Periodic Reporting for period 1 - LISA (Laser Ionization and Spectroscopy of Actinide elements)
Période du rapport: 2019-11-01 au 2021-10-31
The LISA consortium conducts research to increase our understanding of the atomic and nuclear properties of the actinides. These are a group of radioactive elements crucial to our basic understanding of nuclear chemistry and applications including nuclear power. Of long-standing interest to the fields of fundamental atomic and nuclear physics, their study is an essential prerequisite for understanding the superheavy elements.
Due to their chemical similarities, complex atomic structure and hugely varying scarcity, the production and isolation or extraction of the actinides for study or exploitation requires a range of complementary and often sophisticated approaches.
The research objectives of LISA are:
Laser-based actinide ion beam production and purification techniques;
Laser technology for laser spectroscopy;
Measurement of ionization potentials and electron affinities (an insight into chemical behaviour);
Atomic and nuclear properties from laser spectroscopy studies;
Applications: theranostic/medical applications and environmental monitoring.
Due to their chemical similarities, complex atomic structure and hugely varying scarcity, the production and isolation or extraction of the actinides for study or exploitation requires a range of complementary and often sophisticated approaches.
The research objectives of LISA are:
Laser-based actinide ion beam production and purification techniques;
Laser technology for laser spectroscopy;
Measurement of ionization potentials and electron affinities (an insight into chemical behaviour);
Atomic and nuclear properties from laser spectroscopy studies;
Applications: theranostic/medical applications and environmental monitoring.
All LISA ESRs are enrolled in PhD programs.
Training events:
Training Kick-Off: Organized by KUL on 24-25 Nov 2020, online.
LISA MidTerm meeting (25-26 Nov, online).
The two events were combined and included: introduction by WP leaders, 3-min thesis presentations by the ESRs, innovation & entrepreneurship, communication strategy, team building trivia night.
General Training 1: Organized by IREPA on 7-10 Dec (M14) (online): societal impact, laser technology and actinide introduction, laser safety (IREPA Laser), and presentation skills. Affiliates introduced themselves in a 3-min thesis format.
Specialised training events:
ST 3: Organized by JGU (Mainz, Germany) https://indico.cern.ch/event/1025015/ in Mainz, Germany. Hybrid event (50% live, 50% online) with hands-on laser and radiochemistry lab work.
ST 2: ‘Advanced techniques for the production and study of the actinides’ https://indico.cern.ch/event/1068874/ in Jyvaskyla, Finland. The first live training event (all of the ESRs present).
Results:
New Actinide beams at CERN/ISOLDE: The first RILIS-ionized beams of Pu and Np!
ESR 3 - CERN led the first dedicated study of actinide release from irradiated ISOLDE targets, combined with the Resonance Ionization Laser Ion Source (RILIS) for selective ionization of the actinide elements, and state-of-the art single-ion detection methods. This was a multi-ESR collaborative effort! Laser ionization data for U, Pu, Ac, Np was provided by ESR 5 - JGU, as part of a compilation that she has submitted as a LISA report. The RILIS preparation was performed by ESR 2 - CERN and ESR 9 - M-Squared. The results were presented in the ISOLDE workshop in Dec 2021 by ESR 3 (https://indico.cern.ch/event/1073670 - 'best young speaker' prize!).
A new high-resolution laser spectroscopy device for ISOLDE: Key progress has been made on the perpendicularly-illuminated LIST ion source at ISOLDE.
A specially modified ion beam extraction electrode was commissioned. This enables ion beam extraction while allowing for laser access to a set of mirrors next to the ion source cavity for perpendicular illumination of the emerging atom cloud. The complete PI-LIST test and commissioning is scheduled for Q1 of 2022.
Complementary to ISOLDE, the thin-target gas-cell isotope factory at Jyvaskyla has access to heavier actinides than are available at ISOLDE. ESR 4 has performed yield measurements of actinide isotopes produced in Jyvaskyla: presented at the Mainz University actinide workshop on 26-28 May 2021. ESR 4 had also his proposal to perform further yield measurements of long lived actinides accepted at the JYFL PAC in April 2021.
Investigating low energy nuclear isomers is a hot topic at the moment, with recent prolific search and study of lowest energy isomer known: Thorium 229m (~8eV).
ESR 4 and ESR 5 (seconded to JYFL) are targeting the second lowest-lying isomer known: the ~76 eV isomer 235mU and have determined the most suitable atomic transition spectroscopy of this isomer. Secondly, ESR 11 - JGU and ESR 4 (on secondment in JGU) have studied methods for optimised U 235m isomer production in the JYFL gas cell. Thirdly, ESR 11 made 19 Pu-239 sources by molecular plating, and three Pu-240 sources to act as calibration sources for the 235mU project of ESR 4. ESR 11 joined ESR 10 - GSI (also on secondment) in JYFL and characterised these sources using the Rutherford back scattering (RBS) method and decay spectroscopy.
