. MOON MOON for  low E  solar ’s. Molybdenum Observatory Of Neutrinos for  low E  solar ’s. Molybdenum Observatory Of Neutrinos Hiro Ejiri JASRI Spring-8, RCNP Osaka Univ. For the MOON collaboration

RCNP Research Center for Nuclear Physics National Nuclear Physics Lab. Nucleon, Meson, and Quark Lepton Nuclear Physics. Ring Cycrotron lab GeV p, & light ions National and International users RCNP laboratory complex

Penta quark baryon  + n = K - + K + + n with n in C,  + n = K - + X  missing mass lead   1.54 GeV with < GeV width u u d d s, s is anti-s Nakano et al., PRL 91, 03,

ELEGANT V  f     Cd  -ray E&T PL  -ray by NaI DM –nucleus recoil E by NaI. H. Ejiri et al. NIM A

Subjects discussed 1. MOON for masses by  Decays and low energy solar ’s. 2. MOON Detector 3. Detector R&D 4. Concluding remarks

1.MOON for masses by  Decays and low energy solar ’s..

MOON Objectives. Neutrino studies in 100 Mo with large responses for  & low E e ’s. A. Double beta (  ) decays with m ~0.02 eV. B. Low energy pp & 7 Be solar e with  ~ 10 % with 1 y H.Ejiri,, Phys, Rev. Lett.,85 (2000) Ru

 schemes   L  M(  ) Res.   L=2 Majorana < m  ＝  m j c j v j 2 Absolute mass scale in eV range of  m  and  m s M 0  is crucial

Energy and Angular Correlations

Effective mass & mass spectra ＝ S m j c j j 2

 &  masses  effective mass > 0.1 eV for quasi degenerate ~ 1 ~ 0.5  m(at) ~50 ~ 25 meV for inverted spectrum. ~0.25  m(sol) ~ 2 meV for normal.  with sensitivities of I. 0.1~ 0.2 eV QD, m 1 > 0.3 eV II. 20 ~ 30 meV give the mass spectrum and m 1 in case of IS III. 1~ 2 meV give mass spectrum in case of NH and m 1 S. Pascoli and S. T. Petcov

Present Status of  for mass Inclusive  128 Te Geo-chemical ( MPI, others) < 1.6 eV 76 Ge H.M. IGEX, Ge Detectors < eV, 130 Te Cryogenic Bolometor < eV Exclusive  spectroscopic studies. 100 Mo ELEGANT, 150 Nd, < 1.5 – 3 eV NEMO will search for ~ 0.3 eV region. All depend on nuclear matrix elements. Limited by the detector sensitivities of S D ~ eV. m -1 ~ M  k(Z) Q  2.5 N  1/2 /[  E N BG ] 1/4 t 1/4 Large Sensitivity: Large Detector with N  ~ tons to get the - mass sensitivity of 0.01~0.05 eV. Next generation  detectors of 0.01~0.05 eV with tons of nuclei 76 Ge, 130 Te, 136 Xe, 100 Mo

Unique features of MOON for  1. Large Q = MeV leads to the large rate  SNU for =  eV the large 0  signal well above RI BG. 2. Excited 0+ by  no 2  RI. 3.  angular correlations to identify the m  term. 4. Localization in space and time leads to high selectivity of S with modest purity of b~mBq/t, ppt.

Raw rate 31/y/ton 100 Mo for 0.05 eV  mass Large Q  = large rate of    SNU for =  meV Large nuclear response for 0  Excited 0+

Decay to the MeV excited 0+ state    Possible shape change leads a larger M 0  Weighted sum of T  for both the 0+ states is less sensitive to the nuclear structures. Excited 0+ state transition with deduced 2   and RI BG by  coincidence T  ~ y * Ratio to the g.s is 0.01 by Q 10, but T  may be 0.1 by Q 5 T   T  is larger by 10 than that for the ground state transition. * DeBraekelee et al, Barabash et al

Large signal above most of BG 100 Mo 0  by ELEGANT V < 1.5 (2.0) eV H.Ejiri, et al., Phys. Rev. C 63 ’01,  eV, above most of U-Th natural and cosmogenic BG RI’s. Low BG < / keV / kg /y. Effective ( BG  E) 1/2 ~ 1.2 same as present Ge ( 0.8). Effective Signal ~ 10 larger. Main BG  Ge 0.2 / keV / kg / y

Unique features for solar Unique features for solar 1. Large CC rates with low Eth 2. GS: pp- and 7 Be-  B(GT) from EC. Ratio of pp/ 7 Be  is independent of the B(GT). 3.Real time studies of CC 4.The two  (charged particles) coincidence to localize signals in space & time to cut RI,  G. 5. Complementally to GNO, BOREXINO, LENSE.

