Electron beam irradiation and its...

Electron beam irradiation and its applications

Siriwan Krainara

Beam dynamics group

Accelerator Technology Division

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EB irradiation Tasks

Motivation

Introduction

Electron beam source

Electron beam irradiation

Irradiation applications

Summary

Motivation

A filling time of the storage is approximately 1 hour and 2 times per day

The booster is available about 22 hours daily.

Beam Test Facility (BTF) at Booster Synchrotron

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Introduction: History of irradiation

1930: Electron beam source (DC high voltage generator, Van der Graaff)

1950: E-beam irradiation was developed for Nuclear irradiation A commercial use for nuclear power plants (cobalt-60 has to be manufactured in a

nuclear reactor)

1950: First commercialized e-beam sterilization by Ethicon, a division ofJohnson & Johnson

1952: Dr. Arthur Charlesby found the cross-linking of polyethylene

1961: The production of polyethylene wire in Japan.

1970: Industrial radiation processing with electron beams

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Introduction: Irradiation applications

The irradiation of materials with electron beams or X rays Physical properties

Chemical properties

Biological properties

Cover a very wide range of accelerators technology. Curing ink

Coatings

Sterilization of medical products

Disinfection and preservation of food

The emerging applications include treatment of waste waters andflue gases

IAEA, 2011

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Introduction: Energy range for application

IAEA, 2013

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Introduction: Around the World

EB Facilities South America

Brazil USA China Japan World

(200 keV – 10 MeV) 20 18 >500 >140 >300 >1800

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Introduction: In Thailand

Energy range: 20 MeVMaximum beam power: 10 kWDose rate: 25 kGyPrice: 270 million baht from Mevex Corporation Ltd. company Food Gemstone

Profit/year: 120 million baht/year

http://www.tint.or.th/

Current particle accelerators used in Thailand about 30machines with the beam energy more than 6MeV (http://www.ams.cmu.ac.th)

Electron beam therapy (EBT)

Electron: Internal mammary, Breast cancer, Skin cancer

X-ray: Brain tumor, Head and neck cancer, Cervical cancer,Ovarain cancer, Spinal metastasis, Prostate cancer, Lungcancer

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Name of organizations Accelerator

energy

Beam

power

Purpose

TINT 20 MeV 10 kW Coloring of gemstone

Thai Klinipro Co. Ltd. 1.8 - 2.4 MeV 10 kW Sterilization of doctor gown

IBA S&I (Thailand) Ltd. 15 MeV 8.5 kW Upgrading of gemstone

Synergy Health (Thailand) Ltd. 3 - 10 MeV 1 - 50 kW Sterilization of medical devices and

packaging, polymers improvement, and

gemstone coloring

Electron beam sources

http://www.iba-industrial.com/accelerators

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Dynamitron

Van der Graaf

Rhodotron

Linac

High voltage

Electron beam irradiation

Energy = penetration

Up to 10 MeV: No radioactivity induced

Electron beam properties Beam directed toward products

Finite product penetration

Controlled treatment zones

High dose delivery giving short treatment

Wide range of energy and power ratings

Equipment can be switched on and off Power = treatment speed P (kW) = E (MeV) x I (mA)

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X-ray processing

Generated by electrons decelerated in high atomic number material (Tantalum, Gold,…)

Bremsstrahlung (braking or deceleration radiation)

High penetration compared to electrons

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EB or X-rays ? Required penetration?

Depends on product density/thickness to be treated

Required throughput? Depends on power of equipment

Required homogeneity of treatment? X-ray better than electron beam

(especially for high density products)

IBA and IPEN-CNEN/SP

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Units of radiation dose

The absorbed dose (D), is the amount ofenergy absorbed per unit mass of irradiatedmatter at a point in the region of interest.

Dose absorbed by the irradiated materialaccompanied by 1 joule (100 ergs) ofenergy.

Treatment dose = quantity of electrons per surface unit measured in Gray The original unit is the rad [100 erg/g]; it is now being widely replaced by the

SI unit, the gray (Gy) 1 Gray = 1 Joule / kg = 1 W.s / kg = 100 rad Dose = k . beam current / scan . product speed (at given energy)

Applications Dose requirements

Environments uGy

Sterization of food 15-30 kGy

Polymerizing 25-50 kGy

Grafting 25-50 kGy

Crosslinking 50-150 kGy

Degrading 500-1500 kGy

Gemstones >> 1500 kGy

Therapy 1-100 Gray

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Electron beam irradiation processing

Applications

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Electron interaction

Ionization radiation is almost entirely absorbed by theelectronic structure of absorber which increases theenergy level of its orbital electron

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Electron beam irradiation processing

Cross-linking

Curing

Grafting

Degradation

Stephen C. Lapin, 2014

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Electron beam irradiation processing (continue...)

Cross-linking

Curing

Grafting

Chain session or Degrading

Energy: 0.5 - 3 MeVBeam current: 50 - 100 mAMaterial: Polymer ( Polyethylene, EVA or EPDM), rubberApplication: Wire, cable

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Electron beam irradiation processing (continue...)

