Development of a portable OSL reader for spaceflight ......m H. 2. O) (1) OSL from Al. 2. O. 3. shows sensitivity to HCP of LET > 10 keV/µm (up to 290MeV/n Xe; 1047 keV/µm) (2) Sensitivity

Oklahoma State University

Development of a portable OSL Development of a portable OSL reader for spaceflight activitiesreader for spaceflight activities

Eduardo G. Yukiharaand

Stephen. W.S. McKeever

Department of Physics, Oklahoma State University


TL and OSL PrinciplesTL and OSL Principles

Radiation

Radiation sensor(insulating crystal)

EXPOSURETL = thermally stimulated luminescence

OSL = optically stimulated luminescence

Conduction band

Valence band\



STORAGE



Light emission – TL (e.g., blue, UV)

READOUT

Thermal stimulation (heating)



Light stimulation(e.g., green) Light emission

(e.g., blue, UV) - OSL

READOUT



PMTLaser or LEDs(CW or pulsed)

Detection filters

OSL

Dosimeter(OSLD)


The Pulsed OSL (POSL) TechniqueThe Pulsed OSL (POSL) Technique

Pulsed OSL (POSL)Measures OSL emission between stimulation pulses, not during the pulse. Better separation between the signal and the stimulation light.

Stimulate Measure OSL

Akselrod and McKeever, Radiat. Prot. Dosim. 81, 167-176 (1999)


Typical TL and OSL SignalsTypical TL and OSL Signals

100 200 300 4000.0

0.2

0.4

0.6

0.8

1.0

1.2

Al2O3:C chips LiF:Mg,Ti TLD-100

TL (n

orm

aliz

ed)

Temperature (ºC)

TL

0 100 200 300 400 500 6000

100

200

300

400

constant

CW

-OS

L (a

rbitr

atry

uni

ts)

Time (s)

CW-OSL

0.0 0.5 1.0 1.5 2.00.0

0.5

1.0

1.5

2.0

2.5

POSL

pulsed

PO

SL

(arb

itrat

ry u

nits

)Time (s)

POSL


Typical TL and OSL SignalsTypical TL and OSL Signals

100 200 300 4000.0

0.2

0.4

0.6

0.8

1.0

1.2

Al2O3:C chips LiF:Mg,Ti TLD-100

TL (n

orm

aliz

ed)

Temperature (ºC)

TL

0.0 0.5 1.0 1.5 2.00.0

0.5

1.0

1.5

2.0

2.5

POSL

pulsed

PO

SL

(arb

itrat

ry u

nits

)Time (s)

POSL

CW-OSL

0 100 200 300 400 500 6000

100

200

300

400

constant

CW

-OS

L (a

rbitr

atry

units

)

Time (s)


Possibility of RePossibility of Re--estimation of dosesestimation of doses

Can re-read the OSLsignal, if the signal is strong enough. (No need to deplete the signal in order to measure it.)

Akselrod and McKeever, Radiat. Prot. Dosim. 81, 167-176 (1999)


Why develop OSL fro astronaut dosimetry?Why develop OSL fro astronaut dosimetry?

• All-optical method lends itself to multiple configurations and devices

• High sensitivity• Stable signal (no fading)• Re-read of OSL signal (period dose plus total dose)• Re-setting of signal by bleaching• High reproducibility within a batch (e.g. LuxelTM)• Thin dosimeters (e.g. LuxelTM) for ease of use • Fast readout• Low (electrical) power• High reliability of components• Various on-board readout configurations• Can combine with TLD/PNTD badges, and readers


Space & GroundSpace & Ground--Based ExperimentsBased Experiments

Ground-based Experiments

• HIMAC-NIRS• ICCHIBAN 2nd, 4th, 6th

• Peletron-UNAM (low-E p, He, C, O)

• Loma Linda (proton ICCHIBAN)• NSRL-BNL

Space-based Experiments

•STS - several •Soyuz/ISS (MATROSHKA I & II)•Soyuz (MESSAGE; MOBILIZATION)•Soyuz/ISS (BRADOS)•Antarctica Balloon flight (TRACER)

Multiple collaborators


Summary of Major PropertiesSummary of Major Properties

0.1 1 10 1000.0

0.2

0.4

0.6

0.8

1.0

1.2

β

FeS i

C

H e

(a) A l2O 3:C s ing le c rys ta l dos im eters

In tegra ted C W -O S L In itia l C W -O S L in tens ity T L peak he ight

Effic

ienc

y

LET (keV /µm H 2O )

0.1 1 10 1000.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

β

FeS i

C

H e

(b) A l2O 3:C Luxe lTM dos im eters

P O S L In tegra ted C W -O S L In itia l C W -O S L in tens ity

Effic

ienc

y

LET (keV /µm H 2O )

(1) OSL from Al2O3 shows sensitivity to HCP of LET > 10 keV/µm (up to 290MeV/n Xe; 1047 keV/µm)

(2) Sensitivity & precision depend on method of OSL readout

(3) Sensitivity & precision depend on material type (chip, Luxel)



(4) Sensitivity decrease with LET due to loss of sensitivity at high doses

(5) OSL decay rate depends on (a) dose, (b) LET

0 50 100 150 200 250 3000.0

0.2

0.4

0.6

0.8

1.0 β irradiationHe 150MeV/nC 400MeV/nSi 190MeV/nFe 500MeV/n

OSL

(nor

mal

ized

)

Time (s)

