CABINET X-RAY MACHINE AND SMALL-SCALE IRRADIATION

Peter Follett, Research EntomologistUSDA-ARS

U.S. Pacific Basin Agricultural Research CenterHilo, Hawaii

Overview

• Who wants small scale irradiators?

• In-line cabinet X-ray irradiator

• Radsource’s 4-Pi X-ray tube

• Comet’s X-ray emitter

• Potential for E-beam

Hawaii pride X-ray irradiator

Phytosanitary irradiation What is the feasibility of in-line irradiation?

Airport baggage screening

Cabinet X-ray irradiatorsWhy growers might be interested…

• Costs a fraction of a stand alone facility (<$1 million)

• Treat fruit the same day it’s packed – no transportation

• Moveable - ready-made for domestic quarantines

• Under grower’s control

• Methyl bromide alter.

• Can treat fruit cold

• Simple solution

Potential application:

• Sweet cherries to Australia and Mexico (spotted wing drosophila)

Requirements

• Good penetration

Different box types

• Good dose uniformity ratio

At 400 Gy, <1 kGy maximum

• Sufficient throughput

• Gentle on commodity

• Low cost

• Portable, self-shielded

• Reliable during continuous use

• Two candidates:

X-ray emitter

4-P1 X-ray tube

In-line cabinet X-ray irradiatorXBA-180 X-ray emitter

Concept design: Dominique Cloetta

Comet AG

XBA-180 X-ray emitter

Comparison to conventional X-ray tube

Geometry not optimal

Small angle of radiation

Low dose rate – 1/r2

Large surface emitter

Broad radiation beam

Higher dose rate >1/r

Simulation for papaya boxDr. Dominique Cloetta (Comet)

Gy

m

At 180kV, 4.5kW and 10cm/min conveyor speed:Min. dose: 78Gy, max. dose: 109GyDUR: 1.4 at 5cm/min: Min. dose: 156Gy, max. dose: 218Gy at 1.95cm/min: Min. dose: 400Gy, max. dose: 559Gy at 1.09cm/min: Min. dose: 716Gy, max. dose: 1000Gy

X-ray emitterPapaya test

Comet AG Flamatt, Switzerland

DURFlat = 1.9 Upright = 1.2

X- ray emitter

In-line cabinet x-ray irradiator4-Pi x-ray tube

Concept design: Randy Kirk

Applied Energy Devices

4-pi X-ray tube

12

Transportable Container

Upender

ShippingContainer

PneumaticActuator

PneumaticActuators

Portable X-ray Irradiator

VENT

Lead26”

60”

Power Supplies

ECSCooler Cooler Cooler

7’

= x-ray tube

13’

New x-ray tube design

• Dan Gorzen

• X-ray and Specialty Instruments Inc.

• 160 kV, 20 mA

• 35 cm radiation field

• 10% variation

Cabinet x-ray machineUnder construction

Inside portable container

Self shielded (lead)

Computer interface

Irradiates box from bottom then top

Throughput varies by dose

Potential for electron beam

Ex: Prima Frutta, Linden, CA

• High volume

• 15,000 boxes per day

• 1 box per 4 sec

• Short harvest

• 2 months

• Continuous use

• Treat in cold room

Sweet cherry packing house Single layer of fruit

Potential for E-beam

Ex: Prima Frutta, Linden, CA

• High volume

• 15,000 boxes per day

• 1 box per 4 sec

• Short harvest

• 2 months

• Continuous use

• Treat in cold room

Sweet cherry requirements In-line e-beam

Size versus performance

• Boxes

• DUR

1.5

• Throughput

100s lbs/hr

• Cost

$1 million

• Carrier

• DUR

1.5-2.0

• Throughput

1000s lbs/hr

• Cost

$3-10 million

Small Medium Large

• Pallet

• DUR

2.5- 3.0

• Throughput

10,000s lbs/h

• Cost

$10-30 million