esr3 wp2 d2 - indico · volume chromatography gas 1 gas 2 solid samples (mass markers) concept for...

ESR3 – WP2 – D2.4

Target developments for extraction of actinides from thick ISOL targets followed by laser-induced molecular break-up and/or ionization.

ESR3 – WP2 – D2.4

S.Rothe | LISA Kickoff CERN | ESR3 - Molecular Actinide Beams 2

ESR3 – WP2 – D2.4

Objectives:

• Study and optimize the reaction conditions required to create volatile molecular species of refractory elements in general and actinides in particular.

• Develop a dissociation scheme for the provision of atomic species suitable for efficient laser ionization or in-source laser spectroscopy.

Expected results:

• Extraction of radiogenic actinide elements from an ISOL target and delivered in atomic form to the users. Determine the production yield and purity of the beams and report the new beam availability to the community.

Planned secondment(s):

• JGU (Christoph E. Düllmann) – M8-10 – working on the sample preparation to be used for the actinide molecular release studies;

• TRIUMF (Thomas Day Goodacre, Peter Kunz) – M15-17 – Extraction of actinides from thick targets at the ISAC facility. Participation in activities around radioactive ion beam development involving actinide beams and molecular beam extraction. Gaining experience in radioactive detection techniques used to assess the quantity and quality of the produced isotopes.

Enrolment in Doctoral degree:

• JGU in the Department of Chemistry under the supervision of Prof Christoph E. Düllmann


Outline

• Motivation for molecular beams

• Optimization of reaction conditions

• Develop a dissociation / ionization scheme

• Determine production yield


ISOLDE: Isotope Separation On Line

𝐵𝑒𝑎𝑚 𝐼𝑛𝑡𝑒𝑛𝑠𝑖𝑡𝑦 = 𝜎. 𝑗. 𝛮𝑡. 𝜀

𝜀 = 𝜺𝒅𝒊𝒇𝒇𝜺𝒆𝒇𝒇𝜺𝒊𝒔𝜺𝒔𝒆𝒑𝜺𝒕𝒓𝒂𝒏𝒔

𝑁𝑡 – Nr of exposed atoms [dim]

𝑗 – Proton flux [cm-2]

𝜎 – Cross section [mb]

𝜀 – Efficiency [%]

Extraction opticsMass separator

Target unit

1.4GeV Protons

4. Ionization

3. Effusion

2. Diffusion

1. Production

5. Mass Separation

6. Transport

(pulsed)

Protons

+/- 8V500 A

+/- 9 V1000 A

Ion

Source

Proton

Transfer

line

Extraction

electrode

up to 2300 °C20 cm

Target heating (1 – 2kW), <~10% beam power

Adapted from


boiling/melting points vs. ISOLDE Yields

actinides

TiB Mo

La

W Th

https://www.periodic-table.org/wp-content/uploads/2019/07/melting-and-boiling-point-chemical-elements-chart-min.png


Target materials operated at < 2200 C

Si

https://www.periodic-table.org/wp-content/uploads/2019/07/melting-and-boiling-point-chemical-elements-chart-min.png


Molecular Beams – Why?

• Beam purification

• Shift the mass region to a higher mass to avoid

isobaric contaminants. e.g. GeS, SnS, SeCO, LnO

• Beam extraction by In-situ volatilization

• Elements with very low volatility are not released

• Reactive elements can be chemically trapped

Target material

SeCO

8B 8BF3

SF6 (g)

Boron

Low Volatility (m.p. 2076 °C)

reactive with many metals

Boron trifluoride

gaseous even at RT

very stable

HSC simulation

Jochen Ballof | ISOLDE Workshop | 5.DEC.2017

Optimize reaction conditions

• target material

• U vs. Th

• Metal vs. Carbide vs. Oxide

• target microstructure

• Investigate nano materials , stabilize nanostructure

• Reactive gas

• (O, F, S, …)

• Reaction conditions

• Concentrations, temperatures


Thorium vs Uranium


! Release properties to be studied

! Simulated results require validation

• ThC is a standard target material at ISOLDE

• Nano ThC possible with new nano lab

• co-development with SCK*CEN possibleFLUKA Simulations: : Joao Pedro Ramos

In-target production

Nanomaterials

TiC+CB – J.P. Ramos, et al.

No

v-

20

14

No

v-

20

14

LaC2 + 2C – J. Guillot, et al.

No

v -

20

14

UC2 + 2C – A. Gottberg, et al.

Ap

r-2

01

5

MWCNT – C. Seiffert, et al.

SiC - S. Fernandes, et al.

20

10

*submicron

*1st

nanomaterial

at ISOLDE

2011

CaO – J.P. Ramos, et al.