Cross-linking

Curing

Grafting

Chain session or Degrading

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InksPrintingPackagingCoating on metal, wood, glass.

Low energy

Electron beam irradiation processing (continue...)

Cross-linking

Curing

Grafting

Chain session or Degrading

Grafting

Battery separator membranes Fuel cell membranes Absorbents for metal ions Substrates for cell tissue growth Ion exchange membranes

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Electron beam irradiation processing (continue...)

Cross-linking

Curing

Grafting

Chain session or Degradation

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PTFE (Polytetrafluoroethylene or Teflon)CelluloseWood

M. S. Khan et al., 2008

Improvement of properties

Biological and medical sterilization

Food irradiation

Gemstone coloring

Environment treatment

Others

Applications of Radiation Technology20/33

Polymer modification Common polymers (Polyethylene ….)

Monomer, oligomer

Rubber

Commercial products Wire and cable stand higher temperature

Jacketing for central heating and plumbing

Heat-shrinking products are given a memory

Gaskets, seals & other molded parts

Piping and tubing

Polyethylene foam sheet

Hydrogels

Improvement of properties21/33

Robert, W.H, Maranne, E.H, 2012

Improvement of properties (Continue…)

Vulcanization: Convert natural rubber or related polymers into more

durable materials via the addition of sulfur or otherequivalent curatives or accelerators.

Viscosity, stress, relaxation

Treatment of Tires Reduction in material

Higher production rates

Construction of green tiresChakraborty, S.K., 2010

Heat and pressure

Heat and pressure

EB irradiation

Vulcanized rubber

Rubber compound

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Improvement of properties (Continue…)

Semiconductor (> 100 kGy): The fast recovery diodes, power diodes, bipolarpower transistors, power MOSFETs, power rectifiers, IGBT’s, thyristors, and silicon-controlled rectifiers. Decrease the minority carrier diffusion length

Increase electrical property

Improves switching speed

Battery: Surface grafting of acrylic acid creates films Control the ion flow between the cathode and anode of small lithium

Longer useful life than films

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Biological and medical sterilizations

Formed polymers and composite structures and even ceramics for medical products while not losing flexibility.

The sterilization of packaged devices in packaging operations.

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Syringes Catheters DrainsTubing Culture tubes Drain pouchesBandages Absorbent GlovesSurgical gowns Hand towels Lab ware

Food irradiation1. Radappertization:

Reduce the levels of pathogenic and spoilage microorganisms

2. Radurization: Reduce the need for preservatives and fumigation

treatments,

Extend shelf life

3. Radicidation: Pasteurization

4. Radiation disinfestation: Destroy insects or pests

5. Radiation sprout inhibition: Delay the onset of natural processes such as fruit

ripening and sprouting of bulbs and tubers.

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Food irradiation (Continue…)

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Range Applications

Low

(<1

kGy) Sprout inhibition in bulbs and tubers 0.03-0.15 kGy

Delay in fruit ripening 0.25-0.75 kGyInsect disinfestations 0.07-1.00 kGy

Med

ium

Dos

e(1

-10

kGy)

Reduction of spoilage microbes in meat, poultry and seafood under refrigeration 1.50-3.00 kGyReduction of pathogenic microbes in fresh and frozen meat, poultry and seafood 3.00-7.00 kGyReducing microorganisms in spices 10.00 kGy

Gemstones coloring

Improving the color of glass and gemstones: 50-10000Gy

Topaz Peal Citrine Ametista Diamond Quartz Spodumene (LiAlSi2O6)

Topaz

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Ti, V, Cr, Mn, Fe, Co, Ni, Cu, … Color centers

Environments treatment

IAEA, 2013

Flue Gas Cleaning

Wastewater

Sludge treatment

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Phase Objects Additives ProcessingGas Flue gas Sox, NOx Removal

VOC Organic compounds Degradation removalLiquid Drinking water Chemical pollutants Degradation removal

Wastewater Bacteria, viruses, parasites HygenizationIndustrial waste Organic and nonorganic

compoundsDegradation removal

Solild Sewage sludge Bacteria, viruses, parasites Degradation removalSolid material Architure wastes Transformation

Flue Gas Cleaning

Summary

Applications Energy PowerX-ray sterilization 10 MeV 130 kWSurface sterilization Low energy 1 kWMedical product sterilization, food 2 - 10 MeV 5 - 25 kWPolymer pipes cable 5 MeV 50 kWPolymerization 10 MeV 130 kWDiodes of BHEL power reduce time 2-10 MeV 0.5 kWGemstones 3 - 50 MeV 10 - 500 kWEnvironment 0.5 - 2.5 MeV 100 kW

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SPS electron beam parameters at SLRI

Beam parameters LBT HBT

Energy 40 MeV 1.0 GeV

Beam current 50 mA 15 mA

Pulse width 2 us 8.5 ns

LBT

HBT

(SLRI Tech. 2006)

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Thank You