Accelerator mass spectrometry (AMS) ‐ principles and some applications

Today’s lecture:

•Introduction to 14C and AMS – tandem-AMS versus single stage AMS (SSAMS)

I t d ti t li ti f AMS•Introduction to applications of AMS

•Instructions for your assignment: * literat re st d* literature study * preparing a scientific poster* oral presentation

We will decide topics, groups, deadlines and 

days for oral presentation today! 

Accelerator mass spectrometry (AMS) 

• Archeology

‐ principles and some applications

3H

cheology• Geology • Medicine

14C36Cl

3H • Food chemistry• Radiation protection• Ecology26Al

59Ni• Ecology• Radioecology•Aerosol science

Al

129I10B

•Microdosing

10Be

H i 14C d?How is 14C created?

O214CO2Modern carbon

Cosmic rays+ 14C (carbon-14)

O2

2

14CO2

2

14CO2 14C + O214CO2

99% 12C1% 13C

10-10% 14C

14N (nitrogen-14)

O2

O214CO2

2 2

14C 14N + -radiationT 5730T1/2=5730 years

How to measure 14C? (T1/2=5730 years)

”Modern”carbon:

How to measure  C? (T1/2 5730 years)

ode c bo :99% 12C1% 13C

Decay measurement:• several days of measuring time• 1 g carbon

14 decays/minute

10-10 % 14Cg

50 000 million atoms

14 decays/minute1 gram of modern carbon 14C 14N + -radiation

AMS measurement:AMS measurement:• < 1 hour of measuring time• 1 mg carbon

Why not conventional mass spectrometry?Why not conventional mass spectrometry?

BR=mv/q=(2mE)1/2/q

The 14C signal will drown in a background of interfering isobars

(i i h M 14 13CH)!(ions with M=14, e.g. 13CH)!

Accelerator Mass Spectrometry (AMS) removes isobars!

Ion source

Detector

The picture shows an example of a large 5 MV Tandem AMS system

New development: Si l S AMS (SSAMS) i d f T d AMSSingle Stage AMS (SSAMS) instead of Tandem AMS

We have SSAMS at Lund University

• Much smaller!• Much cheaper!• Much cheaper!

In your poster you should describetandem AMS 

orsingle stage AMS (SSAMS)single stage AMS (SSAMS).

You should also select an application of AMS to present.

Tandem-AMSTandem-AMS

Ion sourcewith carbon

3 MV tandem accelerator

Velocitywith carbonsamples

Dipolmagnets

Velocityfilter

Particledetector

Mass separator

detector

• Measures 14C/12C: gives activity ( age)• Measuring time: ca 20 min/sample• Detection limit: <1 attomole (10–18 mole) 14C• Sample size: 10 g 1 mg carbon• Sample size: 10 g - 1 mg carbon

Tandem‐AMS – removal of isobarsBR=mv/q=(2mE)1/2/q

14C3+

14Cq+14C–

12C–

13C–Cq ,

13CH+, 13CH2+

No 13CH3+

hi h !

C13CH–

12CH2–

14C–

13CH–

12CH2–

Important properties:

or higher! CH2No 14N!

Important properties:•Negative ion source: suppresses certain atomic isobars (14N)•Stripping process: breaks up molecules•High energy: every particle can be identified

Single Stage AMS (SSAMS)Single Stage AMS (SSAMS)The system we have at Lund University

250 kV acceleration

He (or Ar) gas stripperChanges charge state from negative to positive

Dipole

accelerationg g f g pBreaks up all molecular isobars (e.g. 13CH in the 14C beam)

Dipolemagnet, 

Switches 12C / 13C / 14Cl / 2

Dipole

Electrostatic

Selects m.E/q2magnet,Selects m.E/q2

q=+1 FaradayAnalyzer (ESA)Acts as a switch between 

the two ion sources

q +1 ycups

Measure 12C +, 13C +the two ion sources

Selects E/q

,

Electrostatic Detector

Ion sources –Analyzer (ESA)

Selects E/q

DetectorMeasures 14C+

Ion sources produce negative ions (q=‐1)from one of the ion sources

Ion source wheel for 40 carbon samplesfor 40 carbon samples

Sample holdersSample holders with carbon samples

Cs sputtering ion source – producing singly charged negative ions

He (or Ar) stripper

250 keV

stripper

250 keV acceleration tube

Electrostatic

Ion source

Electrostatic analyser

Control room

Applications of AMSNatural 14C

O214CO2Modern carbon

Cosmic rays+

14N14C

O2

2

14CO2

2

14CO2 14C + O214CO2

99% 12C1% 13C

10-10% 14C

14N

O2

O214CO2

2 2

14C 14N + -radiationT 5730T1/2=5730 years

14C in atmospheric CO until today14C in atmospheric CO2 until today…

Something drastic happened

800

g ppin the 1900’s!600

(‰)

