Cosmogenic  Ac,va,on  Evalua,on      

 Chao  Zhang  and  Dongming  Mei  University  of  South  Dakota  

Ac,va,on  at  sea  level  

•  Targets  are  concerned  •  Produc<on  rate  •  Exposure  <me  •  Materials  at  risk  •  Shielding  and  protec<on        

Targets  are  concerned    •  Xenon  gas  cylinders  on  the  surface  –  Target  for  dark  maBer  searches    

•  Copper  bricks,  rods,  sheets  –  Inner  detector  parts  

•  Ti  vessel    –  Inner  detector  vessel  

•  Stainless  Steel    –  Inner  parts    

•  Teflon  –  Inner  parts    

Cosmogenic  produc,on  is  only  relevant  to  the  inner  parts  due  to    a  rela,ve  low  ac,vity  comparing  to  natural  radioac,vity    

Geometry  

•  Xenon  gas  cylinder  – Stainless  steel:  12”D  *  50”H  with  0.3”  in  thickness  – Xenon  gas:  970psi  gauge,  density  0.3657  g/cm3.  temperature  20  oC.  Total  mass  in  the  cylinder:  30kg.  

•  Bulk  volume:  Cu,  Ti,  SSteel  and  Teflon  –  10  cm  in  diameter  and  10  cm  in  height  

4  

Input  Muons  •  Modified  Gaisser’s  formula  is  used  to  sample  muons  right  above  the  gas  cylinder.  Enery  range  spans  from  1GeV  to  50TeV.  Total  flux  normalized  to    0.0137054/cm2/s.    

5  

Input  neutrons  

Ø  Thermal  neutron  flux  adopted  from  simula<on  results  from  MCNPX(Chris  Hagmann,  LLNL,  2012)  with  the  energy  range[1e-­‐8,  4]MeV.  Total  flux  normalized  to  0.002/cm2/s.    

6  

Ø  Fast  neutron  is  taking  measurement  result  “NY  data”  (M.S.Gordon,  2004)  with  energies  [4,  2000]MeV.  Total  flux  normalized  to    0.00405231/cm2/s.      

Produc,on  rate  in  xenon  (kg-­‐1d-­‐1)  

Only  produc,on  of  127Xe  is  a  concern  

P2P networks: Methods and open problems

Hermanni Hyytiala

Agora Center, University of Jyvaskyla P.O. Box 35, FIN-40014 Jyvaskyla Tel.:

+358 14 260 1211

1 Introduction

Table 1

Isotopn(<4MeV) n(>4MeV) µ Total

(activation in Xenon gas, /kg/day) (/kg/day)

31H, 12.3y(β) 0 28.92 0.5921 29.51

8136Kr, 2.3e5y(γ,β, x) 0 0.0461 0 0.0461

10948 Cd, 462.6d(γ,β, x) 0 1.367 0 1.367

11350 Sn, 115.1d(γ,β, x) 0 6.504 0 6.504

11950 Sn, 293.1d(γ, x) 0 1.488 0 1.488

12451 Sb, 60.2d(γ,β, x) 0 1.586 0 1.586

12551 Sb, 2.8y(γ,β, x) 0 1.453 0 1.453

12152 Te, 154d(γ,β, x) 0 20.60 0.09868 20.70

12352 Te, 119.7d(γ,β, x) 0 17.93 0.1974 18.12

12553 I, 59.4d(γ,β, x) 0 76.14 0.3947 76.53

12953 I, 1.57e7y(γ,β, x) 0 76.23 0.2960 76.52

12754 Xe, 36.4d(γ,β, x) 0.6401 228.8 1.48 230.9

13354 Xe, 5.2d(γ,β, x) 11.08 85.58 1.678 98.34

13554 Xe, 9.1h(γ,β, x) 2.175 56.19 1.085 59.45

Email address: hemppah@cc.jyu.fi (Hermanni Hyytiala).1

This work was funded by the Agora Center InBCT project.

