupt handling, energy filter,…)

4. Demonstrate technical suitability of the indigenous accelerators for various societal applications

5. Demonstrate economic viability of indigenous accelerator technology for Indian societal applications

Objectives

AFAD 2019, IUAC, New Delhi

Development of Industrial Linacs

RRCAT has developed two 10 MeV, 5 kW electron linacs for

electron beam radiation processing. The linacs have been

endurance tested for several hundred hours of operation.


Linac-B1

Linac-B Linac-C

Type, Frequency 2π/3, Traveling Wave, 2856 MHz

Beam energy (max.), MeV 10 and 7.5

Beam Pulse Current, mA 200 350 / 475

Energy spread 10% 7% (for 90% particles)

Beam Pulse Duration, s 10 10

Pulse Repetition Rate, Hz 250 300

Average Beam Power, kW 5 10

Current Status Developed In-process

Electron linac specifications


Electron linac systems


18 cell SUPERFISH

simulation - 5 MeV, 3 kW

9.5 / 7 MeV 10 kW

Cavities -

1 – prebuncher

5 – buncher

45 - regular

2D-Electromagnetic

design of Pre-buncher

cavity

Physics Design: 10 / 7.5 MeV Dual Energy 10 kW Electron Linac


Engineering designs

Conceptual and engineering designs


Tolerance < 10 microns, Roughness < 0.2 µm Ra

RF Coupler machining

Dimensional inspection Surface roughness

RF Coupler components RF Coupler machining

Industrial Linac: Machining and Dimensional QC


Transverse deformation plot

Length (mm)

Te

mp

era

ture

, C

D

efo

rma

tio

n, m

icro

ns

Precision chiller (Capacity: 20 kW,

Temperature ± 0.5 ˚C) Temperature plot

-0.400

-0.300

-0.200

-0.100

0.000

0 10 20 30 40 50

De

lta

f, M

Hz

Cavity number

Frequency detuning of cavities

Industrial Linac: Thermal management


Cavities stack brazing

Cusil, 810 C, 5min

2-stage brazing of RF couplers

I stage- Palcusil, 820 C, 5min

II stage- Cusil, 810 C, 5min

Final brazing

Cusil, 810 C, 5min

1st & 2nd cycle 3rd cycle 4th cycle

Industrial Linac: 10 MeV Structure Fabrication


110

115

120

125

130

135

0 5 10 15 20 25 30 35 40 45 50

Ph

ase

ad

van

ce

Cavity number

Phase advance per cell measured using Bead-Pull method

Bead pull setup

Industrial Linac: RF qualification


Control rack Gun PS Klystron Gun Modulator

Linac-B1 with its subsystems under testing at RRCAT


Operating Parameters

Beam Power : 5 kW

Beam Energy : 9 MeV

Beam current : 270 mA

Pulse Width : 10 µs

Endurance test: 30 – 8 hr shifts

Shifted to ARPF after endurance testing at RRCAT

Linac-B1: 8-hour shift operation test


Linac-B1: Endurance test - 90 Hours non-stop operation


Linac-B2

Linac-B2 under qualification at RRCAT


Electron Gun Solenoids

Beam Monitor Electron window and target

• As per regulations, maximum electron energy < 10 MeV (< 7.5 MeV in x-ray).

BPM

Chromatic

magnet

BPM

PSM

BPM

MESUREMENT SLIT FARADAY

CUP SLIT

CT CT

Beam Diagnostics

Typical result of Beam Profile Measurement


6 kW operation

9 kW operation (Short duration)

Endurance test Linac-B2


Date of operation: 20-21, Dec 2017, Uninterruptedly for 32 Hrs.

10 AM

Dec 20, 2017 6 PM

Dec 20, 2017

2 AM

Dec 21, 2017 10 AM

Dec 21, 2017

6 AM

Dec 20, 2017

Beam ON Time (Hrs.)

Endurance test Linac-B2: Nonstop 32 hrs. operation


Facility

EB Radiation Processing Facility at Indore

RRCAT is developing a Radiation Processing Facility at Indore

Fruits & Vegetable Market using these linacs. Facility has been

commissioned with the first linac. Second linac is planned to be

commissioned this year (2019).

The facility has a product handling system, dosimetry system, and

all the necessary infrastructure for demonstrating radiation

processing using the electron linacs.

Several applications of the electron beam will be demonstrated.

