1. Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Preliminary tests for actinide measurements using AMS at the 1 MV Tandem accelerator
D. G. PACESILA1,2, T. B. SAVA1, M. STRATICIUC1, D. G. GHITA1, V. MOSU1
* PhD Student,
1. Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Magurele, Romania
2. University POLITEHNICA of Bucharest, Bucharest, Romania

2. Department of Tandem Accelerators
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Why AMS?
The most sensitive isotope selective detection method:
Single ion detection capabilities
High accuracy (few ‰)
Huge dynamic range
Extreme sensitivity
Sample:
Isotope ratios:
Typical size: mgμg
104millions of atoms
Accelerator mass spectrometry (AMS) is a technique for measuring long-lived radionuclides that occur naturally in our environment. AMS uses a particle accelerator in conjunction with ion sources, large magnets, and detectors to separate out interferences and count single atoms in the presence of 1 x 1015 (a thousand million million) stable atoms.
- important AMS radionuclides 10Be, 14C, 26Al, 36Cl, 41Ca, 129I, actinides, Half-life: yrs

3. Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
1 MV AMS block diagram:
negative ion source; 2. electrostatic analyzer on low energy; 3. analyzing magnet on low energy; 4. Q-pole lens ; 5. tandem accelerator;
6. analyzing magnet on high energy; 7. Beam current measurement sistem; o electrostatic analyzing on high energy;
9. gas ionization detector (E-ΔE )

4. AMS aplications at the 1 MV accelerator @ IFIN-HH RoAMS laboratory
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
AMS aplications at the 1 MV IFIN-HH RoAMS laboratory
More than 500 samples measured only this year.

5. Stable izotops ratio / radio-izotops in nature
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Aplications of the AMS method
Stable izotops ratio / radio-izotops in nature
Element
Izotop
Abundance(%)
Half-life(years)
Berilium
9Be
10Be
100
1.39x106
Carbon
12C
13C
14C
98.9
1.1
5.73x103
Aluminium
27Al
26Al
Clor
35Cl
36Cl
37Cl
75.77
24.23
3.01x105
Calcium
40Ca
41Ca
42Ca
96.941
0.647
1.04x105
Iodine
127I
129I
1.70x107
Uranium
238U
235U
234U
99.275
0.72
0.006
4.47x109
7.04x108
Plutonium
239Pu
240Pu
242Pu
2.40x104
6.56x103
3.74x105
Geology
Arheology/Geology/
Environment
Geology /Medicine
Geology
Medicine /Pharmaceutical
Oceanographic tracer, atmospheric and environment
Environmental supervision, Nuclear Forensics

6. Why are important actinide measurements?
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Why are important actinide measurements?
Nuclear materials
Finding evidence of the source, the trafficking, and the enrichment of the material.
In order to determine the production date (age dating, time since last purification) of a radioactive material for nuclear forensic and safeguards purposes, we have to be able to measure the ratios between U, Pu and Th isotopes.
Environmental samples
Nuclear processes emit trace amounts of material to the environment.
The nuclear material can settle on equipment and surfaces within buildings and can be transported outside to deposit on vegetation and soil or reach water systems.
Levels of certain fission products, Actinides and other radioactive species can be used as indicators of undeclared nuclear facilities or activities, either on-going or in the past
Nuclear material is everything that contains
U, Pu, Th.

7. Department of Tandem Accelerators
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Plutonium production
UO2 fuel
U isotopes - 232, 233, 234, 235, 236, 238
Plutonium isotope ratios (240Pu/239Pu) indicate the fuel burn-up
Sample used:
STD1/2 CNA-Pu:
239Pu/242Pu = 0,534±0,011
240Pu/242Pu = 0,281±0,005
Sample cathode

8. Department of Tandem Accelerators
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Experimental Set-up
Isotopes
Rare isotopes Pu, 240Pu, 242Pu
Stable isotopes no stable isotopes
Ion source
Sample material PuO
Target voltage kV
Extraction voltage 28 kV
Ionizer current A
Cesium temp o
Bouncer injection
Injected beam PuO-
ESA kV for 35 keV
X slit 1(esa) 5mm
Magnet current UO16
Bounced masses AMU AMU AMU
Bouncer voltage 1) 137 V ) V 3) V
X slit 2(magnet) 3mm
Accelerator
Injected masses AMU AMU AMU
Terminal voltages 1) kV 2) kV 3) kV
Stripper gas 6 μbar
High energy spectrometer
Charge state 3+
Yield 20%
Magnet current A for 240Pu
Rare isotope beam line
X slit mm
ESA voltages 1) kV 2) kV 3) kV
ESA exit slit fully retracted
Detector
Entrance window 75 nm silicon-nitride
Pressure mbar

9. Department of Tandem Accelerators
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Results
channel
counts
channel
counts
242Pu
channel
counts
channel
counts
240Pu
channel
counts
channel
counts
239Pu

10. Department of Tandem Accelerators
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Results
channel
counts
240Pu
160Dy
E. Chamizo et al., Nuclear Instruments and Methods in Physics Research B 266 (2008) 4948–4954
Isotopic Ratios
1 IFIN-HH
239Pu/242Pu = 0,5942
240Pu/242Pu = 0,2313
sTD CNA-Pu
239Pu/242Pu = 0.534
240Pu/242Pu = 0.281
E.C. Calvo et al., Nuclear Instruments and Methods in Physics Research B 361 (2015) 13–19

11. Conclusions and future perspectives
Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)
Department of Tandem Accelerators
Conclusions and future perspectives
The 1 MV HVEE AMS facility has been set-up for the measurement of plutonium isotopes. In terms of detection limits and optical transmission through the accelerator, the system compares to the other compact AMS facility ;
These results are very encouraging regarding the measurements of other actinides (236U,234U, 232Th,).
Our future prospects are:
Study of the sample preparation techniques;
Improvements on the performance of the ion source and on the detection setup;
Implementation of the He gas as stripper for a better transmission.

12. Thank you for your attention!