Solar   oscillation and solar process SK, SNO, Gallex- SAGE, Cl No low E real-time CC of major pp and 7Be  Sensitive to  mixing angle as well.

Raw rates /one ton 100 Mo /y are 40 for 7 Be- and 120 for pp-

Solar pp & 7 Be Ga (CC) = a pp(72) + b 7Be(35) + c 8B(13) + CNO a,b, ~ 0.6 for LMA 8B(13) from SNO/SK but need Ga response for 8B (CC). MOON will give 7Be (CC) with 7 % of LMA, i.e.  ~ 1.5 SNU, which leads to  ~1.5 SNU for pp, i.e. 2 % of 69 (pp-SSM). If GNO will improve pm 4 SNU. Ga and MOON give pp neutrinos with ~ 5 SNU of SSM S(pp)=69 SSM Gallex/GNO MOON S( 7 Be)=35. MOON and Borexino 7 Be (CC) + 7 Be (NC) will give 7 Be (NC)

2. MOON Detector

Requirements for MOON Large volume/mass of 100 Mo M~ ton Centrifugal separation NIIEF Two  coin.  t ~ns for ,  t~1-30s solar-  Dynamic range E  ~ MeV Energy resolution  ~ 0.03~0.05 /(E MeV) 1/2 2~3 % for 3MeV 0  and 15 % for pp- Position resolution 1/K ~ 10 –6 ton ~ 2cm for  ~10 -9 ton ~ 2 m m for solar Purity ~ 0.1 ppt Bq/ton for U, Th isotops.

Signal selection by localization of signals in 4-dimentional space-time in detector A. SSSC :Signal Selection by Spatial Correlation  P ~ (  x ~ 1 cm /2 m) 3 10 –8 / m 3 1 MeV  range 8 cm  Signal is   or solar  followed by  Single-successive sites 2 ~ 6 cells BG  e E0 - IC X ray Compton e   Multi separated sites SSSC reduces most of RI’s BG,  by 1-2 orders.   e 

SSTC Signal Selection by Tim Correlation B A Single site for  2 sites within 30 sec for solar  followed by  Time correlated pre- and post decay signals, B’ and B’’. Time window T ’ < < 1/all event rate / unit cell detector: High K = 1/  P ~ and modest low / purity of S-BG rates : b < 10 –3 Bq / ton reduce by 2 orders of magnitude of natural and cosmogenic RI’s with T B 1/2 < 2.5 ( K / b ) ~days. Time coordinate T T’  T’ B’ B B’’  ’  ”

Hybrid detector  o film Scintillator plate 6 mm Fiber XY Super module of Mo films and fiber/plate scintillators. 1. Position read-out by fibers with 4mm - 4 mm mm 2. Energy read-out by  dimentional plane scintillator with E resolution  ~ 2 % FWHM ~ 4.5 % including the Mo film. 3. Modest volume with enriched Mo and modest cost of MA / PM 4. One unit 2m – 2m – 2 m : 240 modules Mo 0.25 ton. PM-3inch : 3K. MA-PM :7K One module 2 m–2 m–8 mm Fiber xy plane

MOON Plastic fiber-Mo Ensemble Scintilation Fiber Mo 0.02g/cm 2 2 sets of x- y fiber planes Mo(20mg) Plate scintillator

Energy and Position Resolution Plate PL scintillation plate Fiber PL scintillation fiber BCF12Mc 0.4 mm Sq, 435 nm E = E p + E x + E y plate, x and y fibers Plate  (E p ) = (1 /N e ) 1/2 E -1/2 = 4 % E -1/2 with E in MeV, Fiber  E x ) = (1 /N e ) 1/2 = 6.3 % E -1/2 with E in MeV,   = 2.3 % for 3 MeV,  e   = 4.8% for 0.7 MeV, Mo: 20 mg / cm 2 = MeV FWHM = ( 0.41) = MeV neglect. Position: Binding 10 fibers,  x*  y = 0.4 * 0.4= 0.16 cm 2 = –9 gr.