At GSI, where the very heaviest of the Actinides are produced, ESR 10 has been optimising the RADRIS setup for the study of No and Lr:
- New Yt ionization schemes were found.
-The optimal filament for evaporation of lawrencium was found to be Hafnium.
- A new movable detector setup was tested (75% efficiency improvement).
New facilities:
In GANIL ESR 8 has made a test bench for entrance window leak tests for the future S3 gas cell and determined that the Titanium windows of 5 μm, which are suitable for Day-1 experiments at S3 work within the required specification.
New equipment:
ESR 9 and ESR 15 visited CERN and Jyvaskyla to understand the laser requirements for LISA. ESR9 held an international tunable laser technology mini workshop to begin brainstorming on the laser technology needs for the community.
Atomic spectroscopy:
ESR 6 has measured the electron affinity (EA) of cesium to be 0.471 621 1(19) eV (paper being prepared). She tested and delivered a larger neutral particle detector to CERN where she is on secondment. She has an approved letter of intent for a Po- experiment at ISOLDE.
ESR 5 identified a new ionisation scheme for Neptunium, for increased ionization efficiency.
Theoretical input:
For the Po EA project of ESR 06, ESR 14 carried out Dirac-Coulomb CCSD(T) calculations of the electron affinities of both Po and Te, assisting the ESR 6 project.
Practical applications:
ESR 1 performed release/deposition simulations of exotic gold isotopes produced at CERN ISOLDE (reported in Physical Review C 104, 024326 (2021). An ionization efficiency of 10% was reached and 95% recovery of 225 Ac from collection foils achieved for 225Ac at CERN MEDICIS.
In Hannover, ESR 12 is working with ESR 11 to produce mixed-actinide samples by the novel drop-on-demand pico-litre printing system of JGU Mainz to assist with analysis of environmental samples using the rL-SNMS method being further developed within LISA.
Training events:
Training Kick-Off: Organized by KUL on 24-25 Nov 2020, online.
LISA MidTerm meeting (25-26 Nov, online).
The two events were combined and included: introduction by WP leaders, 3-min thesis presentations by the ESRs, innovation & entrepreneurship, communication strategy, team building trivia night.
General Training 1: Organized by IREPA on 7-10 Dec (M14) (online): societal impact, laser technology and actinide introduction, laser safety (IREPA Laser), and presentation skills. Affiliates introduced themselves in a 3-min thesis format.
Specialised training events:
ST 3: Organized by JGU (Mainz, Germany) https://indico.cern.ch/event/1025015/ in Mainz, Germany. Hybrid event (50% live, 50% online) with hands-on laser and radiochemistry lab work.
ST 2: ‘Advanced techniques for the production and study of the actinides’ https://indico.cern.ch/event/1068874/ in Jyvaskyla, Finland. The first live training event (all of the ESRs present).
Results:
New Actinide beams at CERN/ISOLDE: The first RILIS-ionized beams of Pu and Np!
ESR 3 - CERN led the first dedicated study of actinide release from irradiated ISOLDE targets, combined with the Resonance Ionization Laser Ion Source (RILIS) for selective ionization of the actinide elements, and state-of-the art single-ion detection methods. This was a multi-ESR collaborative effort! Laser ionization data for U, Pu, Ac, Np was provided by ESR 5 - JGU, as part of a compilation that she has submitted as a LISA report. The RILIS preparation was performed by ESR 2 - CERN and ESR 9 - M-Squared. The results were presented in the ISOLDE workshop in Dec 2021 by ESR 3 (https://indico.cern.ch/event/1073670 - 'best young speaker' prize!).
A new high-resolution laser spectroscopy device for ISOLDE: Key progress has been made on the perpendicularly-illuminated LIST ion source at ISOLDE.
A specially modified ion beam extraction electrode was commissioned. This enables ion beam extraction while allowing for laser access to a set of mirrors next to the ion source cavity for perpendicular illumination of the emerging atom cloud. The complete PI-LIST test and commissioning is scheduled for Q1 of 2022.
Complementary to ISOLDE, the thin-target gas-cell isotope factory at Jyvaskyla has access to heavier actinides than are available at ISOLDE. ESR 4 has performed yield measurements of actinide isotopes produced in Jyvaskyla: presented at the Mainz University actinide workshop on 26-28 May 2021. ESR 4 had also his proposal to perform further yield measurements of long lived actinides accepted at the JYFL PAC in April 2021.
