Slide 1

Nuclear Reaction and Decay Data for Medium Energy Radionuclide Production

Jonathan W. Engle

Los Alamos National Laboratory, LA-UR 15-23573

Thursday, May 28th, 2015

Slide 2

Medium-Energy Radionuclide Production Context at LANL IPF

IPF at LANSCE

Beam Stop Line D

Line X

Line A 800 MeV Side Coupled Cavity Linac

805 MHz H+

H- Drift Tube Linac

201.25 MHz

100 MeV Transition Region

750 keV

H+

H-

H-

Proton Injectors

100-MeV IPF

SCCL is 90% of accelerator length

Proton Storage Ring

Weapons Neutron Research Facility

Manuel Lujan, Jr. Neutron Scattering Center

Unclassified  

Slide 3

Medium-Energy Radionuclide Production Context at LANL IPF

(p,xnyp) (p,αxn) (p,αxn)

(p,xn) (p,xn) (p,xn)

High Energy (93-70 MeV)

Medium Energy (65-40 MeV)

Low Energy (31-0 Mev)

3 Stack Target Irradiation 100 MeV H+

(240 µA limit)

Slide 4

Radionuclides of Interest at LANL Red for those with nuclear data being actively or recently pursued.

Isotope Half-life Main Use 82Sr 25.5 d Parent of 82Rb used in cardiac perfusion studies with PET 68Ge 270 d Parent of 68Ga being tested for diverse PET applications 22Na 2.6 a PET isotope used as a tracer and sources material 32Si 153 a Environmental tracer; produced in partnership w/ TRIUMF 73As 80.3 d Tracer for toxicology studies

109Cd 462.6 d Source for X-ray fluorescence 225Ac 10 d Alpha emitter used in cancer therapy clinical trials

186gRe 90.6 h Bone pain palliation, cancer therapy 44Ti 58.9 a Generator for PET isotope 44Sc

236Np 1.5 105 a Standard for Np quantification by IDMS 119Sb 38.5 h Auger emitter for cancer therapy

Slide 5

Summary

•  Nuclear Excitation Functions – Targeted measurements in the context of global isotope/data needs and existing production facilities

§  Needed to predict Yield and Impurities and to guide Target Design §  Needed to resolve discrepancies §  Useful for V&V of codes and nuclear models

•  The necessary quality and breadth of capabilities §  Accuracy in Standard Foil Stack Activation experiments

-  Energy and distribution, intensity… Analyzing magnets, Faraday cups -  Target characterization

–  Target preparation and pre/post-irradiation characterization –  Signal attribution due to overlapping gammas

§  Charged and neutral particles

•  Nuclear Decay Data

Slide 6

To Predict Yields and Impurities

232Th(p,x)225Ac 232Th(p,x)227Ac

Slide 7

To Predict Yields and Impurities

232Th(p,x)225Ac 232Th(p,x)227Ac

Slide 8

To Predict Yields and Impurities

0

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15

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30

35

40 60 80 100 120 140 160 180 200

Cros

s Sec

tion

(mb)

Energy (MeV)

Th-232(p,x)Ac-226ABLA+INCLCEM03.04BertiniTitarenko et al, 2003Gauvin et al, 1963This Work

0

5

10

15

20

25

30

35

40

20 40 60 80 100 120 140 160 180 200

Cros

s Sec

tion

(mb)

Energy (MeV)

Th-232(p,x)Ac-227ABLA+INCLCEM03.04BertiniErmolaev et al. 2012, αErmolaev et al. 2012, 159 keV γErmolaev et al. 2012, 100 keV γGauvin et al., 1963Lefort et al., 1961This Work

0

1

2

3

4

5

6

40 60 80 100 120 140 160 180 200

Cros

s Sec

tion

(mb)

Energy (MeV)

Th-232(p,x)Ce-139ABLA+INCLCEM03.04BertiniThis Work

0

10

20

30

40

50

60

40 60 80 100 120 140 160 180 200

Cro

ss S

ectio

n (m

b)

Energy (MeV)

Th-232(p,x)Ce-141 ABLA+INCLCEM03.04

BertiniTitarenko et al, 2003

Holub and Yaffe, 1973This Work

0

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10

15

20

25

30

35

40

40 60 80 100 120 140 160 180 200

Cros

s Sec

tion

(mb)