Preprint submitted to Elsevier 14 July 2014

GEANT4:  127Xe:    4.6604E-­‐04  Bq/kg                            LUX:  (490+/-­‐90)x10-­‐6  Bq/kg      

Produc,on  rate  in  copper    Table 1

Isotopn(<4MeV) n(>4MeV) µ Total

(activation in Cu, /kg/day) (/kg/day)

2211Na, 2.6y(γ) 0 0.01172 0.002692 0.01442

2613Al, 7.2e5y(γ) 0 0.01641 0.002692 0.0191

3214Si, 150y(β) 0 0.0633 0.002692 0.066

4019K, 1.3e9y(γ) 0 0.4806 0.02154 0.5022

4720Ca, 4.5d(γ) 0 0.1243 0 0.1243

4621Sc, 83.8d(γ) 0 1.048 0.02423 1.072

4721Sc, 3.3d(γ) 0 0.9824 0.01077 0.9931

4422T i, 63y(γ) 0 1.719 0.04846 1.767

5023V , 1.4e17y(γ) 0 3.318 0.02692 3.344

5124Cr, 27.7d(γ) 0 15.2 0.1212 15.32

5425Mn, 312.3d(γ) 0 11.68 0.07539 11.75

5526Fe, 2.7y(γ%) 0 53.66 0.2504 53.91

5926Fe, 44.5d(γ) 0 8.558 0.035 8.593

6026Fe, 1.5e6y(γ) 0 4.905 0.02962 4.934

5627Co, 77.3d(γ) 0 9.709 0.07539 9.784

5727Co, 271.8d(γ) 0 64.33 0.2612 64.6

5827Co, 70.9d(γ) 0 55.52 0.1669 55.68

6027Co, 5.3y(γ) 0.0163 63.12 0.2423 63.38

6530Zn, 244.3d(γ) 0 1.798 0.01885 1.817

Table 2

IsotopNeutron(<4MeV) Neutron(>4MeV) Muon Total

(activation in Teflon, /kg/day) (/kg/day)

74Be, 53.1d(γ) 0 15.8 0.04386 15.85

104 Be, 1.5e6y(β) 0 65.34 0.05483 65.4

146 C, 5.7e3y(β) 0.09009 0.009549 0 0.09964

2

Isotopes  colored    in  red    are  at  a  cau,on    

Produc,on  rate  in  Ti    Table 2

IsotopNeutron(<4MeV) Neutron(>4MeV) Muon Total

(activation in Ti, /kg/day) (/kg/day)

2211Na, 2.6y(γ) 0 0.1958 0 0.1958

2613Al, 7.2e5y(γ) 0 0.4056 0.01606 0.4217

3214Si, 150y(β) 0 1.511 0 1.511

4019K, 1.3e9y(γ) 0 20.98 0.1178 21.1

4720Ca, 4.5d(γ) 0 10.13 0.005354 10.14

4621Sc, 83.8d(γ) 0.3148 270.4 0.4336 271.2

4721Sc, 3.3d(γ) 1.831 385.4 0.5407 387.7

4422T i, 63y(γ) 0 95.94 0.4551 96.4

5023V , 1.4e17y(γ) 0 0.317 0.005354 0.3224

5124Cr, 27.7d(γ) 0 0.02331 0 0.02331

2

Isotopes  colored    in  red  are  at  a  cau,on    

Produc,on  rate  in  stainless  Steel  Isotopes  colored    in  red  are  at  a  cau,on    Table 1

Isotopn(<4MeV) n(>4MeV) µ Total

(activation in SSteel, /kg/day) (/kg/day)

