CIRCE, Dipartimento di Matematica e Fisica, Seconda Università di Napoli e INNOVA

filippo.terrasi@unina2.it

CIRCE anno decimo

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CIRCE anno decimo.

• The Center for Isotopic Research on Cultural and Environmental heritage, operated by DMF-SUN for INNOVA Scarl, is performing since 2005 both basic research and commercial and R&D activity in the field of applied nuclear physics.

• It features a 3 MV tandem accelerator, manufactured by NEC (WI-USA), including two Cs sputtering ion sources (one for stable and another for radioactive beams), an injector featuring an electrostatic analyzer and a magnet equipped with a fast bouncing system, a pelletron two-stage accelerator, a high-energy double focusing magnet and a spherical electrostatic analyzer. A switching magnet drives the beam in one of the 5 beam lines, each equipped with different experimental systems.

• The accelerator is used both for producing intense reaction-inducing ion beams and for ultrasensitive Accelerator Mass Spectrometry of several long-lived cosmogenic isotopes.

• The talk will present the ongoing research activity in archaeometry by both high-precision radiocarbon dating and Isotope Ratio Mass Spectrometry. The interplay between basic and applied research and customer service will be discussed highlighting interferences and synergies.

Circe and Odysseus

Κίρκη

Island of Eea

Dosso Dossi (Giovanni di Niccolo Luteri)

"Circe", c. 1522-1524, canvas, Galleria

Borghese, Rome

Centro Regionale di Competenza per lo “Sviluppo e il Trasferimento dell’Innovazione Applicata ai Beni Culturali e Ambientali”

Centro per lo Sviluppo ed il Trasferimento

dell'Innovazione nel Settore dei Beni

Culturali e Ambientali – INNOVA Scarl

2002

2011

“Core business”: ● 14C dating in archaeology and earth science

• Other isotopic methodologies for environmental and cultural heritage

• Other applications of AMS and Ion Beams in basic and applied physics and industrial research

Center for Isotopic Research on Cultural and Environmental heritage

Handled by DMF-SUN

CRdC INNOVA - INNOVA Scarl: Missione • Mettere a sistema eccellenze frammentarie e scoordinate • Favorire l’incontro tra domanda (dalle imprese) e offerta (dalla ricerca) di innovazione

Soci partecipanti: • Università di Napoli Federico II • CNR • Seconda Università di Napoli • Univerità di Salerno • Università di Napoli l’Orientale • Università di Napoli Parthenope

Consiglio di Amministrazione

Comitato di Coordinamento dei Poli: • Ingegneria per i beni culturali: • Restauro dell'architettura, diagnostica dei geomateriali e prospezioni: • Servizi integrati per l'archeologia e per l’ambiente • Informatica per la rappresentazione del territorio e l'archeologia • Sistemi informativi per i beni culturali - laboratorio pluritematico di diagnostica avanzata

