Enriched Isotopes for Astroparticle Physics

1. Rare Isotopes (Enriched Isotopes for Astroparticle Physics) Ezio Previtali INFN and University of Milano Bicocca Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

2. Rare Isotopes Candidates Double Beta decay experiments *F.T. Avignone II et al., New Journal of Physics 7 (2005) 6 Dark Matter experiments Ar element depleted in 39Ar isotope (under test) Odd nuclei for spin dependent measurements (?) Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

3. Actual situation for DBD experiments

4. DBD near future New generation double beta decay experiments detector mass larger than 100 kg highly enriched in bb candidates Some example: CUORE 130Te natural ~600 kg Gerda III 76Ge enriched 86% ~1 ton Majorana 76Ge enriched 86% ~180 kg SuperNEMO 82Se/150Nd enriched 90% ~100 kg MOON 100Mo enriched 85% ~100 kg EXO I 136Xe enriched 65% ~200 kg EXO II 136Xe enriched 65% ~1 ton SNO++150Nd enriched 90%~560 kg ……… During the next years there will be a large request of enriched isotopes Production must be clean, flexible (many different nuclei) and fast The production mass scale change from few kg to few hundreds kg Cost estimates for all enrichments > 100 M€ (actual prices in Russia with UC) Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

5. DBD medium term Actual proposed experiments can explore only the inverse hierarchy for mν To go further we need more DBD mass and less background Experiment strategies indicate possible future steps Same setup can measure different isotopes: CUORE , …. Same detector can be multiplied few times Xe experiments, …. New techniques are under developments Scintillating Bolometers, …. New request of isotope production will begin when actual experiments will start Experimental mass for each experiment can, in principle, grow in the range of 1 ton Possible timescale for new experiments ~15 years Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

6. t1/20nsensitivity measuring time [y] detector mass [kg] detector efficiency isotopic abundance atomic number energy resolution [keV] M t a.i. 0 meas S background[c/keV/y/kg] 1 2 A E bkg Production quality Very pure isotopes are necessary Normal enrichment production is not so clean After enrichment a purification process is normally needed A general rule will be: Increasing a.i. without increasing background Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

7. Production quality Background will be very critical: “old” experiments had background in the range of 0.1 counts/(keV kg y) future experiments are going to the range of 0.001 counts/(keV kg y) Purification will be of primary importance and needs precisely evaluations technically and economically A specific example: For MiBetaII experiment we produced 1 kg enriched Te (130Te) Enrichment level was 94% at the production site Material was delivered by the producer in form of TeO2 TeO2 crystals was grown at SICCAS (China): Material was purified few time: it was full of Si Growing procedure was repeated in order to purify the material After growing processes we obtain: Crystals of TeO2 for a total mass of 800 g Level of enrichments at 73% Background around few 10-12 g/g in U and Th (10-13 g/g in natural crystals) Cost for enriched crystal production was ~3 times larger respect to natural Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

8. Actual production capability USA: Calutron production was stopped in 2004 Medium size ICR machine founded by DOE is installed at Theragenics production is oriented to medicine application New program for AVLIS founded at Livermore (very expensive) it is unclear if this program will be completed Russia: Few labs are able to produce isotopes with Ultracentrifuges Only elements that have gas compounds can be produced Prices of enriched isotopes are favorable (today) Europe and Japan: There are some enrichment facilities based on Ultracentrifuges Restart of an AVLIS machine in France is not yet established (150Nd) Actually practically only Russian labs can produce stable isotopes Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

9. Possible future strategy (1) It is possible to find an agreement with Russian producers Advantage: - Enrichment plants exist - Actual prices per unit product are low - They have a lot of experience in UC technique Disadvantage: - Only isotopes with UC will be produced - It is not clear at which level can be done an R&D program - Produced materials are normally dirty and need purification - What about future prices? Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

