Diamond for actinides detection and spectroscopy in liquids

Diamond foractinide tracesdetection and

spectrometry inliquids

Michal Pomorski

Intoduction

The Actinides

Detection ofActinides

Results andDiscussion

ImmersedDetectors -State of the Art

Sensors andElectroprecipita-tion

SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors

Conclusions andPerspectives

Diamond for actinide traces detection andspectrometry in liquids

Michal Pomorski

Diamond Sensors Laboratory, The French Atomic Energy Commission (CEA),LIST Institute, France

June 14, 2013

ANIMMA 2013 Conference, 23-27 June 2013, Marseille, France



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Co-Authors, Co-Workers

Christine Mer

Jacques de Sanoit

Thuan-Quang Tran

and Philippe Bergonzo

Acknowledgments:

Laboratoire National Henri Becquerel,CEA-Saclay

Trace alpha-particle detection system for waternetworks: from direct detection in liquid phaseto identification

EU French-German project with 1.4M¿budget

IAF Freiburg, ICT Karlsruhe

Karlsruhe

France, Germany GmBH



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Outline

1 IntoductionThe ActinidesDetection of Actinides

2 Results and DiscussionImmersed Detectors - State of the ArtSensors and ElectroprecipitationSensors PerformanceIn-situ SpectroscopyStabilityLimiting Factors

3 Conclusions and Perspectives



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


The Actinides

15 metallic chemical elements with atomic numbers from 89 to 103

U and Th occur naturally in substantial quantities, the other actinides are purelysynthetic elements (produced in nuclear plants, nuclear weapons tests)

all actinides are radioactive elements (mostly long-lived; α decay)

major use: nuclear fuel (235U, 239Pu), nuclear weapons (239Pu), minor use eg. powergenerators for space crafts

in the past also some less serious eg.: smoke detectors 241Am, thorium dioxide lensescoating (eg. Pentax Takumar)



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Detection techniques

nuclear waste accidents criminal/terrorist acts

Detection techniques

radiometric techniques (short lived)

α particle spectroscopyγ/X spectroscopyliquid scintlliation counting

mass spectrometry ICP (long lived)

non of these are easy to operate portable systems

Some numbers 1Bq in 1l liquid

actinide life time [y] α energy [MeV] number of atoms / cm2

239Pu 24110 5.157 1.1x109

241Am 433 5.468 2.0x107

244Cm 18 5.804 8.3x105



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Classical α particles spectroscopy

well known and discrete α-particle energies for each actinide (identification), 3 - 8 MeVenergy range - large signals easy to detect ... but short range in solid and liquis - tens ofmicrons

Energy loss (straggling):

radionuclide matrix

inter-medium

detector entrance electrode

detector interaction:

ionization (e-h pair creation)

charge transport (drift-diffusion)

readout electronics:

intrinsic noise

noise related to detector (leakagecurrent, capacitance)

relative energy resolution of common vacuum systems ∆EFWHM/E 0.2% - 0.3%



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Immersed Detectors - State-of-the-Art

Corrosion hard CVD diamond alpha particle detectors for nuclear liquid source monitoring, P. Bergonzo et al., Diamond andRelated Materials 9 (2000) 10031007

Direct measurement of alpha emitters in liquids using passivated ion implanted planar silicon (PIPS) diode detectors, O.B. Egorov

et al., Nuclear Instruments and Methods in Physics Research A 537 (2005) 600609



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Electrochemically assisted alpha particle detector

The idea

first pre-concentrate the actinides on the entrance electrode using electrochemistry

measure in-situ using standard alpha spectroscopy chain

in future: why not to combine both for dynamic study

Active volume:

high resistivity silicon wafer - counting only

silicon PiN diodes (PIPS in the future) - spectroscopy

Entrance electrode (electrochemically active)

BNCD metallic doping [B] 1021 at.cm3

thickness: 200-400 nm



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Electrodeposition ?

Actinides under a cationic form in aqueous solutionFirst thought: electrodeposition by reduction at cathode

M+3 + 3e → M0

The standard reduction potential of some actinides

Uranium: U3+/U E0 = -1.64 V/ENH

Neptunium: Np3+/Np E0 = -1.76 V/ENH

Plutonium: Pu3+/Pu E0 = -2.00 V/ENH

Curium: Cm3+/Cm E0 = -2.04 V/ENH

Americium: Am3+/Am E0 = -2.07 V/ENH

-2 -1 0 1 2-0,10

-0,05

0,00

0,05

0,10

0,15

B-NCD

I (m

A)

E (V/AgAgCl)

H2O + H+ + 2 e −→ H2 + OH−

M3+ + 3OH− −→ M(OH)3



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Electrodeposition Electroprecipitation

Parameters adopted from radioactive sourcepreparation on stainless steel disks:

pH 3-4

0.3M Na2SO4 electrolyte

current -1.5 < J < -5 mA/cm2

magnetic stirring 1000 rpm

time 90 min

basified to pH=10

By reversing the current (10 min, 5mA),actinides are released to solution - sensorsdecontamination