Medical

sterilization

Microbial

hygienation

Phytosanitary

irradiation

Mutation

breeding


Targeted Radiation Processing Applications at the Facility

Radioactive source like Cobalt-60

Electron Accelerator applications

Imaging Radiotherapy Surface processing < 3 MeV Bulk processing 10 MeV

Food cans Medical sterilization Quarantine - Fresh fruit

Insect Disinfestation pulses, dried food

Municipal waste treatment

microbial decontamination Spices, herbs

Delay ripening

EB Radiation Processing Facility at Indore


Facility Layout


Equipment room

Linac-B1 during installation


Linacs-B1 and B2 after installation

Dosimetry and

EB Processing

Product density

(g/cc)

Single side Double side

1 3.5 cm 8 cm

0.5 7 cm 16 cm

0.4 9 cm 20 cm

0.3 12 cm 26 cm

0.2 18 cm 42 cm

0.15 23 cm 55

Single sided

Double sided

Product

box

Product

box

Electron beam

Electron beam Electron beam

Electron Beam Irradiation Schemes


Parameters affecting dose and dose uniformity

1. Beam energy

2. Beam current

3. Beam spot size

4. Pulse repetition rate

5. Pulse width,

6. Scanning frequency,

7. Scanning width

8. Conveyor speed

9. Product distance from

window foil

10. Product density

Electron Beam Irradiation Scenario


Dosimetry System

Alanine EPR Dosimetry

System

Dose Range:

0.05 to 50 kGy

Radiochromic

film dosimetry

systems

GaFchromic films

Dose range: 0.05-1 kGy

B3 films Dose range:

1 - 80 kGy

Alanine EPR dosimetry system Radiochromic film dosimetry system

Dosimetry Laboratory at RRCAT


Energy measurement using RISO Al

wedge as per ASTM 51649

Surface dose uniformity along scan direction

Beam Parameters

Energy 9 MeV

SSD 20 cm

Conveyor

speed

0.5 m/min.

Scanning

parameters

8.0 A @

400msec.

±3% over the full box height = 43 cm

Do

se

Un

ifo

rmity s

trip

Radiation Field Characterization


Quick-fly back Profile 1.Beam current

2.Beam spot size

3.Pulse repetition rate

4.Scanning frequency,

5.Scanning width

6.Conveyor speed

7.Product distance

from window foil

88 pulse/scan

=88 pulse/50 cm

= 0.6 cm centre

shift on foil

=0.9 cm on

product surface

Conv. Movement

1.3 cm shift/scan

Surface Dose Uniformity and Harmonization of Operating Parameters


Experimental radiation processing Petri Dishes using 9 MeV

e-beam

Volumetric DUR 1.36

achieved in sterilization of

petri dishes irradiated with

electron beam

Volumetric Dose Measurement as per AERB/RF-RPF/SG-1


Conclusion

1. 10 MeV industrial linacs developed for medical sterilization and radiation processing of agricultural products.

2. Facility commissioned with Linac-B1.

3. Linac-B2 will be commissioned this year.

4. Approvals of the regulatory bodies and licensing bodies to be obtained for radiation processing.

5. Using add-on components, beam power and beam delivery systems of the two linacs will be improved.


1. The ability to double break DNA strands in living organisms such as cells, bacteria and insects making them sterile. • Radiotherapy for treatment of cancer,

• Disposable medical product sterilisation and antiseptic packaging

• Live insect elimination in food,

• Disinfection of the spices and herbs without fumigation,

• Quarantine for fruit flies /weevil in fruit,

• Fungus treatment in food – Salmonella, Listeria,

• E-coli elimination in foods.

2. Ability to penetrate with precisely determinable scattering • X-ray imaging for NDT, Cargo scanning, Medical imaging

3. Ability to form free radicals and form new bonds • Cross linking of polymers, curing, breakdown cellulose • Waste water treatment and Dye elimination • Flue gas treatment

4. Ability to produce mutation for mutation breeding of crop varieties

Properties of electron beam/x-rays which make them usable

However, an appropriate radiological shielding is required for protection

1. Beam parameters. • Adjustable beam energy 7 MeV / 9.5 MeV

• Low energy spread

• High beam power (viability begins at ~ 50 kW)

2. Linac requirements • High stability, efficiency, reliability, robust

• Energy filter to eliminate particles higher than regulatory limits

• Low O&M costs and quick recovery after maintenance

3. Process requirements • Ability to handle process interrupt without discarding the product,

• Log the process data and store process data for long time.

• Qualification and routine dosimetry,

• Develop process compatible product packaging.

• Incoming and outgoing product testing and certification.

Important requirements for bulk radiation processing

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