Energy (MeV)

Th-232(p,x)Ce-143

ABLA+INCLCEM03.04

BertiniTitarenko et al, 2003

Holub and Yaffe, 1973This Work

0

2

4

6

8

10

12

40 60 80 100 120 140 160 180 200

Cros

s Sec

tion

(mb)

Energy (MeV)

Th-232(p,x)La-140

ABLA+INCLCEM03.04

BertiniTitarenko et al, 2003

Holub and Yaffe, 1973This Work

0

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20

30

40

50

40 60 80 100 120 140 160 180 200

Cros

s Sec

tion

(mb)

Energy (MeV)

Th-232(p,x)Ba-140

ABLA+INCLCEM03.04

BertiniTitarenko et al, 2003

Holub and Yaffe, 1973Duijvestijn et al, 1999

This Work

226Ac 227Ac

139Ce 141Ce 143Ce

140La

140Ba J.W. Engle et al. Phys. Rev. C 88 (2013) 014604

J.W. Engle et al. (accepted to Radiochimica Acta)

Slide 9

To Guide Target Design Example: 75As(p,4n)72Se, natBr(p,x)72Se

Slide 9

0

20

40

60

80

100

120

140

160

30 50 70 90 Proton energy [MeV]

1979, T. Nozaki+

1988, A. Mushtaq+

75As(p,4n)72Se

0

2

4

6

8

10

12

14

10 30 50 70 90

Cro

ss se

ctio

n [m

b]

Proton energy [MeV]

2001,M.Fassbender+

2002,D.deVilliers+

natBr(p,x)72Se

Slide 10

New Measurements are Also Needed to Resolve Discrepancies

natSb(p,x)119gSb natSb(p,x)119mSb

Slide 11

Data as a Standard for V&V of Nuclear Codes

0.1

1

10

1007 Bei

46 Sci(m

+g)

48 Sci

59 Fec

74 Asi76 Asi77 Brc

82 Bri(m

+g)

86 Rbi(m

+g)

87 Yc

87m Y

c88 Y

i91 Sr

c95 Nb

i(m+g

)95 Tc

c*95 Zr

c96 Nb

i96 Tc

i(m+g

)99 M

oc

99m Tc

i(m)

100 Pd

c10

0 Rhc

103 Ru

c

Cros

s Sec

tion

(mb)

800 MeV p + 232Th

(a)This WorkTitarenko et al., 2003CEM03.03BertiniABLA+INCL

Slide 12

Data as a Standard for V&V of Nuclear Codes

0.1

1

10

100

7 Bei46 Sc

i(m+g

)48 Sc

i59 Fe

c74 Asi76 Asi77 Brc

82 Bri(m

+g)

86 Rbi(m

+g)

87 Yc

87m Y

c88 Y

i91 Sr

c95 Nb

i(m+g

)95 Tc

c*95 Zr

c96 Nb

i96 Tc

i(m+g

)99 M

oc

99m Tc

i(m)

100 Pd

c10

0 Rhc

103 Ru

c

Cros

s Sec

tion

(mb)

800 MeV p + 232Th

(a)This WorkTitarenko et al., 2003CEM03.03BertiniABLA+INCL

Assumed accuracy in code predictions for charged particle-induced reactions: •  Magnitude: Factors of 1-5 •  Structure: Within 10 MeV

Useful measurements will improve on this.

Slide 13

The Standard Stacked Foil Activation Method

1.  Activation of well-characterized thin samples

2.  Quantification of produced radioactive residuals

3.  Calculation of reaction probability

Slide 14

The Standard Stacked Foil Activation Method

•  Driving, Reported Uncertainties at Present: –  Incident particle flux during measurement: 4-12% –  HPGe Assay: 3-5% efficiency calibration. 1-3% peak fitting. –  Characterization of atomic density of irradiated sample: 1-?%

(challenging when not using metallic foils)

–  Peak deconvolution / Radionuclide identification: a problematic, systematic source of misattribution error

Combined Uncertainty is generally >6%.