Investigating low energy nuclear isomers is a hot topic at the moment, with recent prolific search and study of lowest energy isomer known: Thorium 229m (~8eV).
ESR 4 and ESR 5 (seconded to JYFL) are targeting the second lowest-lying isomer known: the ~76 eV isomer 235mU and have determined the most suitable atomic transition spectroscopy of this isomer. Secondly, ESR 11 - JGU and ESR 4 (on secondment in JGU) have studied methods for optimised U 235m isomer production in the JYFL gas cell. Thirdly, ESR 11 made 19 Pu-239 sources by molecular plating, and three Pu-240 sources to act as calibration sources for the 235mU project of ESR 4. ESR 11 joined ESR 10 - GSI (also on secondment) in JYFL and characterised these sources using the Rutherford back scattering (RBS) method and decay spectroscopy.
At GSI, where the very heaviest of the Actinides are produced, ESR 10 has been optimising the RADRIS setup for the study of No and Lr:
- New Yt ionization schemes were found.
-The optimal filament for evaporation of lawrencium was found to be Hafnium.
- A new movable detector setup was tested (75% efficiency improvement).
New facilities:
In GANIL ESR 8 has made a test bench for entrance window leak tests for the future S3 gas cell and determined that the Titanium windows of 5 μm, which are suitable for Day-1 experiments at S3 work within the required specification.
New equipment:
ESR 9 and ESR 15 visited CERN and Jyvaskyla to understand the laser requirements for LISA. ESR9 held an international tunable laser technology mini workshop to begin brainstorming on the laser technology needs for the community.
Atomic spectroscopy:
ESR 6 has measured the electron affinity (EA) of cesium to be 0.471 621 1(19) eV (paper being prepared). She tested and delivered a larger neutral particle detector to CERN where she is on secondment. She has an approved letter of intent for a Po- experiment at ISOLDE.
ESR 5 identified a new ionisation scheme for Neptunium, for increased ionization efficiency.
Theoretical input:
For the Po EA project of ESR 06, ESR 14 carried out Dirac-Coulomb CCSD(T) calculations of the electron affinities of both Po and Te, assisting the ESR 6 project.
Practical applications:
ESR 1 performed release/deposition simulations of exotic gold isotopes produced at CERN ISOLDE (reported in Physical Review C 104, 024326 (2021). An ionization efficiency of 10% was reached and 95% recovery of 225 Ac from collection foils achieved for 225Ac at CERN MEDICIS.
In Hannover, ESR 12 is working with ESR 11 to produce mixed-actinide samples by the novel drop-on-demand pico-litre printing system of JGU Mainz to assist with analysis of environmental samples using the rL-SNMS method being further developed within LISA.
-First RILIS ionised beams of Pu and Np at ISOLDE.
-Installation of a PI-LIST compatible extraction electrode at ISOLDE.
-Accepted proposal on the study of Ac isotopes with PI-LIST with the first on-line experiment expected in 2022.
-New 2-step ionization schemes are documented for U, Pu, Ac, Np. Further scheme development is ongoing.
-Yield measurements and mass spectrometry of actinide isotopes produced by the 232Th(p,x)Y reaction in Jyvaskyla.
-Optimised Pu targets for the study of 235U 76 eV isomer at Jyvaskyla.
-New ionization schemes for Yt at GSI.
-Hf determined to be an optimum filament for Lr spectroscopy.
-A new RADRIS detector with a 75 % efficiency improvement.
-Vacuum tests of 5um Ti windows for S3-GANIL.
-Electron affinity of Cs measured.
-New Gothenburg-built detector for EA measurements delivered to ISOLDE.
-10% ionization efficiency and 95% recovery of the collected 225 Ac ay CERN-MEDICIS.
-Installation of a PI-LIST compatible extraction electrode at ISOLDE.
-Accepted proposal on the study of Ac isotopes with PI-LIST with the first on-line experiment expected in 2022.
-New 2-step ionization schemes are documented for U, Pu, Ac, Np. Further scheme development is ongoing.
-Yield measurements and mass spectrometry of actinide isotopes produced by the 232Th(p,x)Y reaction in Jyvaskyla.
-Optimised Pu targets for the study of 235U 76 eV isomer at Jyvaskyla.
-New ionization schemes for Yt at GSI.
-Hf determined to be an optimum filament for Lr spectroscopy.
-A new RADRIS detector with a 75 % efficiency improvement.
-Vacuum tests of 5um Ti windows for S3-GANIL.
-Electron affinity of Cs measured.
-New Gothenburg-built detector for EA measurements delivered to ISOLDE.
-10% ionization efficiency and 95% recovery of the collected 225 Ac ay CERN-MEDICIS.