João Pedro Ramos | 07/09/2017

MEDICIS-Promed Specialized Training on Radioisotope

Production

Adopted from

Study effects of reactive gas to actinide nano materials

S.Rothe | LISA Kickoff CERN | ESR3 - Molecular Actinide Beams

11

Molecular Beams – The classical approach

U. Köster et al.

NIMB 266 (2008), 4229

EPJ-ST (2007), 285

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

1 2

H He

3 4 Halides Al-X Sulfides 5 6 7 8 9 10

Li Be B C N O F Ne

11 12 X-CO Oxides 13 14 15 16 17 18

Na Mg Al Si P S Cl Ar

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

55 56 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86

Cs Ba La... Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

87 88 71 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118

Fr Ra Ac... Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og

Selected molecular sidebands

Formation of molecules under low pressure conditions and high temperatures

S.Rothe | LISA Kickoff CERN | ESR3 - Molecular Actinide Beams

What are the best sidebands for actinide release ?

1st experiments planned with irradiated targets at MEDICIS

Slide adapted from: Jochen Ballof | ISOLDE Workshop | 5.DEC.2017

Beyond Uranium


UCx , 1.4GeV, Fluka

Neptunium

NpF6

BP: 55C239Pu: 1E7 /s

Plutonium

Study NpF6 release

Pump stand (YPS1)


Offline 1 (YOL1)


Offline 2 (YOL2)

https://home.cern/news/news/experiments/isoldes-new-offline-2-source-nears-completion

Frontend, Separator magnet

RFQ-CB


https://home.cern/news/news/experiments/isoldes-new-offline-2-source-nears-completion

16

VADIS sourceHeated reaction

volume Chromatography

Gas 1

Gas 2

Solid Samples

(mass markers)

Concept for a dedicated development unit for molecular beams

RGA

MagnetFaraday

CupFaraday

CupScanner

Study chemical reactions

- Injection of gases and vapor of solid

samples into reaction volume

- Suppression by quartz and other materials

Parameters

- 2 gases, controllable flow rates

- 2 mass markers

- Controllable temperatures in reaction volume

and chromatography column

- Materials for chromatography and

- Materials in reaction volume (target matrix)

- better understanding of molecule formation

- improve reliability of existing beams, tailor new beams

Studying molecular beam formation

J.BallofS.Rothe | LISA Kickoff CERN | ESR3 - Molecular Actinide Beams 16

17



Gas 1

Gas 2

Solid Samples

(mass markers)


RGA

MagnetFaraday

CupFaraday

CupScanner


• Move residual gas analyzer to identify

separated beam composition through

molecular break up patterns

JochenS.Rothe | LISA Kickoff CERN | ESR3 - Molecular Actinide Beams 17

18



Gas 1

Gas 2

Solid Samples

(mass markers)


MagnetFaraday

CupFaraday

CupScanner


• Add Multi Reflection Time of Flight (MR-ToF)

mass spectrometer: allows ISOBAR separation.

• Collaboration with MIRACLS experiment launched

RGA

Cu

rte

sy: S

.Ma

lbru

no

t

Example TOF spectrum on mass 46

Ti

Sc

KCa

J.BallofS.Rothe | LISA Kickoff CERN | ESR3 - Molecular Actinide Beams 18

First prototype for reaction chamber tested at YOL1

BaO + CF4 -> BaF2 + x -> BaF+

1 reacting gas

1 sample supply

Surface ionization

Leak valve

Reaction chamber

Externally heated

V.Samothrakis, M.Ballan, J.Ballof, D.Leimbach, B.Crepieux, S.Rothe et al.

Ion source

Gas supply

Multiple gasses

Plasma sources, Negative ions

3 gas lines to

new Frontends


Photocathode source

VADIS source at ambient temperatureElectron generation by laser, not thermal evaporation

Motivation- Ionization of fragile molecules- No decomposition on hot surfaces- Diagnostic tool to measure ionization properties

Laser properties

(PHARROS)

Pulse length 265 fs

Power 4.5 W

Wavelength 343 nm

Rep. Rate 50 kHz

First Results: Mass spectrum of Mo(CO)6 + Kr

Two operation modes found

Photo cathode Direct laser breakup

Anode biased Anode off

Magnet 6A Magnet off

Krypton ionized Krypton not ionized

Mo(CO)3 predominant Mo(CO)5 predominant

Set up

J. Ballof, D. Leimbach, B.A. Marsh, A. Ringvall-Moberg, S. Rothe, T. Stora, S. Wilkins


THE ISOLDE Yield station (YYS)

Proposal: install spare YYS2 at GLM

• Used for beam development

• Can be used in p.sharing mode

with minimal impact to ISOLDE

physics

• Opportunistic development, in-

source laser spectroscopy

• Upgrade (LS3…): integrate

MR-ToF-MS


esr3 wp2 d2 - indico · volume chromatography gas 1 gas 2 solid samples (mass markers) concept for...

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