Cabina de rayos x e irradiación a pequeña escala
-
Upload
procolombia -
Category
Government & Nonprofit
-
view
225 -
download
1
Transcript of Cabina de rayos x e irradiación a pequeña escala
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