Slide 15

Particle Intensity

•  Commonly tracked with monitor reactions, which lend their own uncertainty

27Al(p,x)24Na

Slide 16

A solution: Faraday Cups

•  Of course they have their own challenges: –  secondary electron suppression, –  target electrical insulation, –  particle and flux dependences are not

always simple

•  Alternative real-time, verifiable particle flux monitors

–  Offline-Faraday Cup calibrated SEEM or LEM

Slide 17

Primary Beam Energy

•  Energy degradation has a limited effective range, –  Commonly “verified” by monitor foils giving reactions with known

thresholds (indirect measurement), –  or calculated by established codes (computational)

0  

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30  

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40  

10   12   14   16   18   20   22   24  

TTL  ra7o

   

Proton  energy  [MeV]  

181/186g  

181/182g  

Slide 18

Tunable Beam Energies, Analyzing Magnets

Slide 19

Target Characterization

•  Some measurements are avoided because of the challenge of characterizing targets (e.g.,72Se) –  We need better ways to prepare them and measured mg/cm2

–  e.g.: XRF?

Sb Kα Cu Kα

•  Kα map shows very low intensity all around the edges of the foil Intensity decreases by a factor of ~2 in the green region relative to the blue

•  The unexpected presence of Cu lines reveals estimated 40-50% contamination from Cu

Slide 20

Residual Quantification

•  At higher energies, or for more massive target nuclei, spectral analysis is challenging

0

2

4

6

8

10

12

0 500 1000 1500 2000

log(

Coun

ts)

Energy (keV)

Example Spectrum of 800 MeV p + Th-232

Slide 21

Identification and Quantification of Residuals by Gamma-Ray Spectrometry

Slide 21 Slide 21

102

103

0 10 20 30 40 50 60 70 80

165.85 keV, 79.9%

cps

in P

hoto

peak

Time (d since EoB)

y = m1*exp(-ln(2)/137.64*x)ErrorValue

2.1422448.38m1 NA9635.4Chisq

NA0.85844R2

101

102

103

104

0 5 10 15 20 25 30 35 40

534.4 keV, 67.6%199.2 keV, 41.5%1222 keV, 31.3%

cps i

n Ph

otop

eak

Time (d since EoB)

y = m1*exp(-ln(2)/5.35*x)ErrorValue

10.4256710.7m1 NA17562Chisq

NA0.99962R2

Peak areas extracted from multiple recorded spectra

Decay of one gamma line followed over time to determine EOB activity

Decay of three gamma lines over time, providing three independent EOB activity measurements

One analysis cycle produces a single cross section data point

Slide 22

What is possible

10

100

1000

104

0 20 40 60 80 100 120

199Au, 117Sb, 123Te, 123I, 226Ac, and 117mSn Decay Curves

158 keV

cps

in P

hoto

peak

t (d since EoB)

y = m1*exp(-ln(2)/3.139*x)+m...ErrorValue

45.849618.47Au1996170.43.1092e+5Sb117

0.5868366.996Te123639.5716729I123233.57765.18Ac226

7.333870.33Sn117mNA106.69Chisq

NA0.99942R2

Slide 23

Neutral Particles

•  Neutrons (the very fast ones) •  Also for gammas

0.01

0.1

1

10 100

Cro

ss S

ectio

n (b

arns

)

Energy (MeV)

Zn-68(n,x)Cu-67

Experimental DataTENDL 2012TENDL 2011TENDL 2010JEFF-3.2

0.01

0.1

1

10 100

Cros

s Sec

tion

(bar

ns)

Energy (MeV)

Zn-67(n,p)Cu-67 Experimental DataTENDL 2012ENDF/B-VII.1ROSFOND 2010

Slide 24

Data to Buttress Capability Development at New Facilities

Slide 25

Nuclear Decay Data – An example

Measured BR Source

776.50 keV gamma of 82Rb

13.4 ± 0.5 % H.-W. Muller 1987 (extensively used)

15.08 ± 0.16 % J.K. Tuli 2003 & NNDC 14.93 ± 0.37% C.J. Gross et al., 2012

Slide 25

Slide 26

Thank you for your attention

Slide 27

Related initiatives Engagement in IAEA data evaluation efforts

•  Cross section measurement effort gained national and international attention

•  Invited to participate in an IAEA Consultants’ Meeting in 2011

•  Follow-up invitation to participate in a 3 year IAEA Coordinated Research Project starting in 2012 (11 countries represented)

•  First of three Research Coordination Meetings occurred in Dec 2012

•  Summary Report published in February 2013