ADVANCED DIAGNOSTICS PLURITHEMATIC LABORATORY AIR CONDITIONING SYSTEMS FOR MUSEUM APPLICATIONS: ASSESSMENT OF EFFICIENCY AND COMPLIANCE WITH REGULATIONS ANALYSIS AND DIRECT INSRUMENTAL DETECTION OF ARCHITECTURAL AND ARCHAEOLOGICAL STRUCTURES ARCHAEOLOGICAL HERITAGE CONTEXTUALISATION DAMPNESS IN BUILDINGS: DIAGNOSIS AND PROPOSALS FOR ACTION DATING USING AN ULTRASENSITIVE ACCELERATOR MASS SPECTROMETRY SYSTEM DESIGN AND DEVELOPMENT OF GEOGRAPHIC DATABASES DIGITAL MAPPING FROM SATELLITE IMAGES ENVIRONMENTAL DATA MONITORING SERVICES FOR LAND MANAGEMENT AND NATURAL HERITAGE CONSERVATION EVALUATION AND DIAGNOSIS OF POSSIBLE MALFUNCTIONS IN ARTIFICIAL LIGHTING SYSTEMS AND NATURAL LIGHTING SYSTEMS FOR CULTURAL HERITAGE GEOARCHAEOLOGICAL SURVEY GEOPHYSICAL SURVEYS IN UNDERWATER ARCHAEOLOGY IMAGE ACQUISITION AND PROCESSING FOR CULTURAL HERITAGE INFRARED REFLECTOGRAPHY (IRR) INNOVATION DIFFUSION AND INTEGRATION INTEGRATED ESEM MICROSCOPY AND EDS WITH SUPERCONDUCTING DETECTOR INTEGRATED SERVICES FOR PREVENTIVE ARCHAEOLOGY INTEGRATED SYSTEM CONSISTING OF FOURIER TRANSFORM INFRARED (FT-IR) SPECTROMETER AND FTIR MICROSCOPE INTERFEROMETRY AND HOLOGRAPHY IN THE DIAGNOSTICS OF THE STATE OF CONSERVATION OF ARTWORKS AND ARCHAEOLOGICAL FINDS ISOTOPIC METHODS FOR ARCHAEOLOGY AND THE ENVIRONMENT LABORATORY OF TERRITORIAL CARTOGRAPHY: A TOOL FOR ENVIRONMENTAL MONITORING AND ANALYSIS LASER CLEANING/ABLATION SYSTEM MICROCLIMATE FOR HERITAGE CONSERVATION: ANALYSIS AND CONTROL MOBILE ENVIRONMENTAL MONITORING LABORATORY MOBILE LABORATORY FOR SAFETY, CONSERVATION AND PROMOTION OF THE BUILT HERITAGE MOBILE LABORATORY OF GEOPHYSICAL PROSPECTIONS FOR ARCHEOLOGY MONITORING AND CONTROL OF ARCHAEOLOGICAL SITES MORPHOMETRIC ANALYSIS MULTITHEMATIC LABORATORY OF DIAGNOSTIC SURVEYS AND TECHNIQUES FOR CULTURAL HERITAGE RESTORATION AND CONSERVATION PALAEOENVIRONMENTAL RECONSTRUCTIONS FOR ARCHAEOLOGICAL HERITAGE PALAEONTOLOGICAL AND PALAEOECOLOGICAL ANALYSIS SCANNING MAGNETIC MICROSCOPY WITH SQUID SUPERCONDUCTING SENSORS SEDIMENTOLOGY LABORATORY SERVICES FOR THE PRODUCTION OF HISTORICAL ARCHIVES SETTING UP MULTIDISCIPLINARY EDUCATIONAL PATHWAYS: CONTRIBUTIONS TO DEVELOPING CULTURAL TOURISM IN THE CAMPI FLEGREI SOIL QUALITY MONITORING LABORATORY SPECIALIST CONSULTANCY SERVICES FOR ESTABLISHING PARKS, PROTECTED AREAS AND NATURE TRAILS STRUCTURAL DIAGNOSTICS FOR THE BUILT HERITAGE STRUCTURE AND DEFECT ANALYSIS USING THERMAL IMAGING SUITE OF CONSERVATION AND PROMOTION SERVICES FOR INSTALLATIONS IN NATURAL HISTORY MUSEUMS, SHOWS, EXHIBITION SPACES; IMPLEMENTATION OF SERVICE CENTERS FOR LAND QUALITY ENHANCEMENT; PUBLISHING AND MULTIMEDIA PRODUCTS; TRAINING AND PROFESSIONAL UPDATING; EDUCATIONAL SUPPORT FOR SCHOOL PROGRAMMES AND LEISURE TIME SURVEYS FOR THE PROTECTION OF ENVIRONMENTAL AND CULTURAL HERITAGE FROM HYDROGEOLOGICAL HAZARDS TECHNOLOGY FOR RAPID ARCHAEOLOGICAL SURVEY (MONUMENTS AND STRATIGRAPHIC EXCAVATIONS) UNDERWATER SURVEYS USING THE ACU-MAG SYSTEM VIRTUAL RECONSTRUCTION OF ENVIRONMENTS VOICES OF CAMPANIA PAST AND PRESENT: PERMANENT EXHIBITION OF MULTIMEDIA LANGUAGE ARCHIVES WIDE-ANGLE X-RAY SCATTERING (WAXS) DIFFRACTOMETER WEB GIS APPLICATIONS FOR DISPLAYING, MANAGING AND HANDLING GEOGRAPHIC DATA