0 50 100 150 200 250 3000.0

0.2

0.4

0.6

0.8

1.0

≥ 500 Gy100 Gy

50 Gy

≤ 10 Gy

Al2O3:C LuxelTM dosimeters

CW

-OS

L (n

orm

aliz

ed)

Time (s)

1 10 100

100

101

102

(a) Al2O3:C Chips

BCDLinearityLu

min

esce

nce

Sign

al (n

orm

aliz

ed)

Dose (Gy)



1 10 100

1.0

1.2

1.4

1.6

1.8(a)

Fe

SiC

He

β

Rat

io R

LET (keV/µm in water)

(6) Possibility of LET information from OSL decay curves(a) Ratio of area to initial

intensity(b) Ratio of decay constants

(7) Possibility of LET information from emission spectra

0.1 1 10 100

0.24

0.26

0.28

0.30

0.32

FeSi

C

He

β

(b)

LET (keV/µm in water)

τ 1/ τ 2


OSL from AlOSL from Al22OO33:C: emission bands:C: emission bands

POSL measurements

300 350 400 4500

2

4

6

8Channel B (signal between laser pulses)Channel A (signal during laser pulses)

Wavelength (nm)

OS

L (a

rb. u

nits

)

0

20

40

60

80Transm

ittance (%)


CWCW--OSL from AlOSL from Al22OO33:C: dose dependence:C: dose dependence

1 10 100 1000

103

104

105

(a)

SUVSF-center

Dose (Gy)

OS

L si

gnal

(arb

. uni

ts)


CWCW--OSL from AlOSL from Al22OO33:C: LET dependence:C: LET dependence

0.1 1 10 100 1000

0.5

0.6

0.7

0.8

0.9

1.0

SU

V/ S

F-ce

nter

LET in water (keV/µm)


CWCW--OSL from AlOSL from Al22OO33:C: relative efficiency:C: relative efficiency

0.1 1 10 100 10000.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

η

LET in water (keV/µm)

Closed symbols: UVOpen symbols: F-center



(8) Possibility of extracting dose due to low LET from dose due to high LET 100 mGy beta 100 mGy He

3.16228 12.5893 50.1187 199.526 794.328DoseGy

0

2

4

6

8

10

g i

3.16228 12.5893 50.1187 199.526 794.328

3.16228 12.5893 50.1187 199.526 794.328DoseGy

0

2

4

6

8

10

g i

3.16228 12.5893 50.1187 199.526 794.328

3.16228 12.5893 50.1187 199.526 794.328DoseGy

0

2

4

6

8

10

g i

3.16228 12.5893 50.1187 199.526 794.328

3.16228 12.5893 50.1187 199.526 794.328DoseGy

0

0.5

1

1.5

2

2.53

3.5

g i

3.16228 12.5893 50.1187 199.526 794.328100 mGy C 100 mGy Fe

Dose distributionsextracted from deconvolutions ofOSL decay curves


RisoeRisoe TL/OSL readerTL/OSL reader


Experimental OSL readersExperimental OSL readers

Portable POSL system

Laboratory POSL system


Experimental OSL readersExperimental OSL readers

InLightTM (Landauer Inc.)

MicroStarTM (Landauer Inc.)


Current OSL applicationsCurrent OSL applications

LuxelTM badge

Personnel dosimetry of ionizing radiation (Landauer Inc.)(Technology licensed from OSU)

60,000 costumers (1.4 million individuals)

Al2O3:C from Landauer Crystal Growth Division (Stillwater)


• Project underway at the Environmental Measurements Laboratory(Gladys Klemic [email protected])

• Credit card format dosimeter• Strategically placed card

readers• Combine existing technology

in new design

Future projects: Future projects: The CitizensThe Citizens’’ DosimeterDosimeter

Requirements•Sensitivity between 0.5mGy – 10 Gy•Readout in <3s•Signal loss <10% relative to previous readout


Future projects: Future projects: The CitizensThe Citizens’’ DosimeterDosimeter

Objectives• Design and build a functioning prototype OSL reader

(light source, light transducer, associated electronics)• Operational in a bench-top setting, but components

chosen such that they could be incorporated into a rugged commercial version (that could be used in a sheltered outdoor environment).

• Design the coupling between a prototype card and the reader

• Design the prototype card


Mars Dating InstrumentMars Dating Instrument

Objectives• Design and build a

functioning prototype TL/OSL reader for luminescence dating of martian surface sediments.

• (light source, light transducer, associated electronics, radiation source)


Mars Dating InstrumentMars Dating Instrument


Space DosimetrySpace Dosimetry

Next step• OSL personal dosimeter readout capability for long-

duration missions (ISS, Moon, Mars)• Design and build a functioning prototype OSL reader

for on-board use (light source, light transducer, associated electronics, software)

• Design an astronaut personal dosimeter badge including capability for PNTD and TLD

• Design interface to the reader



Requirements• Sensitivity < 0.01 mGy• Days to years of accumulated dose (up to 3 year

missions)• Fast and easy readout• Dosimeter – easy to wear, use, handle, read• Light-weight, low power, etc.



Conclusions:• Fabrication of a small OSL reader will happen in the

next few years due to the convergence of interests in homeland security, planetary exploration, luminescence dating, and space dosimetry.

• All elements for the reader are available. There is no critical obstacle: OSL readout is already realized, electronics is feasible.


Thank you!Thank you!

Documents

Development of a portable OSL reader for spaceflight ......m H. 2. O) (1) OSL from Al. 2. O. 3. shows sensitivity to HCP of LET > 10 keV/µm (up to 290MeV/n Xe; 1047 keV/µm) (2) Sensitivity