Wir schaffen Wissen – heute für morgen Paul Scherrer Institut Preparation of 60 Fe, 44 Ti, 53 Mn, 26 Al and 7/10 Be samples for astrophysical experiments Marin Ayranov, Dorothea Schumann, Rugard Dressler

2 2 OUTLINE  Objectives of ERAWAST  PSI accelerator facilities  Description of the Available Materials  Summary and Outlook  Application Examples 2010 ANS Winter Meeting, Las Vegas 7-11 Nov.

3 3 Objectives of ERAWAST Exotic Radionuclides from Accelerator WAste for Science and Technology 7 Be (53.3d), 10 Be (1.6·10 6 y), 26 Al (7.2·10 5 y), 44 Ti (60.4y), 53 Mn (3.7·10 6 y), 59 Ni (7.5·10 4 y), 60 Fe (2.6 ·10 6 y), 32 Si (172y) 146 Sm (1.03 ·10 8 y), 182 Hf (9 ·10 6 y) Application of exotic long-lived isotopes from accelerator waste  Basic physics research  Geophysics and Astrophysics  Nuclide production facilities  AMS and RIMS measurement groups  Life science and nuclear medicine Difficult, expensive and time consuming production

4 All elements of periodic table with Z ≤ Z target + 1 Production rate Atomic Number Z Spallation Reactions High Energy Accelerator Facilities Cyclotron 590 MeV protons, 3 mA

5 5 Cyclotron: 590 MeV protons 2.2 mA - peak 3 mA Activated parts: SINQ target, BMA-Target, Beam dump, Target E, Shielding etc. Materials: Zirkalloy, Lead, Aluminium, Stainless steel, Copper, Tungsten, Beryllium, Cast iron, Graphite, Concrete, SINQ Cooling Water etc.

6 6 SINQ target STIP 207 Bi, 172 Hf, 173 Lu, 194 Hg, 202 Pb, 205 Pb, 125 Sb, 106 Ru, 44 Ti, 26 Al, 53 Mn Myon production 10 Be Copper beam dump 44 Ti, 53 Mn, 26 Al, 60 Fe, 59 Ni, 32 Si Stainless steel collimator 44 Ti, 26 Al, 53 Mn SINQ cooling water 10 Be

7 SINQ Target Irradiation Program - STIP  Irradiation of samples at special positions V, Mn  Regular production of MBq 44 Ti every two years 2010 ANS Winter Meeting, Las Vegas 7-11 Nov.  350 rods of Pb  SS 316L cladding  specimen rods  Total beam dose 10.3 Ah

8 8  Good Separation from Matrix and Impurities  Selective with High Yield and Carrier-Free Procedure  Simple steps Co-precipitation Solvent extraction Ion exchange  Easy for remote control/automation NI - LabVIEW  Management of the Wastes Acid Liquid Wastes Spent Ion-exchange Resins, Filters etc. Radiochemical Separation Procedure Suitable for Hot Cell Implementation

9 9 Hot-Cell Separation System

10 Summary  Radionuclides separated 7 Be – 10 GBq 10 Be – 50  g 44 Ti – 10 MBq 53 Mn – 2·10 17 atoms 60 Fe – 5·10 16 atoms  Radionuclides available 7 Be – unlimited 10 Be – 100  g 26 Al – 20 kBq (10 18 atoms) 59 Ni – 8 MBq (10 19 atoms) 44 Ti –1 GBq (10 18 atoms) – every two years 53 Mn – 500 kBq (10 19 atoms) – much more available with carrier 60 Fe – 5·10 16 atoms 32 Si – 10 MBq (10 16 atoms)  Possibilities for other irradiation positions (SINQ, beam dumps, collimators)

11 60 Fe half-life and neutron capture cross section Technical University - München, Germany University of Notre Dame – Indiana, USA; GSI Darmstadt; FZK – Karlsruhe, Germany; University of Lodz, Poland; Keele University, United Kingdom

12 60 Fe half-life measurement A - ingrowth of 60 Co N - MC-ICP-MS Phys. Rev. Lett. 103, (2009) T 1/2 = 2.62 ± 0.04 · 10 6 years (1s)

13 60 Fe half-life capture cross section 60 Fe(n,  ) 61 Fe cross kT = 25 keV ‹σ› = 10.2 ± 2.9 syst ± 1.4 stat mbarn ‹σ› = 5.8 mbarn Corrected for the new 60 Fe half life Phys. Rev. Lett. 102, (2009) t 1/2 = 6 min E  = 298, 1027 and 1205 keV I  = 22, 43, 44 % t 1/2 = 1.65 h E  = 67, 909 keV I   85, 4 % Fe Co Ni

14 Explosion mechanism is extremely complex Good diagnostic – 44 Ti Produced in significant quantity Gamma-ray observable – 1157 keV Quantity produced is sensitive to underlying physics 44 Ti abundance determined by only a few key reactions: Triple  40 Ca( ,  ) 44 Ti 44 Ti( ,  ) 48 Cr 44 Ti( ,p) 47 V M1 – The Crab SN1987A Core Collapse Supernovae

15 MC-ICP-MS LSC 10 Be Half-life ICP-MS can measure isotope ratios for the Beryllium isotopes BUT – only one stable Be isotope - 9 Be Second point for mass bias correction - 7 Be quantified by 478 keV gamma line 7 Be (53 d) → 7 Li (stable) ICP-MS in principle possible, but interference with 7 Li, 10 B

16 53 Mn neutrons cross section and half-life determination  Sample material  Copper beam dump, STIP samples, Special irradiation  Sample preparation  Measurements techniques  ICP-MS, AMS, LSC  Cold and ultra cold neutron source Regular 44 Ti production considerable amount of 60 Fe, 53 Mn, 26 Al, 7/10 Be and others available on demand

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