Alcune domande per un soggetto (pubblico o privato) che opera nel settore della ricerca applicata ai Beni Culturali

• Qual è il miglior bilanciamento tra ricerca di base, R&D e servizi? • La capacità di offrire servizi diversificati ma integrati è un valore

aggiunto? • I servizi offerti devono necessariamente limitarsi ai settore dei BC? • La commistione tra autofinanziamento e finanziamento pubblico

droga il mercato? • Qual è il modo migliore per “contabilizzare” il lavoro del personale

universitario (pubblico se il soggetto è privato) • Integrazioni reciproche dei portafogli di soggetti diversi sono utili? • Sono da preferirsi sviluppi dell’offerta orientati dalla disponibilità

strumentale o dalla domanda (attuale o prevista)? • E’ utile affrontare il calvario burocratico della certificazione ISO ..?

Forensic! • Spinoff?

a) archaeometry by high-precision radiocarbon dating;

b) environmental science by 14C-based global carbon cycle studies;

c) nuclear astrophysics by the ERNA recoil mass separator;

d) nuclear safeguards and contrast to illegal nuclear fuel use by actinides AMS;

e) forensic applications of AMS;

f) tribology by 7Be implantation.

CIRCE - FIELDS OF ACTIVITY

14C AMS

26Al AMS 129I AMS

actinides AMS

7Be implantation

Nuclear Astrophysics

service

archaeology

climate change

tree rings.

mortars

Beam time sharing

• Accelerator order (Regional EU funds (POR)) 2003

• Accelerator installation and commissioning 2005

• People: a) Structured SUN 8 b) Structured external 6

c) PhD students, fellows, .. 15 d) Visiting scientists and fellows 10

• Papers on international journals ~ 50

• Annual income a) by service activity ~160 k€/yr b) Research projects (EU,INFN,SOGIN,PRIN) ~ 450 k€/yr

A few numbers about CIRCE

The AMS system CIRCE

Pelletron 3 MV – SNICS 40 samples Applications in archaeometry and environmental science

14C/12C bkg 510-16 s< 0.3% at 10-12 13C/12C s< 0.2%

Other isotopes: 10Be, 26Al, 129I, 236U, Pu

Le piccole quantità di materiale necessario per la datazione con

AMS rendono possibili:

Analisi virtualmente non distruttive di oggetti unici. Maggiore libertà di scelta del materiale da datare,

cui consegue la possibilità di una migliore correlazione con il contesto archeologico-ambientale

La possibilità di effettuare misure su più campioni (o frazioni) dello stesso materiale o date multiple su reperti in relazione temporale tra di essi.

Una chimica di decontaminazione più rigorosa.

Microcampioni. Sorgente gassosa ? Compound specific AMS? C

30000

35000

40000

45000

50000

55000

60000

0,00 0,50 1,00 1,50 2,00 2,50 3,00 3,50 4,00

mC(mg)

RC

age (

a)

H line

Z Line

20000

25000

30000

35000

40000

45000

50000

55000

60000

0,00 0,50 1,00 1,50 2,00 2,50 3,00 3,50 4,00 4,50 5,00 5,50 6,00

mC (mg)

RC

age (

a)

Average of Apparent age for m>0.5 mg: 0.17±0.04 pMC (52000±2900a)

Average of Apparent age for m>0.5 mg: 0.13±0.08 pMC (53000±4600a)

Risultati Blank Linea Zn- reduction

Risultati Blank Linea H-reduction 1) CO2 (g) + H2(g) CO(g) + H2O(g)