Sensitivities &  rates Detector N(Mo) y t ½ y eV N 0   N 2 ELEGANT V 0.2 kg 1.5y < MOON I 1kg 3 y MOON II 0.25 t 3 y MOON III 1 t 10 y Excited 0+ state Mo with 85 % 100Mo Sensitivity is given by (N 2 )½ = N 0

T 1/2 y m(BC) eV m(DEF) eV MOON MOONII MOON III B:Rodin-03 QRPA, C:Rodin-03 RQRPA, D:Simkovis01 QRPA E:Suhonen02 QRPA F:Faessler98 RQRPA

Solar sensitivity pp- 7 Be- Raw yield / 1 y ton LMA Yield after cut / y t BG  cut y t < 1   G 214 Pb-Bi / cut y t ~1 ~1 MOON III Yield / 6 y t Statistic      y t  T   y,  / t    Pb-Bi 0.1 ppt 20 min. with post  gr range)

Enriched 100 Mo isotopes VNIIEF is ready to produce 1 Kg immediately, and 0.1 t / y soon. Rate 0.5 t 100 Mo/ 5 y with 12 t n Mo with 6 K centrifuges enrichment 85~ 95 % with 40 processes..

G.Shirkov, Joint Institute for Nuclear Research, Dubna, Russia Basic characteristics of available isotope production with centrifugal technology at VNIIEF: The project was developed in The developer of technology of zinc isotope separation – “GAS” and VO VNIIEPT The planned production capacity  8000 machines The isotope separation section area m2; % of enrichment 2 production rate

3. Detector R & D

Energy resolution and efficiency EL V MOON ( Flat bar) ( Flat plate) 1 m *15mm 2m *12 mm N pe / MeV 12 K 12K Transmission Attenuation   (pe) PM N pe / MeV  eV 4 % 4 %  eV 2.3% 2.3 % t for n 1 = 1.58, n 2 = 1.0 Two dimension square 0.63 * 0.9 Source effective thickness 35 keV  ~ 11 keV ~ 0.4 % for each  neg.

Plate scintillator 137 Cs 662 keV Compton 90 pm 10 photoelectrons MeV * 8 K * 0.21 PM coverage * 0.55 * 0.2 pe rate = 85 pm 9

. Energy resolution test mm PL plate with 4-2inch PM Cs 480 keV Compton electron N pe (cal) = 0.48 * 0.65 * 0.22 = 680 ~ N pe (exp)  = 2.7 % /E 1/2 from the photon yield.  = 2.7 % /E 1/2 from the Compton edge resolution. PM PL

Position resolution mm with 4mm PM anode 5mm 2

 sum spectrum and efficiency 6 t y 100 Mo Half life ~ eV M =  (FWHM 7%) 0 g. E, E, >0.5 MeV, 2-hit. Efficiency 0 0.7* 0.4 =  eV    eV

Sensitivity : Half life limits and Mass B:  = 3 %, C:  = 2.2 %, B:M=3,  = 3 % D:M=3,  = 2.3 % MOON 1 N = ty, MOON 2 N = 0.75 t y MOON 3 N = 10

7 Be solar 700keV  Sum > 60 keV of up and down fibers 1, 2, and PL’s gives 89 %.

Solar from 7 Be and 2  accidental rate & position 1/K D: No osci. C: LMA B: 2  A. 1/K= ton with 20mg/cm 2, 4mm*4mm

BG and purity Major BG Bi ground state decay b: Bq/ton b = 125 ppt for 0.1ppt b ~ 0.02 Bq/t present NEMO level Tl excited state decay Position resolution of the 0.5mm*4 mm fiber is assumed, 10mm thick plate is enough

MOON 1. Prototype MOON. 0.3 eV with 1 kg Mo. MOON 1. Prototype MOON. 0.3 eV with 1 kg 100 Mo. ELEGANT V Position Energy EL V Drift chamber PL scinti. bar MOON Fiber plane PL scinti. Plate

Summary Mo with the large responses for  gs, excited 0+), solar-, and sn- are used for studies in Mo micro labs. 2. MOON(Mo Observatory Of Neutrinos) : realtime two  spectroscopy for  with Majorana sensitivity of m ~0.03 eV low E solar ’s by inverse  tagged by successive  3. MOON is a super module of Mo/ 100 Mo & scintillators with modest volume(10 m 3 ) and realistic purity(0.1ppt). High position resolution and adequate time window for two  rays reduce all kinds of correlated and accidental BG. 4. Enriched 100 Mo can be obtained by centrifugal separation. 5. MOON detector is used for any external sources and others.