400

14C

(

n + 14N→ 14C + p

0

200 14C+O2→ 14CO2

-25000 -20000 -15000 -10000 -5000 0 5000

0

Calendar year

14C in atmospheric CO (clean air)C in atmospheric CO2 (clean air)year 1900‐2007 14C-specific

ti it800 INTCAL98

V t CO

activity

Absorption in 400 Bq/kg

600

Vermunt, CO2 Schauinsland, CO2 Måryd, Juncus

‰)

biosphere and oceans

400

14C

(‰

Bomb-effect300 Bq/kg

200Combustion of fossil fuels

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

0fossil fuels 226 Bq/kg

Calendar year

14C in atmospheric CO (clean air)C in atmospheric CO2 (clean air)year 1900‐2007 14C-specific

ti it800 INTCAL98

V t CO

activity

400 Bq/kgb l

600

Vermunt, CO2 Schauinsland, CO2 Måryd, Juncus

‰)

Bomb‐pulsedating

400

14C

(‰

300 Bq/kg200

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

0 226 Bq/kg

Calendar year

Bomb 14C – some applicationsBomb‐14C – some applicationsUptake in biosphere and oceans

Studies of 

Uptake in biosphere and oceans

• the carbon cycle• turnover times in biological 800 INTCAL98

tissues

400

600

Vermunt, CO2 Schauinsland, CO2 Måryd, Juncus

4 C (‰

)

Dating- forensic science0

200

1

- retrospective cell dating in man1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Calendar year

B b 14C li iBomb‐14C – some applications

Checking vintages of wine Tracking narcotics

Z i 2004Identification of furs 

Burchuladze et al, 1989Zoppi et al, 2004

Zoppi, 2004 of illegaly hunted animals

Geyh 2001Geyh, 2001

Bomb‐14C – some applications…

Growth rate

pp… in man

Growth rate of gallstones

Druffel & Mok, 1983

Age of senile plaques in Alzheimer’s disease

Lovell et al, 2002

Retrospective cell dating in the brain

Spalding et al, 2005

Dynamics of fat cell turnover

Spalding et al 2008Spalding et al, 2008

Carbon turnover in the human eye lens crystallines

Lynnerup et al, 2008 Dating of blood vessel plaquesGoncalves et al, 2010

Are there some more localvariations?

Natural 14C Bomb‐14C

What influences the contemporary 14C specificcontemporary  C specific 

activity???C l fi d l t

Volcanoes

Coal fired power plants

Fossil carbonTraffic

Fossil carbon

Nuclear power generates14C!Nuclear power generates14C!Generator

Steam

Turbine

Generator

Fuel

SteamCondensor

Sea waterFuel rods

Sea water

Reactor water

Nuclear power‐14Cp14C is produced in

14CO • the fuel• reactor water• construction materials

14CO2

Waste

14C SFR

14CWaste disposal facility

Nuclear power‐14C indeedi l l14C i igives local14C‐variations…

in the vicinity of a i l freprocessing plant for 

spent nuclear fuel

1200

800

1000Grass 1,5 km from Sellafield,UK

rmill

e)

447 Bq/kg C

400

600

14C

(per

0

200

226 Bq/kg C1940 1950 1960 1970 1980 1990 2000 20100

Calender year

226 Bq/kg C

Aerosols and their effects

lightscattering5-10 µm scattering

lightabsorption

5-10 µm

3-5 µm

heat radiation

µ

2-3 µm

1-2 µm

0 1 1 µmCloudformation

0.1-1 µm

http://www.stadt-

Aerosols can affect: human health

http://www.stadtzuerich.ch/gud/de/index/umwelt/luft/schadstoffe/feinstaub.html

the Earth‘s climate

Where do the carbonaceous aerosol stem from?

No 14CContemporary 14C/12C ratios12

12

14

12C/ C ratios12

Millions of years ago

Recently

14C decay

Accelerator mass spectrometry - Some more applications

• Cosmic rays

26Al

Cosmic rays• Solar activity• Earth magnetic field• Meteorites26Al

7Be14C

36Cl

3H

59N

• The moon• The atmosphere• The climate

10Be

Cl63Ni

59Ni

41Ca

• Glaciers• Oceanography• Medicine

129IC

• Biology• Archeology• Geology

N l h i• Nuclear physics• Material science• Radiation protection• R di l• Radioecology• ...

Literature study, poster and oral presentation on AMS

The assignment includes: lit t t d• a literature study, 

• preparing a poster,p p g p ,• an oral presentation (about 10 minutes) and 

l f h d ’• an oral opposition on one of the co‐student’s posters (about 5 minutes).  

Th k i f d i iThe work is performed in pairs. 