10. Possible future strategy (1) Cost enriched Te for CUORE 12 April 2005 • Te-130 in form of metal: • Mass - 250 kg • Enrichment - > 99% • Purity > 99.9% • Cost – 9.9 $/g (at FCA, Krasnoyarsk condition) • Time 400 days (> 99%) 350 days (> 90%) New quotation was asked from USA group of CUORE October 2007, CUORE meeting at LNGS, F. Avignone report New Cost - 13.0 $/g (indicative) Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

11. Possible future strategy (2) It is possible to restart some production plants in west countries Examples: - AVLIS (SILVA) in France (CEA) is under discussion - USA plants with UC and AVLIS (not realistic) - URENCO machines (UC) in Europe (Prices probably too high) - Discussion with Theragenics for possible use of ICR machine Advantages: - Different sources of production respect to Russian one - R&D programs will be probably much simple - It is possible the production of more isotopes (150Nd using AVLIS or ICR) Disadvantages: - Restart decision must be taken as soon as possible - Some plants are not flexible (AVLIS in France can produce only 150Nd) - Some plants are dedicated to other productions (medical application) - In general production throughputs are not enough (a part AVLIS) - Actual production cost are 10/100 times larger then Russian Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

12. Possible future strategy (3) It is possible to realize a dedicated plant in EU. New plant must be configured for: - Flexibility: a maximum number of isotopes must be produced - Clean: a clean production and an integrated purification system are needed - Cheap: production cost must be comparable with the Russian one - Dedicated: possible R&D programs on specific isotope can be possible Advantages: - Production can be configured as requested from the experiments - Specific isotopes production can be studied (150Nd and 48Ca) - Cleaning procedures can be made in place Disadvantages: - Plant doesn't exist and it must be realized - It is necessary an agreement will all the involved experiments - Decision must be taken soon, time is practically over - Initial investments are not negligible Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

13. Possible future strategy (3) We proposed last year to built an enrichment facility based on an ICR machine: flexible to produce most of the interested DBD isotopes 48Ca, 76Ge, 82Se, 100Mo, 150Nd, … throughput : >100 kg/year for various isotopes realization time: 4/5 years The facility can be realized with: Large current separator ICR machine Low current separator Calutron Chemical support Clean Room, Chemical Labs,.. Cryogenic support LN2 and LHe, (liquefier?) Analytical systems ICP-MS, .. General support UPS, mechanical, … There is, actually, no real agreements to work in this direction Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

14. Conclusions Production of Rare Isotopes will be a crucial issue for future experiments Production capability must be clearly evaluated technically and economically Actual production cost (for enrichments) is favorable, for the future ……. Purification of enriched nuclei must be considered as a very important aspect Analysis must be done on short and medium timescale It is very difficult to define an agreement between different experiments Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

15. Ion Cyclotron Resonance separation from: G. Yu. Grigoriev, Kurchatov Institute, Moscow Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

16. Production costs This infrastructure will be competitive with present production in Russia? As our knowledge actual prices are (examples): 76Ge ~60 €/g 82Se ~120 €/g For these elements we evaluate a general cost between 40 and 80 €/g But the proposed infrastructure will be not a production facility Scientist can directly participate at source preparation Production can be, in principle, tuned to fulfill experimental request Moreover it is possible to enrich also nuclei like 48Ca and 150Nd Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008

17. By-products Many enriched isotopes for various application can be produced Some of these cannot be massive produced with other techniques Some examples: Medicine (diagnostic and therapy) 112Cd, 50Cr, 102Pd, 58Fe, 203Th, …. Industry 157Gd, 64Zn, 90Zr, 58Ni, 54Fe, 97Mo, …. Research 43Ca, 44Ca, 48Ca, 50Cr, 58Ni, 76Ge, 82Se, 100Mo, 150Nd, 168Yb, … The main advantage of this approach is Flexibility Aspera meeting on “R&D and Astroparticle Physics”, Lisbon 8 January 2008