2) CO(g) + H2(g) C(s) + H2O(g)

-5000

-4500

-4000

-3500

-3000

-2500

-2000

0 20 40 60 80 100 120

RC

ag

e B

P

Agnano 3Paleoastroni 2

Agnano MS

Pomici Avellino

2° Protostorica1° Protostorica

Flegrea 1

Casalb

ore

Tau

rasi

Pia

no

di

So

rren

to

(Gau

do

)

Caiv

an

o

Sala

Co

nsil

ina

Gri

cig

nan

o(L

ate

rza)

Ate

na L

ucan

a

Palm

a C

am

pan

ia

San

Pao

lo B

els

ito

San

Pao

lo B

els

ito

Po

mic

i d

i A

vell

ino

Masseri

a R

ossa

San

Pao

lo B

els

ito

La S

tarz

a

San

Pao

lo B

els

ito

San

Pao

lo B

els

ito

P.l

e T

ecch

io

Po

gg

iom

ari

no

Eneolitico Antico Eneolitico Maturo Eneolitico Finale Bronzo Antico Inizio Bronzo Medio Bronzo Recente-Finale \Ferro

l’archeologo “in casa”

THE “AVELLINO PUMICES” SOMMA-VESUVIUS ERUPTION

#

SITE

Sample

RC age (y BP)

Ref. 1

Pomigliano

Paleosoil

3510±50

Alessio 1973

2

Pomigliano

Paleosoil

3610±50

“ 3

Cava dell’Arciprete

Paleosoil

3870±50

Alessio 1974

4

Palma Campania

Paleosoil

3760±70

Delibrias 1987 5

Sarno

Charred beam

3660±45

Marzocch. 1994

6

Sarno

Charred beam

3615±45

“ 7

Terzigno

Burnt veget.

3400±160

Albore-Liv. 1998

8

Somma Vesuviana

Charcoal

3520±160

“ 9

Ottaviano

Burnt veget

3480±100

“ 10

Frattaminore

Charcoal

3400±190

“ 11

Pratola Serra

Animal bone

3450±230

“ 12

Weight. Av. 7-11

3460±65

13

S. Paolo Belsito

Female skeleton

3560±110

Albore-Liv. 1997

Conv. RC ages

AMS

Eruzione delle "Pomici di Avellino"

Donna SPBS-

NA CapraCapra-

BochumTTT3-NA

3300

3400

3500

3600

3700

1997 1999 2001 2003 2005 2007 2009anno

RCage

Three radiocarbon datings in agreement among them: Three radiocarbon datings in agreement among them:

CIRCE codeCIRCE code Sample descriptionSample description PlacePlace Date (BP)Date (BP)

DSH 145DSH 145

Goat boneGoat bone Animal pen at Croce del Papa (Nola)Animal pen at Croce del Papa (Nola)

3558 3558 ±± 2020

DSH 103DSH 103 3560 3560 ±± 2020

DSH 146DSH 146 3533 3533 ±± 2222

3550 3550 ±± 20 yr BP20 yr BP

Atmospheric data from Reimer et al (2004);OxCal v3.10 Bronk Ramsey (2005); cub r:5 sd:12 prob usp[chron]

4200CalBP 4000CalBP 3800CalBP 3600CalBP

Calibrated date

3300BP

3400BP

3500BP

3600BP

3700BP

3800BP

Radio

carb

on d

ete

rmin

ati

on

3550±20BP

68.2% probability 1935BC (68.2%) 1880BC 95.4% probability 1960BC (77.9%) 1870BC 1850BC (10.9%) 1810BC 1800BC ( 6.6%) 1770BC

US 48_Agnano Montespina

eruption

US 45_Below Avellino

AVELLINO Pumices eruption

US 30_Above Avellino

AP1

US 150_Above AP1

AP2

US 85_Above AP2

DSH 153: 3513 ±20 BP (bone)

DSH 161: 3597 ±22 BP (bone)

DSH 105: 3361 ±20 BP ; DSH 160: 3368 ±47 BP; DSH 159: 3399 ±37 BP (bones)

DSH 154: 3380 ±23 BP (bone)

S.PAOLO BELSITO: a clear stratigraphic sequence of human frequentation since the

pre-Avellino eruption until the 2nd protohistoric eruption.

