Download presentation
Presentation is loading. Please wait.
Published byEdwina Green Modified over 8 years ago
1
Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE João Pedro Ramos 11 th of March 2013 T. Stora, A. M. R. Senos, P. Bowen A. Gottberg, T. M. Mendonça, C. Seiffert
2
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Table of Contents 2/25 Introduction ISOLDE Beam production Target materials Nanostructured calcium oxide target Ti-based refractory target materials Uranium carbide target developments
3
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Introduction Basic concepts 4/25 Introduction
4
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE ISOLDE Facility at CERN 4/25 (Isotope Separator OnLine DEvice) 1000 Isotopes available Z=2 to 92 73 chemical elements 10 -1 to 10 11 ions/s 30 targets per year 300 to 400 8h shifts per year 30-40% of all CERN protons Beams up to several MeV/u Introduction
5
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE ISOLDE Facility at CERN CERN. CERN in a nutshell. http://public.web.cern.ch/public/en/about/About-en.html (accessed August 13, 2011).http://public.web.cern.ch/public/en/about/About-en.html 5/25 Introduction
6
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Container Transfer Line Ion Source ISOLDE Facility at CERN 6/25 Köster, U. Intense Radioactive-Ion Beams Produced with the ISOL Method. The European Physical Journal A 2002, 15, 255-263. Target unit pictures courtesy of Stefano Marzari. Introduction
7
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE RIB Production 7/25 Protons +/- 8V 500A +/- 9V 1000A 4. Ionization 3. Effusion 2. Diffusion 1. Production (Nuclear Reactions) Target Material – 5 - 200g/cm 2 “Oven” (Ta,Mo,Nb,C) Ion Source Transfer Line (Ta, Mo, SiO 2 ) * Introduction
8
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE RIB Production 8/25 Production Diffusion Effusion Ionization Nuclear reactions Thermalization Out of the material grains Through porosity Transfer line Proton flux Cross-section Nr. exposed atoms Ionization Surface Ionization Elements with low ionization potential Plasma Ionization Very efficient but not selective Laser Ionization Selective metallic elements ionization. Introduction Transfer lines Element Selection Condensation
9
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Oxides, carbides, metals or molten salts Powders, pellets or liquid form Material characteristics High production cross section Stability at high temperatures Resistance to radiation damage Microstructural characteristics: Nanometric grain size High porosity (>30%) Macroporosity (>100nm) Target Materials 9/25 Improved effusion and mainly diffusion of alkali, alkali-earth and noble gases Diffusion usually limits the release Fernandes, S. Submicro- and Nanostructured Porous Materials for Productin of High-Intensity Exotic Radioactive Ion Beams; PhD Thesis; École Polytechnique Fédérale de Lausanne: Lausanne, 2011. Uranium carbide pictures courtesy of Alexander Gottberg Nanometric CaO powder target Al 2 O 3 - SEM Introduction
10
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Nanostructured CaO Master thesis subject CERN – T. Stora University of Aveiro – A.M.R. Senos 10/25 CaO
11
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Motivation Main issues: Unstable yields Low since the beginning Drop over time Turrion, M.; Urszula, H.-I. ISOLDE Yield Database. https://oraweb.cern.ch/pls/isolde/query_tgt (accessed December 1st, 2011)https://oraweb.cern.ch/pls/isolde/query_tgt Shift numbers by courtesy of Magdalena Kowalska, Physics Coordinator at ISOLDE, CERN. CaO 11/25 1 to 2 targets built every year Shifts from 2006 to 2011 Microstructure related Material study needed!
12
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Calcium Oxide Production CaO 12/25 Sintering studies show net sintering effects after T>1000 o C
13
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Target Production “Old procedure” ~14µm 99% pure CaCO 3 up to 1200ºC No heating/cooling rates Holding time not defined 10 -3 to 10 -2 Pa No cares taken about CaO exposure to air “New procedure” >5µm 99.5% pure CaCO 3 800 o C 10 o C/min ~48h 10 -3 Pa to 160Pa 13/25 CaO CaO#469 Produced
14
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Target Operation 14/25 Old settings T up to 1200 o C 3x10 13 ppp CaO Initial 25 - 40 m 2 /g 40 - 70nm 33% porosity (~11nm) Final (48h) ~4 m 2 /g 0.3 - 0.5 m 9% porosity (~9nm) New settings T up to 800 o C 8x10 12 ppp Initial >40 m 2 /g <45nm 47% porosity (~20nm) Final (48h) >38m 2 /g <45nm 47% porosity (~20nm) Temperature effect only! Avoid Microstructure Degradation
15
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Online Results CaO 15/25
16
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Ti-based refractory materials PhD subject CERN – T. Stora EPFL – Paul Bowen University of Aveiro – A.M.R. Senos 16/25 Ti-based
17
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Raw MaterialsPressingSintering Sample Porosity (20 – 40%) Characterization: Scanning Electron Microscopy X-ray Diffraction N 2 Adsorption Up to 1450 o C TiC and TiO 2 Material Development 17/25 Ti-based
18
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Proton IrradiationsGamma spectroscopy Heating Cycle RaBIT First annealing heals defects caused by protons TiC and TiO 2 Material Development Ca not enough statistics 18/25 Ti-based
19
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Draft Program Year 2013: Nanometric material synthesis studies with different techniques (core shell material) Sintering studies Further investigation and development of the effusion/diffusion model proposed by Bouquerel Year 2014: Further material studies Online target testing (exotic beams of K and Ca) 19/25 PhD
20
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Uranium carbide nanomaterial development Project of Alexander Gottberg ActILab Collaboration 20/25 Uranium Carbide
21
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Target Material Distribution Actinide targets at ISOLDE in 2011 (2010) 249 shifts out of 396 68% of total (72%) 13 new units (12 new, 2 old) Uranium Carbide 21/25 Slide, courtesy of Alexander Gottberg
22
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE UO 2 + 6C → UC 2 + 2C + 2CO (g) Production Process: 1.Blending UO 2 and C powder 2.Cold pressing into pills 3.Carbothermic reduction of UO 2 two orders of magnitude Development towards highly porous, nano-tailored matrixes: 1.Grinding UO 2 2.Grinding UC 2 3.New synthesis approaches (sol-gel) Uranium Carbide UC material Synthesis / Development In House 22/25 Slide, courtesy of Alexander Gottberg
23
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE µ-spot X-ray fluorescence mapping Uranium Gallium Micro Spot Material Mapping at SLS SEM Uranium 20µm 01 5 243 8 6 7 UC 2 reflex 1 µ-spot X-ray diffraction UC 2 reflex 3 Uranium Carbide 23/25 Slide, courtesy of Alexander Gottberg
24
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Preliminary Online Results Despites the difficulties: 11 Be: 5.3x10 7 1/µC, database: 7x10 6 1/µC Record yields for Cs Structure seems widely conserved over time and temperature Uranium Carbide 24/25 Slide, courtesy of Alexander Gottberg
25
Jo João Pedro Ramos Students'coffee - 16th meeting Nanostructured target materials for intense secondary beam production at CERN-ISOLDE Thank you! Comments and questions? 25/25
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.