MOON collaboration. H.Ejiri*, R. Hazama, T.Itahashi N.Kudomi, K.Matsuoka, M.Nomachi, T. Shima, Y.Sugaya, S.Yoshida. RCNP, and Physics, Osaka Univ. P.J.Doe, T.L.McGonagle, R.G.H.Robertson*, L.C.Stonehill, D.E.Vilches, J.F.Wilkerson 、 D. I. Will. Phys. CENPA, Univ. Washington. S.R.Elliott, LANL J.Engel. Phys.Astronomy, Univ. North Carolina. M.Finger, Kuroda, Phys. Charles Univ. K.Fushimi, General Arts Science, Tokushima Univ. M. Greenfield, ICU, Tokyo. A.Gorin, I.Manouilov, A.Rjazantsev. High Energy Physics, Protvino. A. Para FNAL A. Sisakian, V. Kekelidze, V. Voronon, G. Shirkov A. Titov, JINR V. Vayulin, V. Kutsalo, VNIIEF * Contact persons

Thank you for attention Welcome to the MOON collaboration to give rise to

References Nuclear responses for neutrinos. Review H.Ejiri, Phys. Rep. 338 (2000) 265. GR and , solar & sn ’s  H.Ejiri, Nucl. Phys. A 687 (2001) 350c 71 Ga by 3 He,t reactions H. Ejiri, Phys. Lett. B433 (1998) Mo by 3 He,t H.Akimune, H.Ejiri, et al. PLB 394 (1997) 23. Double beta decays and neutrinos.  L V  H.Ejiri, N.Kudomi, et al., Phys. Rev. C 63 (2001) Review H.Ejiri, Nucl. Phys.B 91 (2001) 255, v2000 proc MOON  -solar  H.Ejiri, R.G.H.Robertson, P.R.L,85 (2000) 2917 Supernova  H.Ejiri, J.Engel, N.Kudomi, PL B 55 (2002) 27 SSTC & Detector H. Ejiri, et al., Nucl. Phys. Proc. PANIC 02

 with sensitivities of ~ 0.2 eV >  m a =50meV QD, m 1 > 0.1 eV Current experiments ~ 30 meV <  m a NH / IH, and m 1 in case of NH Near- future experiments 3. 1~ 2 meV < 0.25  m s = 2 meV NH, and m 1 Far-future experiments S. Pascoli and S. T. Petcov

.

Energy resolution and Efficiency EL V MOON ( Flat bar) ( Flat plate) N pe / MeV 12 K 12K t both end  (pe) PM N pe / MeV  eV 4 % 2.6 %  eV 2.2% 1.5 % t for n 1 = 1.58, n 2 = 1.0 two dimension square 0.63 * 0.9 Source effective thickness 40 keV  ~ 10 keV ~ 0.3 % for 

Cosmogenic RI’s at Underground Lab.  -rays followed by , anihi.  are rejected by spatial correlation. Most of  nuclei are produced 1h before by (n, n p  ) reactions, which are eliminated by p,  and X ray in case of EC

 accidental coincidence rate at 7 Be-n Accidental coincidence of two  events in a 30 sec of  t. T 2    y (t ½ ) y, Y = / y/ t. Y AC =      t / K =     / K /y / t, where  t = 30 sec = y is used. Efficiencies are   = for Be7- window, where (  E = 20 keV) and 0.25 (angular distribution cos  for 0.7 MeV)       for  Tc  window  where  > 0.6 MeV) and  0.2 (angular distribution cos  for 1 MeV   = Y AC = 0.3 / y / t, << Be7- rates of Y ~ 22/t/y for LMA

Solar BG     y t   T  sec =   y,  / t   with 2mm  2 mm * g / cm t,   with 0.01 for  sum energy in the pp-  window and 0.3 for two  in the same side.  . 214 Pb- 214 Bi 0.1 ppt 1.25 m Bq / t Y = 3.9  10 4 /y /t = 1.6 /y /t for RI from MO  = 4 10  with 30 sec T window for 20 min. life, 0.2 for 20 % branch of the gs 3 MeV  gate 0.02 with E window of pp-  for 1 MeV   for  post  gr range) BG for RI from PL& fiber is smaller: weight is a factor 4 but  both  can be detected for SSTC.

G.Shirkov, Joint Institute for Nuclear Research, Dubna, Russia STABLE ISOTOPES PRODUCTION Federal Nuclear Center All-Russian Institute of Experimental Physics (VNIIEF) man The technology developed at the “GAS”, Nizhny Novgorod. Isotope product with a centrifugal technology using serial gas centrifuges. At present, is zinc oxide. Processing lines include about 2000 centrifuges.

 spectrum with 10 t y 100 Mo with PL 。  eV    ~ 0.05 eV RQRPA (Volonon/ Tubingen).  Left 0.05 g / cm 2 and right 0 g. Peak shift 70 KeV 0.05 eV

MOON Objectives. MOON Objectives. Neutrino studies in 100 Mo with large responses for  & low E e ’s. Double beta (  ) decays with m ~0.03 eV. Low energy pp & 7 Be solar e Two charged particle (  ) spectroscopy with high localization(resolution) in time and space. MOON, a super module of ~1 ton 100 Mo & scintillators with modest volume and realistic purity. H.Ejiri,, Phys, Rev. Lett.,85 (2000) 2917