74Be, 53.1d(γ) 0 0.02093 0.006008 0.02694

104 Be, 1.5e6y(β) 0 0.102 0 0.102

146 C, 5.7e3y(β) 0.6028 1.162 0.006008 1.77

2211Na, 2.6y(γ) 0 0.225 0.003004 0.228

2613Al, 7.2e5y(γ) 0 0.8031 0.006008 0.8091

3214Si, 150y(β) 0 0.3244 0.01802 0.3424

4019K, 1.3e9y(γ) 0 2.6 0.03605 2.636

4720Ca, 4.5d(γ) 0 0.9706 0.003004 0.9736

4621Sc, 83.8d(γ) 0 8.429 0.03905 8.468

4721Sc, 3.3d(γ) 0 8.774 0.01502 8.789

4422T i, 63y(γ) 0 12.14 0.1472 12.29

5023V , 1.4e17y(γ) 0.2507 70.58 0.2403 71.08

5124Cr, 27.7d(γ) 3.94 282.5 5.338 291.8

5425Mn, 312.3d(γ) 3.527 222.2 0.6879 226.5

5526Fe, 2.7y(γ%) 3.776 621.8 18.3 643.9

5926Fe, 44.5d(γ) 0.1403 0.3061 0 0.4464

6026Fe, 1.5e6y(γ) 0 0.07848 0 0.07848

5627Co, 77.3d(γ) 0 14.68 0.09914 14.78

5727Co, 271.8d(γ) 0 79.12 0.1472 79.27

5827Co, 70.9d(γ) 8.148 80.07 0.3935 88.61

6027Co, 5.3y(γ) 0.001299 6.166 0.009012 6.176

2

Produc,on  rate  in  Teflon  Isotopes  colored    in  red  are  may  be  at  a  cau,on    

Table 1

Isotopn(<4MeV) n(>4MeV) µ Total

(activation in Cu, /kg/day) (/kg/day)

2211Na, 2.6y(γ) 0 0.01172 0.002692 0.01442

2613Al, 7.2e5y(γ) 0 0.01641 0.002692 0.0191

3214Si, 150y(β) 0 0.0633 0.002692 0.066

4019K, 1.3e9y(γ) 0 0.4806 0.02154 0.5022

4720Ca, 4.5d(γ) 0 0.1243 0 0.1243

4621Sc, 83.8d(γ) 0 1.048 0.02423 1.072

4721Sc, 3.3d(γ) 0 0.9824 0.01077 0.9931

4422T i, 63y(γ) 0 1.719 0.04846 1.767

5023V , 1.4e17y(γ) 0 3.318 0.02692 3.344

5124Cr, 27.7d(γ) 0 15.2 0.1212 15.32

5425Mn, 312.3d(γ) 0 11.68 0.07539 11.75

5526Fe, 2.7y(γ%) 0 53.66 0.2504 53.91

5926Fe, 44.5d(γ) 0 8.558 0.035 8.593

6026Fe, 1.5e6y(γ) 0 4.905 0.02962 4.934

5627Co, 77.3d(γ) 0 9.709 0.07539 9.784

5727Co, 271.8d(γ) 0 64.33 0.2612 64.6

5827Co, 70.9d(γ) 0 55.52 0.1669 55.68

6027Co, 5.3y(γ) 0.0163 63.12 0.2423 63.38

6530Zn, 244.3d(γ) 0 1.798 0.01885 1.817

Table 2

Isotopn(<4MeV) n(>4MeV) µ Total

(activation in Teflon, /kg/day) (/kg/day)

74Be, 53.1d(γ) 0 15.8 0.04386 15.85

104 Be, 1.5e6y(β) 0 65.34 0.05483 65.4

146 C, 5.7e3y(β) 0.09009 0.009549 0 0.09964

2

Comparison  with  ACTIVIA  for  some    isotopes  

Isotopes   Geant4    (Bq/kg)  (USD)  

ACTIVIA  (Bq/kg)  (VK)  

Experiments  (Bq/kg)  (LUX)  

127Xe  (in  Xe)   4.7x10-­‐4     7.2x10-­‐5   (4.9±0.9)x10-­‐4    133Xe  (in  Xe)   7.0x10-­‐9   1.1x10-­‐9   (5.0±0.5)x10-­‐9  

60Co  (in  Cu)   4.6x10-­‐5   4.7x10-­‐5  

46Sc  (In  Ti)   1.2x10-­‐3   4.6x10-­‐4  

57Co  in  (in  SS)   3.4x10-­‐4   4.2x10-­‐4  

Summary  

•  All  isotopes  produced  by  cosmogenic  processes  are  compared  with  ACTIVIA  

•  Exposure  <me  – The  <me  on  the  surface  needs  to  be  minimized.    

•  Materials  at  risk  – Valida<on  of  codes  needs  to  be  performed    

•  Shielding  and  protec<on  – Needs  a  reliable  MC  code  to  design