Status of 40 Ca 100 MoO 4 single crystals growing for AMORE Collaboration Presented by V.N.Kornoukhov on behalf of: ITEP, INR RAS, BNO INR RAS, JSC NEOCHIM, JSC FOMOS-Materials (List of participants: see next page) Daejeon, Korea October 8-9, 2010

List of organizations and participants ITEP: V.N.Kornoukhov, N.Khanbekov, P.A.Polozov JSC NeoChim: A.E.Dosovitsky, A.L.Mikhlin JSC FOMOS-Materials: O.A.Buzanov MSAI: A.N.Annenkov INR RAS: I.R.Barabanov, V.I.Gurentsov Baksan Neutrino Obsevatory INR RAS: K.V.Efendiev, A.M.Gangapshev, Yu.M.Gavryluk, A.M.Gezhaev, V.V.Kazalov, V.V.Kuzminov, S.I.Panasenko, S.S.Ratkevich, S.P.Yakimenko

Main CaMoO4 single crystal properties Т melt = 1445 о С (Pt or Ir crucible needed !) Technology: Chochralsky method High Light output > 2500 photon/MeV Kinetics of scintillation (main component): at room temperature = 16 mksec at 6 К = 345 mksec

CaMoO 4 single crystal growing in Russia: Short Recent History Beginning: Autumn, 2003 ITEP and School of Physics, SNU (KIMS Collaboration) Project ISTC 3293 (March 2006 – May 2007) ITEP (Leading organization) MSAI (&Bogoroditsk Plant, Russia) IPN, Minsk (Belorussia) School of Physics, Seoul National University (Korea) Federal Aiming Program (August 2008 – October 2009) JSC FOMOS-Materials (Moscow) IMTM RAS (Chernogolovka, Moscow region) ITEP (coordination) Project ISTC 3893 (May 2009 – January 2010) ITEP (Leading organization) MSAI (Moscow) JSC FOMOS-Materials (Moscow) Seoul National University (Seoul, Korea) Kyungpook National University (Daegu, Korea)

Technology of CaMoO4 single crystal growing Raw material preparation - Preparation of chemicals and chemical utensils - Purification of Ca- and Mo- components - CaMoO4 raw material synthesis, drying and calcination Melt (compactization) of raw material Czochralski growing of raw CaMoO4 single crystals Czochralski growing of finished CaMoO4 single crystal and initial annealing (killing) Principal annealing under high temperature into oxygen atmosphere Cutting, lapping and polishing to form scintillator element

Czochralski method of CaMoO4 single crystal growing There are two approaches of implementation of Czochralski method (CaMoO 4  T melt = C) : - pulling into air/atmosphere using crucible made of Pt (T melt = 1769 o C) - pulling into argon atmosphere using crucible made of Ir (T melt = 2454 o C) FOMOS-Materials made R&D on both approaches. Our choice is a crucible made of Pt (D90 x 70 mm)

Working chamber: Ø = 600 mm H = 1200 mm L (puller rod way) = 500 mm Heating: low frequency RF coils Total mass = 3500 kg Puller “CRYSTAL 3M” (FOMOS-Materials)

Analysis: ICP MS & AES MS (Analytical Center of IMTM RAS) Pre-concentration (extraction of Mo-matrix) a) autoclave decomposition into 1 mL HCl and 0.1 mL HNO 3 under 160 oC b) extraction of Mo-matrix Content of Li, Be, Na, Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Zr, Mo, Nb, Rh, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Ir, Hg, Tl, Pb, Bi, Th and U have been determined by an mass spectrometer with an inductively coupled plasma (Х-7, Thermo Elemental, USA) Sensitivity on U-238 is up to 0,07 ppb and on Th-232 is up 0,1 ppb