S.PAOLO BELSITO: a clear stratigraphic sequence of human frequentation since the

pre-Avellino eruption until the 2nd protohistoric eruption. At m ospher i c dat a f rom Rei m er et al ( 2004) ; O xCal v3. 10 Bronk Ram sey ( 2005) ; cub r : 5 sd: 12 prob usp[ chron]

2600CalBC 2400CalBC 2200CalBC 2000CalBC 1800CalBC 1600CalBC 1400CalBC 1200CalBC

Calibrated date

Stratigraphic sequence at S.Paolo Belsito (SPBS)

DSH154_SPBS 3380±23BP

DSH105_SPBS 3361±20BP

DSH160_SPBS 3368±47BP

DSH159_SPBS 3399±37BP

DSH153_SPBS 3513±20BP

GOAT_NOLA 3550±20BP

DSH161_SPBS 3597±22BP

Radiocarbon datings from Radiocarbon datings from samples collected in samples collected in

several sites with clear several sites with clear associations of settlements associations of settlements

below and above the below and above the volcanic products of the volcanic products of the Avellino and of the first Avellino and of the first

two protohistoric two protohistoric eruptions. eruptions.

Atmospheric data from Reimer et al (2004);OxCal v3.10 Bronk Ramsey (2005); cub r:5 sd:12 prob usp[chron]

3000CalBC 2500CalBC 2000CalBC 1500CalBC

Calibrated date

Below eruption - Above the 2° protohistoric

DSH138_PC 3666±52BP

DSH161_SPBS 3597±22BP

GOAT_NOLA 3550±20BP

DSH153_SPBS 3513±20BP

DSH143_MR 3492±23BP

DSH142_SPBS 3465±19BP

DSH156_SPBS 3426±48BP

DSH76_LaStarza 3466±20BP

DSH77_LaStarza 3423±25BP

DSH78_LaStarza 3470±24BP

DSH105_SPBS 3361±20BP

DSH160_SPBS 3368±47BP

DSH159_SPBS 3399±37BP

DSH53_P.le Tecchio 3368±19BP

DSH154_SPBS 3380±23BP

Charcoal

Animal Bone

Animal Bone

Human skull

Charcoal

Animal Bone

Charcoal

Charcoal

Charcoal

Animal Bone

Animal Bone

Animal Bone

Charcoal

Animal Bone

BELOW eruption

AVELLINO eruption

ABOVE eruption

ABOVE 1°

Protohistoric

ABOVE 2° Protohistori

c

AllAll thesethese datesdates provideprovide aa furtherfurther constraintconstraint (upper(upper andand lower)lower) toto thethe AvellinoAvellino eruptioneruption..