Possible topicsChoose one of the following suggestions of AMS applications, or 

make a suggestion of your own (see e.g. in the paper by Fifield)

AMS in archaeology • Cosmic ray studies and calibration in radiocarbon dating

l• AMS in geology• AMS in oceanography• AMS in glaciology• AMS in glaciology• Extraterrestrial applications of AMS• AMS in medical technology (e.g. microdosing and mass balance gy ( g g

studies) • AMS for studies in occupational medicine  • Bombpeak dating (e g forensic science regenerative medicine)• Bombpeak dating (e.g. forensic science, regenerative medicine)• AMS in aerosol science• 14C from nuclear powerp• 14C in source apportionment of atmospheric aerosol

The poster: a (scientific) seduction operation!!!

- One should understand immediately what your poster is aboutposter is about

Message clear and quickly visibleKey ideas (only the essential)Key ideas (only the essential)Logical organisation of the poster

- Goal: to attract people and make them curious!

Eye-catching titley gVisual layoutPictures and figures preferably to textT t f t bi h t b d ilText font big enough to be read easilyfrom a distance

Check‐list for a good poster1. OverviewIs the poster eye-catching?Are the structures and optical elements helpful in guiding you through the poster?Is there an overriding logical concept underpinning the structure of the poster?

2. Take home messageIs the main message immediately visible?Is the relevance of the problem immediately visible?

3 T t3. TextIs the text on the poster inviting to read?Is the text well compressed to the essentials?Is the language simple and clear?Is the language simple and clear?

4. Figures, GraphsAre the figures and Graphs on the poster inviting to read?Are the figures and Graphs on the poster inviting to read?Are the Legends clear and helpful?Are the graphs or tables essential for the poster?

5. InteractionDoes the poster make me feel like discussing with the author?

Each poster should include:ac poste s ou d c ude:

A i t titl• An appropriate title• Names of authors• Affiliations of authorsAffiliations of authors• The following sections  

Introduction (in this section you provide an adequate background and state the objectives of the study)Accelerator mass spectrometry (this is the Method section where you  describe the principle of the AMS: tandem AMS or SSAMS, preferably withdescribe the principle of the AMS: tandem AMS or SSAMS, preferably with pictures)“Your topic” (here you describe your topic with proper references)Summary and conclusions

• References at the end of the poster (see previous slide)

Literature suggestions to begin with gg g(find the articles at the web in through the library)

H llb R Sk G A lHellborg R, Skog G: Accelerator mass spectrometry. Mass Spectrometry Reviews 27 (2008) 398‐427.

Fifield KF: Accelerator mass spectrometry and its applications. Reports on Progress in Physics 62 (1999) 1223‐1274.

K Stenström, M Sydoff, S Mattsson: Microdosing for early biokinetic studies in humans. Radiation Protection Dosimetry 139 (2010) 348‐352,doi:101093/rpd/ncq029 y p q

You may need further references for your specific topic. If you need help, contact Nolwenn (nolwenn.perron@nuclear.lu.se, office: B216)

References in the poster (not more than 10!)

Example: 

Reference to a paper by Purser and co‐authors, published in 1977. p p y p“One important discovery was that 14N does not form negative ions (Purser et 

al., 1977).”

References are alphabetically ordered in the following format:Authors. Publishing year. Title of paper. Journal title journal number: page 

bnumbers.

Purser KH, Liebert RB, Litherland AE, Benkens RP, Gove HE, Bennett CL, Clover MR, Sondheim WE 1977 An attempt to detect stable N‐ ions from a sp tter ion so rceSondheim WE. 1977. An attempt to detect stable N‐ ions from a sputter ion source and some implications of the results for the design of tandems for ultra‐sensitive carbon analysis. Rev Phys Appl 12:1487–1492.

Include references and do not copy what anyone else has written(produce your own text from the knowledge you gain when reading articles etc). This is very important (copying someone else’s text is considered as cheating).

URKUNDURKUND• All posters should be submitted to URKUND to protect your 

d h ´ i h !own and others´ copyrights! • Include references and

f dFor information and instructions, see

http://www.urkund.com/int/en/student_information.aspand http://www.urkund.com/int/en/student_gorsahar.asp

Posters should be submitted to Nolwenn´s URKUND address: nolwenn.perron.lu@analys.urkund.se

http://www.urkund.com/int/en/student_information.asp

http://www.urkund.com/int/en/student_gorsahar.asp

Important datesT d• Today:– find someone to work with, – make your choice of topic and tell Nolwenn, preferably before the end of themake your choice of topic and tell Nolwenn, preferably before the end of the 

class, or email to nolwenn.perron@nuclear.lu.se. 

• 13 February:13 February:– Deadline for poster submission to Nolwenn (nolwenn.perron@nuclear.lu.se)– Deadline for poster submission to URKUND 

( )(nolwenn.perron.lu@analys.urkund.se)

Comments will be made and groups have the possibility to send a modifiedversion until the 16 Februaryversion until the 16 February

• 16 February: Nolwenn distributes posters for opposition

• Week beginning 20 February: – Oral presentation and opposition (Decide date today!)– Times decided: Tue 22/2 13-15 (room H422)

Pl lli dPlease use spelling and grammar check beforegrammar check before submitting the poster!!!submitting the poster!!!