HPGe measurements at Baksan Neutrino Observatory INR RAS

Main results (February 2010) 100 MoO 3 purity ( 226 Ra < 2,3 mBq/kg, 228 Ac < 3,8 mBq/kg, 238 U < 0,07 ppb, 232 Th < 0,1 ppb) produced by the ECP for the FAP is good 40 CaCO 3 purity ( 226 Ra = 260 mBq/kg, 228 Ac = 160 mBq/kg, 238 U < 0,07 ppb, 232 Th < 0,1 ppb) produced by the ECP for the FAP is not good ( 226 Ra& 228 Ac !) Good purity of Calcium Formate purified by JSC NeoChim was proved ( 226 Ra < 1.7 mBq/kg, 228 Ac < 1.6 mBq/kg) Purification coefficient impurity of double crystallization Czochralski procedure was defined at level of K (Ra-226 ) >= 35

Synthesis of CaMoO 4 raw material at NeoChem (Moscow) There are two techniques to synthesize CaMoO 4 raw material (charge): 1.solid-phase synthesis of the oxides (CaO and MoO 3 ) mixed into stoichiometric ratio 2.Co-precipitation reaction

Synthesis of CaMoO 4 raw material at NeoChem (Moscow) Co-precipitation reaction: (NH4) 6 Mo 7 O *Ca(NO 3 ) 2 + 8*NH 4 OH   7*CaMoO *NH 4 NO 3 +4*H 2 O -guaranteed stechiomery -additional purification in the process - NH 4 OH and NO 3 are easy can removed by washing and heat treatment Now new Ca-compound (calcium formate): (NH 4 ) 6 Mo 7 O Ca(HCOO) NH 4 OH   7 CaMoO NH 4 (HCOO) + 4 H 2 O

40 Ca 100 MoO 4 raw material JSC NeoChem After melt at FOMOS-Material

Method of isotopes separation

Location of main producers of stable isotopes in Russia

Mo100 production: Gas centrifuge method

Mo-100 isotope production: The ECP (Electrochemical plant) Zelenogorsk, Krasnoyarsky kray, Siberia 100 MoO 3 oxide with mass of Mo-100: gr gr = 2,5 kg Enrichment: Mo-100 = 96,1% Impurities ( the results from ICP MS measurements ): U <= ppm (< 0,07 ppb) and <= ppm (< 0,2 ppb) Th <= ppm (< 0,1 ppb) and <= ppm (< 0,7 ppb) 226 Ra < 2,3 mBq/kg, 228 Ac < 3,8 mBq/kg

ISTC3893: New portion of 100 MoO 3 Portion of 100MoO3 (100 gr of Mo-100) has been ordered ITEP from ECP to use it in following crystal grow procedures to compensate change of stechiometry during crystal pulling. It will be delivered in October 2010.

Production capacity of Mo-100 at the ECP Current capacity is 0,6 kg of Mo-100 per month (7-8 kg per year). It is important to emphasize here that any increase above the current production capacity will require additional investment in plant (in the form of increasing the number of centrifuges committed to Mo-100). Moreover, a commitment to large-scale expansion of molybdenum production would not be made lightly. The reason why is quite important. The working gas for Moly enrichment (MoF6) is extremely corrosive. Enrichment of most other isotopes can be interchangeably performed on the same equipment. With Moly, once a machine is dedicated to Moly enrichment, there is no going back. You simply scrap the machine when the program is completed. ITEP received preliminary assurances that a scale-up of current production is planned because of worldwide shortage of Mo-99 for Tc99m generator production. Comment. Mo-99 is produced as one of fission product by reactor irradiation of HEU (U- 235) with the yield of 6% using mainly NRU reactor (Canada) and HFR reactor (Netherland) is under question). Operation of these reactors NON stable (they are 50 years old!). New proved technology: production of Mo-99 in the activation reaction: 98Mo(n,g)99Mo So New investment in plant & equipment will begin the nearest future. As result, new productivity will about 2,4 kg of Mo-100 per month ~ 28 kg per year

