João Pedro RAMOS ISOLDE Workshop 2015 Radioactive beams at ISOLDE: Status and Developments João Pedro RAMOS (CERN/EPFL) On behalf of the ISOLDE Target and Ion Source Development Team EN-STI-RBS

João Pedro RAMOS ISOLDE Workshop The TISD Team Yisel Palenzuela Joao Pedro Ramos Tania Mendonça Jochen Ballof Thierry Stora Melanie Delonca Basil Gonsalves Target and Ion Source Development Team: Online target characterization - beam quality (aka Yield Checks) Target nanomaterial developments (João, Alex, Wonjoo)  CaO, UC x, LaC 2, TiC Ion source developments (Yisel)  VADIS New target concepts (Tânia and Melanie)  LIEBE Project Molecular beams (Jochen, Christoph)  Beams of refractory elements MEDICIS (Yisel and Basil)  Target design and beam optics Ex-TISDs For more about MEDICIS see T. Stora talk today at 10:10. New UC 2 targets Negative beams General report on 2015 yields and targets TRIUMF RILIS RISP

João Pedro RAMOS ISOLDE Workshop Refractory element beams – Metal Carbonyls 1 2 H He LiBeBCNOFNe NaMgAlSiPSClAr KCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKr RbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXe CsBaLa...HfTaWReOsIrPtAuHgTlPbBiPoAtRn Known Carbonyle compoun ds V(CO) 6 Cr(CO) 6 Mo(CO) 6 W(CO) 6 Tc 2 (CO) 10 Re 2 (CO) 10 Ru(CO) 5 Os(CO) 5 Co 2 (CO) 8 Rh 2 (CO) 8 Ir 4 (CO) 10 Ni(CO) 4 Mo CO (g) refractory volatile p beam Neutron converter 3 U Foils, 25 µm Mo Container, Filled with CO 105 Mo production yield: ~ 10 8 ions / uC (FLUKA) J. Ballof, et. al.

João Pedro RAMOS ISOLDE Workshop Test for shower feasibility done: Minimum droplets size is 0.4 mm diameter (diffusion) Design finalized Manufacturing started (photographs) Full target manufacturing and assembly planned for April 2016 The LIEBE project: toward short-lived isotopes M. Delonca, T.M. Mendonça, et. al. LIquid Eutectic Lead Bismuth Loop Target for Eurisol Improve exotic Hg beams by up to factor 10!

João Pedro RAMOS ISOLDE Workshop VADIS tests and developments Continuation of tests on the application of the RILIS inside VADIS *picture courtesy of T. Goodacre Ga Y. Palenzuela, RILIS, et. al. Development and characterization of VADIS ion source Understanding mode of operation for high efficiencies Measurement of efficiencies of some metals in VADIS ongoing VADIS + RILIS (Ga tests) VADIS Efficiency *preliminary results

João Pedro RAMOS ISOLDE Workshop Low Z target materials in 2015 Silicon Carbide sub-micron pressed powder 8B (as BF 2 ) See talk of C. Seiffert right after 10C as CO delivered for physics 3.0E+05 /μC Database – 7.0E+05 /μC 13N+13N contamination (strange?!?) Same intensity as the 10CO beam Normally a molecule is an isotope+stable atom CaO is a material full of surprises! Mg A Yield (μC -1 )Target °C Ta source at 1880°C Calcium Oxide nanometric powder To deliver n-deficient Mg beams Successful physics run Multiwalled Carbon Nanotubes Nanometric pressed powder Surprises not over yet! Next slide! Physics yields courtesy of IDS, and B. Blank #519 #513 Target conservative – margin for more!

João Pedro RAMOS ISOLDE Workshop Room Temperature Release from nano CaO spallation recoil momentum from the nat Ca(p,x) 35 Ar reaction Yields μC -1 High Temp. Room Temp. 31Ar (400°C) 1.3– Ar (800°C) 2.3E7 1.0E7 FLUKA Recoil energy of 35Ar 9.23±1.77 keV J.P Ramos, et. al, submitted to NIMB (EMIS 2015 Proceedings) 10 nm 35Ar + average range in CaO CaO particles are around 40 nm Only possible with volatile elements!

João Pedro RAMOS ISOLDE Workshop Negative beams Gadolinium Hexaboride - GdB6 (thermionic electron source) Electron deflector – prevent damage by electron acceleration to 30keV Neutralizer – Cesium atoms to neutralize the overall charge in the source. Results still in analysis! More tests in the offline separator in a near future! Two targets tested (over 2 weeks): Niobium foils Thorium Oxide F - Cl - Br - I - At - 0V  Floating Possible ion source surface poisoning (Cs mass marker compound) Material studies! Ion source temperature effect not clear. Significant electron deflector influence on the yields Huge effect of the Cs neutralizer Difficult to control (no current to measure – changes over time) In one test a small change in Cs oven ( Δ= 3A) – brought 20x 87Br Yields on 85Br close to the run on 2005! Offline effiencies measured for Br and I: 17% ThO 2 Target 2000°C (**1800°C) | Ion source at 1800°C  Not connected during most of the run!