Servizi integrati Il ritratto di Acerenza

radiografia

XRF determinazione della specie

Riflettografia infrarossa

Datazione del supporto

100

200

300

400

500

600

700

800

900

1000

1100

1300 1400 1500

RC

age

BP

calendar age AD

sequence_rings average ring # RC age error AD year last ring AD year

average ring

Model

RC age dev c

2

ISCR 1-3 -2 514 38 1410 1407 553.2 -1.0 2.207

ISCR 14-16 -15 607 31 1402-1420 1394 587.2 0.6

ISCR 30-32 -31 624 33 conf. Interv. 68% 1378 648.8 -0.7

ISCR 43-45 -44 619 33 1365 633.0 -0.4

Wiggle matching

S. Maria Nova

sequence_rings average ring # RC age error AD year ring #1 AD year

average ring

Model

RC age dev2 c

2

PUNTONE_1_3 2 883 24 1159 1160 891.0 0.1 0.9

PUNTONE_16_18 17 882 24 1154-1177 1175 869.0 0.3

PUNTONE_29_31 30 874 18 conf. Interv. 68% 1188 860.6 0.5

ARCARECCIO_14_20 17 647 26 1342 1358 618.0 1.3 4.4

ARCARECCIO_50_57 53.5 577 22 1338-1348 1395 583.0 0.1

ARCARECCIO_88_94 91 551 39 conf. Interv. 68% 1432 484.0 3.0

CATENA8_10_12 11 982 21 1015 1025 986.0 0.0 0.3

CATENA8_30_32 31 953 29 1011-1020 1045 939.0 0.2

CATENA8_38_40 39 925 32 conf. Interv. 68% 1053 918.4 0.0

CATENA2_2-4 3 200 39 1653 1655 238.7 1.0 1.0

CATENA2_15-17 16 200 48 1648-1666 1668 192.4 0.0

CATENA2_28-30 29 163 35 conf. Interv. 68% 1681 161.3 0.0

MORALETTO_2-6 4 584 24 1403 1406 556.4 1.3 4.4

MORALETTO_37-41 39 431 26 1399-1408 1441 454.6 0.8

MORALETTO_72-76 74 316 38 conf. Interv. 68% 1476 373.6 2.3

100

200

300

400

500

600

700

800

900

1000

1100

1000 1100 1200 1300 1400 1500 1600

RC

age

BP

calendar age AD

intcal09

CATENA2

PUNTONE

ARCARECCIO

CATENA8

MORALETTO

Wiggle matching

Bone dating

• Mortars represent a class of building and art materials that are widespread at archeological sites from the Neolithic period on. They are virtually ubiquitous at archeological excavations since 7000 B.C. • Chronology of archaeological sites, mostly based on the dating of organic materials, may be affected by significant gaps between 14C dates and the real age of the site. • Comparison of mortar dates with organic samples may help in establishing the relationship between the archaeological context and the dated samples.

Factors influencing the success of mortars radiocarbon dating:

1. limestone must be completely dead-burnt before use,

otherwise dead C (primary) carbonate from bedrock will

falsify the date;

2. calcareous sand and aggregates may contain C of different

age with respect to mortar production time;

3. carbonatation must take place in a short time lag

4. running water containing dissolved CO2 can cause a

supplementary deposit on the mortar or an exchange in

carbonate ions.

VIRI Sample A

107

109

111

0 10 20 30 40 50 60 70lab #

pM

C(%

) VIRI Sample B

2600

2800

3000

0 10 20 30 40 50 60 70lab #

Rc

ag

e(a

)

VIRI Sample C

108

110

112

0 10 20 30 40 50 60 70lab #

pM

C(%

)

VIRI Sample D

2600

2800

3000

0 10 20 30 40 50 60 70lab #

Rc

ag

e(a

)

VIRI Sample E

33000

39000

45000

0 10 20 30 40 50 60 70lab #

Rc

ag

e(a

) VIRI Sample F

2300

2500

2700

0 10 20 30 40 50 60 70lab #

Rc

ag

e(a

)

VIRI Sample G

800

900

1000

1100

1200

1300

1400

0 10 20 30 40 50 60 70lab #

Rc

ag

e(a

) VIRI Sample I

7800

8300

8800

0 10 20 30 40 50 60 70lab #

Rc

ag

e(a

)

V

INTERCOMPARISON on

RADIOCARBON ANALYSIS

Certificazione di qualità

Sample A

n = 65

-2

-1

0

1

2

0.0 0.2 0.4 0.6 0.8 1.0s

D(p

MC

)

+1s

+2s

-1s

-2s

Sample B

n = 57

-150

-100

-50

0

50

100

150

0 10 20 30 40 50 60 70 80s

D(R

Ca

ge)

+1s

+2s

-1s

-2s

Sample C

n = 64

-2

-1

0

1

2

0.0 0.2 0.4 0.6 0.8 1.0s

D(p

MC)