Na2SO4 = 0.3 M, pH 4 + phenolphthalein,

J= -5 mA/cm2



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Detection Performance

counting-grade sensor with high resistivity Si as detector’s active volume

from 0.6 Bq to 29 Bq 241Am (α 5.486 MeV) in 100 ml solution (0.006 - 0.29 Bq/ml)

precipitation time 1.5h, acquisition time 1h

detector bias HV=0 (charge diffusion few µs)

precipitation efficiency 12% - 14 %

relative energy resolution ∆EFWHM/E > 10 %

decontamination efficiency 99.7%



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


In-situ Spectroscopy

spectroscopic-grade sensor with PiN Si diode as detector’s active volume

5Bq of 239Pu, 6 Bq of 243Am and 4 Bq of 244Cm in 15 ml solution, electrode surface0.9 cm2

precipitation time 1.5h, acquisition time 24 h

detector bias HV=0V (charge diffusion few µs)

0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 005 0 0

1 0 0 01 5 0 02 0 0 02 5 0 03 0 0 03 5 0 0

2 4 4 C m ( a 5 . 8 6 M e V )D E F W H M / E = 2 . 3 %( 1 3 5 k e V )

2 3 9 P u ( a 5 . 1 3 9 M e V )D E F W H M / E = 3 . 4 %( 1 7 5 k e V )

coun

ts

A D C c h a n n e l ( a . u . )

2 4 1 A m ( a 5 . 4 8 6 M e V )D E F W H M / E = 2 . 8 %( 1 5 4 k e V )

precipitation efficiency 14%

relative energy resolution∆EFWHM/E = 3.4% - 2.3%




Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


In-situ Spectroscopy

spectroscopic-grade sensor with PiN Si diode as detector’s active volume

5Bq of 239Pu, 6 Bq of 243Am and 4 Bq of 244Cm in 15 ml solution, electrode surface0.9 cm2

precipitation time 1.5h, acquisition time 24 h

detector bias HV=0V (charge diffusion few µs)

0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 005 0 0

1 0 0 01 5 0 02 0 0 02 5 0 03 0 0 03 5 0 0

2 4 4 C m ( a 5 . 8 6 M e V )D E F W H M / E = 2 . 3 %( 1 3 5 k e V )

2 3 9 P u ( a 5 . 1 3 9 M e V )D E F W H M / E = 3 . 4 %( 1 7 5 k e V )

coun

tsA D C c h a n n e l ( a . u . )

2 4 1 A m ( a 5 . 4 8 6 M e V )D E F W H M / E = 2 . 8 %( 1 5 4 k e V )

precipitation efficiency 14%

relative energy resolution∆EFWHM/E = 3.4% - 2.3%




Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Sensor Stability

241Am α-particles spectra for firstand 30th experiment

0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 00 , 0 0

0 , 2 5

0 , 5 0

0 , 7 5

1 , 0 0

1 s t e x p e r i m e n t a f t e r 3 0 c y c l e s

p r e c i p i t a t i o n / d e c o n t a m i n a t i o n

coun

ts (no

rmaliz

ed to

max

.)

A D C c h a n n e l ( a . u . )

2 4 1 A m 5 . 4 8 6 M e V α- p a r t i c l e s

No visible degradation in:

precipitation efficiency

position of the peak (signalamplitude)

shape of the spectrum

BNCD electrode after 70cycles

Metal (Pt) electrode after0.5 cycle



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Limiting factors for in-situ spectroscopy

Spectrum and map of 241Am precipitated on a BNCD electrode taken with an externalspectroscopy chain in vacuum

950 975 1000 10250

2000

4000

6000

co

unts

channel number [au]

241Am (main α 5.486 MeV)

∆E/E=0.25%(13.5 keV)

Intrinsic ∆E limitation due to the entrance BNCD electrode thickness (SRIM simulation)

4,50 4,75 5,00 5,25 5,50 5,750

100

200

300

400

500

600

700 Entrance electrode thickness:

400 nm BNCD 50 nm BNCD

Cou

nts

energy deposited [MeV]

0 50 100 150 200 250 300 350 400 4500

20

40

60

80

FW

HM

[keV

]

BNCD thickness [nm]

vacuum systems



Michal Pomorski

Intoduction

The Actinides





SensorsPerformance

In-situSpectroscopy

Stability

Limiting Factors


Summary and Outlook

It is possible to directly perform α-particles counting and energy loss spectroscopy in liquidsusing electrochemically assisted BNCD diamond/silicon sensors:

electroprecipitation efficiency 12-14 % (electrode surface tested max 0.7 cm2 -

commercial PIPS Canberra up to 12 cm2)

linear response with relative energy resolution of ∆E/E 3.4% - 2.3% measured directlyin solution (0.2-0.3 % for vacuum systems)

easy and efficient sensors’ decontamination

no degradation of the sensors after dozens of cycles

sensors compatible with existing α-spectroscopy electronics

device engineering: super-thin BNCD layers on PIPS detectors

improvement of the electrochemical methodology: parameters optimization fordiamond (see poster by Thuan Tran)

cleaning procedures: in-flow interferents’ separation

portable complete system as a demonstrator

Diamond for actinides detection and spectroscopy in liquids

Documents

Transcript of Diamond for actinides detection and spectroscopy in liquids