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scintillation scintillation crystals and the AMoRE is studying the 126 1

l International Conference on High Energy High Conference (ICHEP2018) on Physics International two [email protected]

NonCommercial - The Center for Underground Physics (CUP) at the Institute for Basic Science (IBS) has been been has (IBS) Science Basic for Institute the at (CUP) Physics Underground for Center The otmnto drn te rsa got. ee w rpr te rsa growth crystal the report we Here, growth. crystal the during contamination background internal odcig w mjr xeiet, h CSN eprmn fr ak atr erh n the and search matter dark for experiment COSINE the experiments, major two conducting for neutrinoless do experiment AMoRE NaI:T CaMoO as the Abstract mail: mail: 11July, 2018 Copyright owned by the author(s) under the terms of the Creativeauthor(s)the termsthe underthe of Copyrightbyowned Commons -

- Speaker 1 ã Attribution 39th The 4 Korea Seoul,

Department of Physics, Kyungpook National Kyungpook Physics, of Department Korea 41566, Daegu E K.Park H. Science of Accelerator Department Korea 30019, Sejong J.Kim H. SeJin RaSeJin Lee,Kim, H. M. W. Kang, G. D.Leonard, (IBS), Science UndergroundBasic for for Center Institute Physics, 34 Daejeon Scintillation crystal at the CUP growth

PoS(ICHEP2018)668

. s s.

. Mo s meet in the in

pulling ye of type Sejin Ra Sejin

and s using is using NaI:Tl NaI:Tl using

installed based crystal , we have to being grown. being

s 3 are generated during the during generated materials and grown and materials re rdociiy and (radioactivity free in in - OIE is COSINE a a strong of candidate dark air circulation system with system circulation air a and growers Czochralski ies ies background of the crystal the of background vapors

- LMOcrystal experiment the n n an an a

NaI:Tl NaI:Tl growing facility because size size : : purit crystal weight for an automatic an for weight crystal rnal -

(b) two two e im

, the the rwh odto fr each for condition growth e full (b) and for and NaI:Tl MoO the the ventillation system ventillation

low inte low for for th a a -

show s yropoulos growers to grow NaI:Tl crystal NaI:Tl grow to growers yropoulos experiments to measur to

K purified powders.

is controlled by controlled is

s 2 used two considered for

major growth condition such as rotation speedrotation as condition such growth double beta decay search (a characterization of the of characterization (a search decay beta double is

are (a) and (b) and (a)

. the show

Czochralski growers were installed to grow crystals for crystals grow to installed were growers Czochralski

ae Rr poes xeiet (AMoRE) Experiment process Rare based - e e ness ze using highly

li metal) and Tl (toxic to human) to (toxic Tl and metal) s

dust collector and and collector dust siz

based crystal based -

scintillation crystal

to a a

e ing facilities in the CUP the in facilities ing s full ve Mo (a) and (b) and (a)

for neutrinoless for grow efrig et t optimize to tests performing Czochralski growers for Mo crystals forbased Mo growers Czochralski

ls 1,0 evrnet o contamination for environment 10,000 class

Two crystal Weakly Interacting Massive Particle (WIMP, n . a a size resolution load cell’ load resolution - - crystal growthcrystal

growing . Fig. 2 Fig. .

safety and clean or or a h Avne Mo Advanced the crystal f In us order to full D grower to optimi to grower D igh h & ning growing ae bee have and and Two R Mo.

severe severe such as scintillation light yield and ultra and yield light scintillation as such

for (a) 100

an an

s : 1

is is crystal crystal being grown grower a in

process. Due process. this to device, the diameter of the can crystal maintained be by controlling Introduction 4

and plan

Crystalgrowing facilities

to remove NaI (corrosi NaI remove to e report on report e .

s s personal safety personal

herefore, (a) o NIT cytl growth, crystal NaI:Tl For The facility for facility The We have We two independant growing crystal facilities W The CUP is currently conducting two two conducting currently is CUP The ing Figure Figure Growers t ,

MoO e 2

Fig. 2 (a) 2 Fig. Li facility growth. More the of EA itr t keep to filters HEPA growth crystal impurity) ‘ A AMoRE. the grow 1 Fig. growth. the during temperature the 2.1 crystal 2. neutrino) ofneutrino) requirement W crystal scintillating crystal search matter) crystals scintillating based Scintillation crystal growthCUP crystal the at Scintillation 1. PoS(ICHEP2018)668

and th a 0.136 Sejin Ra Sejin (99.999 %,

MS. Table 1Table MS. - growers have (99.95 %, Alfa

have resistance have 3

. s size size ) to grow a crystal growa to ) - (c)

f h impurities the of mm

s grower

was measured to be be to measured was 150 impurities of NaI:Tl crystal NaI:Tl of impurities H

Both (c) origin

´ could could be grown successfully for

e

of Tl was mixed as a dopant anddopant a as mixed wasof Tl

of differenttwo % mm

mm

(99.99 %, Merck) and Tl

150 kg. 150 but other other but , Alfa Aesar) and MoO Tl doped NaI crystal NaI doped Tl trac to 50

a a 120 %

of of er

,

H

8 s Æ ies ´ (

low

(a)(b) grade NaI

- s

mm

(99.99 3

3 80

t t corrosion. Both

CO becomes Æ 2 H 70 mm. In order to confirm the effectiveness of the of effectiveness the confirm to order In mm. 70 H s grower s