Sample D

n = 58

-150

-100

-50

0

50

100

150

0 10 20 30 40 50 60 70s

D(R

Ca

ge)

+1s

+2s

-1s

-2s

Sample E

n = 30

-7000

-5000

-3000

-1000

1000

3000

5000

0 500 1000 1500 2000 2500 3000 3500 4000s

D(R

Cag

e)

+1

s

+2

-1s

-2s

Sample F

n = 38

-200

-100

0

100

200

0 20 40 60 80 100s

D(R

Ca

ge)

+1s

+2s

-1s

-2s

Sample G

n = 36

-200

0

200

0 50 100s

D(R

Cag

e)

+1

s

+2s

-1s

-2s

Sample I

n = 41

-200

-100

0

100

200

0 20 40 60 80 100s

D(R

Ca

ge)

+1s

+2s

-1s

-2s

z

SCORES vs

quoted

uncertainties

3° molar Mandible

Tibia

Humerus

Ulna

Femur

100

110

120

130

140

1975 1980 1985 1990 1995 2000 2005 2010 2015

pM

C (

%)

anno

TIPO_OFFSET ETICHETTE EDIZIONI FOTOCOPIE EDIZIONI_BIOPRIM MONTBLANC OFFSET2001 PALATINA AMALFI VELLUX_VLC COPY2 COPYB10

Datazione della carta (con la polizia scientifica)

1980

1990

2000

2010

1980 1985 1990 1995 2000 2005 2010 2015

raw

nominale

---- 6±2 ---- 12±2 ---- 18±2

CONCLUSIONI

The cesium sputter ion source is a 40-sample MCSNICS normally biased at -43 kV. Typical output from a F=1 mm sample pressed in Al cathodes for 12C- ions is 30 mA at 6 kV probe voltage and a total injection energy of 67 kV

A spherical electrostatic anal-yzer (r = 30 cm, plates gap = 5 cm) cuts the sputter energy tail of the beam, with a bending angle of ± 45°. The ESA can be rotated in view of the installation of a second ion source

The 90° double focusing L.E. magnet (r = .457 m, gap = 38 mm, ME/Z2 = 15) allows high resolution mass analysis for all stable isotopes in the periodic table. The insulated stainless steel chamber can be biased up to -15 kV for beam sequencing.

Typical injection times for 14C AMS are 350 ms for mass 12, 850 ms for m=13, and 100 ms for m=14.12C and 13C currents in the LE side Faraday cup are integrated for .1 ms and 8 ms, respectively.

The NEC 9SDH-2 Pelletron accelerator is housed in a lead-shielded steel tank filled with SF6 at ~85 psig. Two Pelletron chains are used in the charging system; about 100 mA are delivered to the terminal for operation at 3 MV.

For 14C AMS the accelerator is operated at 2.55 MV; typical ripple, as measured by a capacitive pick off, is .7 kV peak-to-peak. Stabilization is achieved by GVM feedback on the charging system PS; the long term stability, over about 24 hours needed for a batch of 40 samples, is better than 1 kV. In the stripper Ar is recirculated by two turbo-pumps; the working pressure is 10 m. The first tank opening was needed after 18 months of operation.

The double focusing 90° HE bending magnet has r=1.27 m, ME/Z2=176 and M/DM = 725, so that, e.g., 236U5+ at 3 MV can be analyzed with a beam spot size of 3.5 mm. For 14C AMS, 12C and 13C charges are measured via two off-set Faraday cups and high-precision current integrators, typically for .25 and 8 ms per cycle.

The two 45° electrostatic spherical analyzers (r= 2.54m and gap=3 cm) are operated at ± 40 kV; energy resolution is E/DE = 700. The isotopic contamination is suppressed so that virtually 0 counts are observed out of the 14C ROI

The four-anode ionization chamber, filled with isobutane at p=50 Torr, as well as most of the set up and control of the entire system is handled by the AccelNet computer based system via CAMAC interfaces or Ethernet.