Ca-40 depleted on Ca-48: motivation

Principle of electromagnetic separation of stable isotopes The coefficient of the feed material utilization for EM method is in the range of 2 – 20% only The coefficient of utilization for Ca isotopes is 4,5% Dispersion d of the EM facility (a distance between ions beams): d = 2  R = R(  M/M) A value of d for Ca isotopes (SU 20 facility) is about 25 mm 2R = 1800 mm Source Receiver H – magnetic field Dispersion d is a distance between ions beams) d

The industrial separator SU20 Lesnoy, Sverdlovky region 27 kg of Ca-40 ( 40 CaCO 3 ) is available now at EKP, Lesnoy Ca-48 < 0,001%

Electromagnet of the SU20 separator (5-floors building & 3000 ton magnet!)

SU20: Separation tank (2*2*5 = 20) U = 30 kV R = 90 cm

Ca-40 isotope production in Russia Electrochimprobor Lesnoy, Sverdlovk region 40 CaCO 3 compound with mass of Ca-40: 587,58 gr gr = 1,25 kg Enrichment: Ca-40 = 99,964+/-0,005% Ca times) Impurities U <= ppm (< 0,2 ppb) Th <= ppm (< 0,8 ppb) Sr = 0,0033% = 25 ppm Ba = 0,0035% = 26 ppm * i n blue – the results from ICP MS measurements

Samples sent to ELEKTROKHIMPRIBOR to check possible isotopic “dilution” effect during initial preparation and crystal growing #1 Raw material 40 Ca 100 MoO 4 from JSC NEOCHIM #2 single crystal S 27 #3 single crystal SB 28 #4 melt after SB 29 growing* (*) will be analyzed soon

No isotopic dilution of Ca-48 (and Ca-46) was observed!

ELEKTROCHIMPRIBOR June 2010 New batch of Са-40 ВП-2-10 for characterization at Baksan Neutrino Observatory New chemistry which should be proved after Ra-226 measurement at Baksan: Weight of the 40 CaCO 3 butch (Ca element): 210,0379 gr. Isotopic composition: 40 Са – 99,988 % ат. + 0,003% at; 46 Са - < 0,001% at. Impurity: Sr – 0,0007% mass (instead of 0,033% before) Ba – 0,0007% mass (instead of 0,035% before) Mg – 0,0003% mass Mn – 0,0001% mass In total – 0,0018% mass

Isotopic composition of Ca-40 (new batch)

40 Ca 100 MoO 4 single crystal before annealing (m = 0,55 kg, D49 x 42 mm, L cylinder = 53 mm grown 11/09/2009)

Boule (singe crystal) S35_25_

Scintillator element 40Са100МоО4_S35

S 35: Attenuation length, cm -1

Transmittance, L = 90 cm at 530 nm

Light output of S 35 S35 Resolution : 16% (FWHM) Mean : 5.97 x 10 5 CMO_3 Resolution : 16% (FWHM) Mean : 6.79 x 10 5 SB28 Resolution : 30% (FWHM) Mean : 2.88 x 10 5

Present and Future: Today we run together with SNU (S.K.Kim) and KNU (H.J.Kim) new ISTC 3893 project (May 2009 – Junuary 2011 (after extension)) ITEP (Leading organization) FOMOS-Materials (Moscow) MSAI (Moscow) School of Physics, Seoul National University (Korea) Department of Physics, Kyungpook National University (Daegu, Korea) Main goal: First growth of the Ca 100 MoO4 monocrystals with Mo-100 for neutrinoless double beta decay search in YangYang underground laboratory