João Pedro RAMOS ISOLDE Workshop Nanocomposite: titanium carbide-carbon 500nm Carbon Black + TiC selected! Higher release! Nanostructure stable up to 2000 o C Yields very high on Li and Na Not so much on K and Ca 2nd iteration summer student project Sylvain Badie Material with a ~6x higher surface area, more porous and stable up to 2100°C J.P Ramos, et. al. Stable yields Solid State Physics Diffusion Chamber Generaly Ti foils yields decrease fast

João Pedro RAMOS ISOLDE Workshop nanoLaC 2 – Re Online Tests The target material could be tested with and without fluorination by CF 4 injection at 2 different temperatures (1700 o C and 1900 o C) The material sublimates from 1900 o C, and the total beam intensity starts limiting the ion source efficiency Fast Fluorination (big surface area to interact) Isotopes of Li, Na, In, Cs, Ba could be assessed. The release of Cs is limited presumably by effusion at T<1900 o C (nano-UC x results) J. Guillot, A. Gottberg, J.P Ramos, W. Hwang, et. al. Standard LaC2 Nano LaC2

João Pedro RAMOS ISOLDE Workshop The New UO 2 batch Target at 1990 o C Ta source at 1780 o C (quartz cold line reduces intensity down to 1/2) Successful beam time for physics Target at 2050 o C Ta source at 2000 o C Protons on converter Towards the end Yield Checks IDS/ISOLTRAP Database μC -1 DB 30Mg2.3E66.0E5 30Al3.2E65.7E6 33Mg3.0E3 Small difference in a few impurities to old batch Not the nanoUCx Material characterization and comparison to old batch to be done. Physics yields courtesy of IDS and ISOLTRAP Target at o C Ta source at o C Material generally operated at conservative temperatures!! Margin for improvement! Protons on target No quartz #550 #547 & #548 #543

João Pedro RAMOS ISOLDE Workshop Target – 2150°C Ta source – 2100°C Open circles - isomers Gold beam time Narrow band Au yields #524 New UC batch, Yield tools– ISOLTRAP (MR-TOF), IDS, Windmill Polonium beam time - ISOLTRAP Target – 2000°C Ta source – 1960°C After target optimization x20! (and ISOLTRAP + 30%) Broad band No Blaze Narrow band Po yields Broad band Cu beam time ISOLTRAP Converter used Target 1950 o C Ta source at 1950 o C Stable for 3 weeks+ Protons on target #539 UC x target Old batch (stored) Target – 1950°C Ta source – 1950°C Underestimated Zn beam time HIE-ISOLDE #549 #539 New UC batch gives high yields at conservative temperatures! Users setups are powerful tools for Yield Checks and feedback (especially MR-TOF)! Promote more communication Users  TISD!

João Pedro RAMOS ISOLDE Workshop Nano Uranium Carbide Online at ISOLDE A. Gottberg, et al. ActILab Standard UC x *decrease does not happen so far for new U batch Important material  Took more than 80% of the protons of this year! Discussions already started to transform this material into an ISOLDE everyday material: Current production – 2 persons, 1 month  1 target (similar for almost all nanomaterials) Objective – 1 person, 1 week  1 target – FACTOR 8 X 100 more magnification

João Pedro RAMOS ISOLDE Workshop Thank You! Questions or comments? End Thanks to: Fellow TISD colleagues (info for this presentation) ISOLTRAP (yields provided) IDS Collaboration (yields provided) Windmill (yields provided) EN-STI-RBS colleagues

João Pedro RAMOS ISOLDE Workshop Possible problems (examples) – spare slide Ca A (s -1 ) E E >3.0E-01 Broken units during online period: #524-UC-Ta (used) #507-UC-W (used) #511-Pb-VD7 (used) All used targets 2x, 3x UC x + xO 2 → UO 2 + xCO 2 UO 2 + 4C → UC 2 + 2CO Spontaneous oxidation! Temperature However not fully reversible Irreversible changes to the microstructure! Two used VADIS units failed this year Anode photo after thermal cycle Metal surface is initially smooth Anode bends and touches other parts Short circuit Heat shields touching transfer line COLLAPS run Should be at least x10 Too high temperature! 400 nm SSA = 38 m 2 /g 48h at 800 o C SSA = 4 m 2 /g 48h at 1200 o C 3 μm In the frontend, heating #545