NaI:Tl crystal NaI:Tl the growth condition difference.the

´ Sr

powder. It means that there was an external contamination

e quartz crucible quartz or or Li a a

to preven size

(b) -

he amount of Tl in the NaI: Tl crystal crystal NaI:Tl the in of Tl amount he 50 mm 50

full

T e a uniform Tl concentration, the crystal has larger diameter than diameter larger has crystal the concentration, Tl uniform a e o Kyropoulo o dimension of show that that show Æ a a for the test growing. Only 0.1 mol0.1 Onlygrowing. test the for Tw H 100 mm. Alumina refractories were stacked and covered the crucible. re mixed1:1. evenly of Mixed molar ratio with powders charged were

: ´ 2 (c). 2 2

we . NaI:Tl crystal, commercial

used

w grower for for grower 95 %, Alfa Aesar) in the growingin u t a ergto fet uigte rwh Fo ti rsl, vn lower even result, this From growth. the during effect segregation a to due

a a Figure Figure

s MS results results MS . were 100 mm -

is

(99.

3 Æ raw powders weight contamination factors.

Growncrystalsand measurementsofimpurities and covered by refractories

The ICP The

s . aw material A NaI:Tl crystal with CMO LMO and crystals for the AMoRE were grown successfully. We could grow LMO an In order to gro A CaCO Fig. 2 (b) 2 Fig. R COSINE. In order to mak to order In COSINE. same structure internal to minimiz

(a)

creased compared to those of the raw measure the the Fig in shown as height mol% in stud further need we and growth crystal the during crystal with a dimension of dimension a with crystal ICP using measured were samples the all growth, crystal the in removal impurity crystal LMO of Impurities crystal. LMO and powder purified powders, raw in impurities shows reduced be could impurities are expected in a grown crystal with purified powder. 3. the raw powders werepowders charged raw the into 1.7 kgof Aesar) as as Aesar) wi platium one a LMOand in iridium an crucible grownwasin CMOcrucible. crystal a into dimension of Sigma Aldrich) the the 2.2 Scintillation crystal growthCUP crystal the at Scintillation rate. heater PoS(ICHEP2018)668

, , , -

the

6 6

)

-

b U 414 8.0 0.00 0.00 crystals Sejin Ra Sejin 0.85 could e

after (pp 0. 4 < 0.008 < < < W MoO

2

4 6 6

Mo. Mo. )

pure pure scintillation b - 100 Th 0.01 0.00 0.00 0.15

(pp < 0.02 < measured using ICPusing measured < < 0.008 < < < and and Li

of of The European Physical Physical European The 317.3 (2018):1329 317.3 4

, impurity levels

ea Sac Experiment Search Decay Nuclear Science Symposium Symposium Science Nuclear

1700. were ,

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. .

)

9 7 ered b .1 . . νββ using purified powders in near Pb 0 23 99.9 54.5 39 42 to to understand the contamination < 0.1 < (pp

low ies CUP to grow ultra at the CUP the at

0 experiment 100 um iodide (NaI) powder by powder (NaI) iodide um at -

. IEEE, 2012 IEEE, .

shows )

.8 b 9 1 . . grown to be grown

Ba 7.3 2 4 built s 3113

(pp 133 214.2 314.3 (2017): 1695 (2017): 314.3

is

crystal crystal

4 crystal 4 2012 IEEE 2012

s and the raw materials raw the and s

need further stud ) expected

b .0 8 MoO .4 . is 2 Sr NaI:Tl 6 2 we

26.3 19

Kyropoulos method, and CaMoO (pp 1,670 < 0.05 < etioes obe ea decay beta double neutrinoless a a and

and and growing facility . The Li . The

- using LMO )

.6 grown crystal grown

s b however,

- - - K

and and 566 248

better crystal (pp 365 s

Journal of Radioanalytical and Nuclear Chemistry Nuclear and Radioanalytical of Journal . WIMP Technical Design Report for the AMoRE AMoRE the for Report Design Technical nta promne f h COSINE the of performance Initial even Investigation of the molybdenum oxide purification for the AMoRE experiment AMoRE the for purification oxide molybdenum the of Investigation

, , (2015). , , powder

n

) of

A study of CaMoO4 crystals for the experiment AMoRE s with each other

3

, , CUP

3 78.2 (2018): 107. (2018): 78.2 3 result

environment crystal erhs of searches - grow NaI:Tl crystal

CO 2 NaI MS -

impurity levels of the the of levels impurity crystal( MoO case case of NaI:Tl crystal, Li Sample

compared Summary ICP In

a a : Purified MoO Purified Alenkov, V. et al., al., et V. Alenkov,

The The A clean

1332. Shin, KeonAh, et al., Reduction of the radioactivity in sodi in radioactivity the of Reduction al., et KeonAh, Shin, method, recrystallization and Medical Imaging Conference (NSS/MIC), Imaging Medical and al. et Olga, Gileva, Chemistry and Nuclear Radioanalytical of Journal Journal C Journal arXiV:1512.05957 H., So, et J. al. diai G, t al. et G., Adhikari, and and

LMO crystal (CUP) LMOcrystal

NaI:Tl

[5] [4] [2] [3] [1] able 1 able during the growing process howand to reduce them effectively. References using MS growing process and a future. 4. for crystals successfully

T Scintillation crystal growthCUP crystal the at Scintillation