Calcium Molibdate Crystal growth process at Fomos-Materials Co. Process stages: 1.Initial powder charge analysis at The Institute of Microelectronics Technology and High-Purity Materials of the Russian Academy of Sciences 2.Pelletizing of the initial powder charge – weight of one pellet 550 g 3.Weighting of initial charge and doping МоО pellets and up to 3 mass. % МоО 3 4.Assembling of crystallizer 5.Growing of initial crystallized charge – crystals up to 550 g each 6.Weighting of initial crystallized charge – only cylindrical parts of initial crystals 7.Growing of end-crystal 8.After growing heat treatment of end crystal – heat treatment in oxidizing atmosphere 9.Mechanical treatment of end-crystal (cutting, lapping, polishing) – produce of end-product according to specification

Crystal growth process scheme One-by-one PelletsCrystallized initial charge preparationEnd crystal growing 1.High purity 2.Small quantity of initials Only cylindrical part

Crystal growth process scheme Parallel PelletsCrystallized initial charge preparationEnd crystal growing 1.Higher purity 2.More initials Only cylindrical part

Crystal growth setup upgrade New control Unique soft Modern hard Energy-saving power supply Power - 60 kW Stability within-  0.05% New upper stock drive arrangement Crystal growth facility at Fomos-Materials Co.

Fomos-Materials Co. crystal growth potential Fomos-Materials Co. has 15 crystal growth stations (6 established and 9 in stock) One crystal growth station can produce at least 18 end-crystals per year up to 600 g and 48 mm in diameter each. Fomos-Materials has 3 high temperature (up to 1600 dag. Cent) furnaces Carbolite 16/35 type for crystals heat treatment Fomos-Materials Co. has all technological equipment for crystal mechanical treatment (cutting, lapping, polishing)

Inventory of 40 Ca 100 MoO 4 –It was received initial powder “C”-grade –4.96 kg –Pellets produced – 10 pcs total weight– g –initial crystallized charge produced No25С – g No26С – g No27С – g,No33C – g, No34C – g, No35C – g total weight – g –Crucible scraps after initial crystallized charge production– g –Pellets leavings – g –Collected deposited volatiles – g –End crystals grown – No28СБ – g and No29СБ – g total weight – g –Crucible scraps after end crystal growing- approximately 520 g (not extracted yet) mass-balance (initials and crystallized charge): Initials – 4,96 шихты Crucible scarps– 899,32 гр In crystallized charge – 3862,31 гр Pellets leavings – 138,86 гр Collected – 33,17 гр Losses (analysis, spillover, waste, fumes): 4,96 –0,899 –3,862 –0,138 –0,033 = 28 g

Conclusion (1) In the framework of ISTC 3293/3893 and Federal Aiming Program ITEP-JSC FOMOS has developed the technology of 40Ca100MoO4 crystal growing: * Mass of single crystal – up to 0,6 kg * Diameter up to 48 mm * Good radiopurity (single crystal before scint. element preparation) < 2,4 mBq/kg (Tl-208) and < 6.4 mBq/kg (Bi-214) * No isotopic dilution of Ca-48 (and Ca-46) was observed! * Low loss (single crystal before scint. element preparation) Mo-100 isotope can be produced at ECP (current productivity is 8 kg per year and 28 kg per year soon after upgrade of Mo facility) 27 kg of Ca-40 (in the form of “primary” 40CaCO3 carbonate) is available at ELEKTROKHIMPRIBOR (EKP, Lesnoy, Sverdlovsk region)

Conclusion (2) EKP has developed new technology of 40 CaCO 3 purification of Ra (Sr, Ba): k ~ 50 times FOMOS has improved transparency of single crystal (Transmittance 15 cm  90 cm at 530 nm) FOMOS has done crystal growth setup upgrade Portion of 100MoO3 has been ordered ITEP from ECP to use it in following crystal grow procedure to compensate change of stechiometry Job planned to be done soon: * Radiopurity measurements at Baksan Neutrino Observatory of new batch of 40CaCO3 (800 gr) produced at EKP by new purification technology * New 40Ca100MoO4 crystal pulling with new equipment and new portion of 100MoO3 for correction of stechiomentry

Back up slides

How we grew SB28, SB 29 and S Ca 100 MoO 4 element for YangYang