first total absorption spectrometry measurement of the β ...decay heat beta and gamma energy...

Aleksandra FijałkowskaFaculty of Physics, University of Warsaw

M. Karny, K.P. Rykaczewski, M. Wolińska-Cichocka, B.C. Rasco,R. Grzywacz, C.J. Gross, J.W. Johnson, D. Miller, E.F. Zganjar,R. Goans, K.C. Goetz, J.H. Hamilton, C. Jost, M. Madurga,K. Miernik, S.W. Padgett, S.V. Paulauskas, A.V. Ramayya, D. Stracener

06.06.2014 ARIS, Tokyo

First total absorption spectrometry measurement of the β-decay of Xe139

Decay heat

Beta and gamma energy released by the decay of fission products

Ei - mean decay energy

of nucleus i ( β and γ)

λi - decay constant

Ni(t) - number of nuclei i at time t

A. Algora et al., PRL 105, 202501 (2010)A. Tobias, CEGB Report No. RD/B/6210/R89, 1989

Gamma component of 239Pu decay heat

Decay heat

Beta and gamma energy released by the decay of fission products

Ei - mean decay energy

of nucleus i ( β and γ)

λi - decay constant

Ni(t) - number of nuclei i at time t

Radionuclides recommended for TAGS measurementsAssessment offission product, decay data for decay heat calculations, T. Yoshida, A.L. Nichols, OECD NEA, 2007+ Neutron-induced Cummulative Fission Yields (235U)

86 Br 1.6 %87 Br88 Br89 Kr 4.5 %90 Kr98 Nb99 Nb100 Nb

101 Nb 103 Mo105 Mo 102 Tc 103 Tc104 Tc 105 Tc 106 Tc

132 Sb136 I137 I137 Xe139 Xe 5.0 %140 Xe

} B. C. Rasco, β-γ and β-n-γ Emission in Mass A=137 Decay ChainStudied with the Modular Total Absorption Spectrometer (MTAS)

Iiβ

Iiγ in

Iiγ 0ut

i

High efficiency total absorption

γ-spectroscopy

High energy resolution γ-spectroscopy

Parent nucleus

Daughter nucleus

Pandemonium EfectJ. C. Hardy et al., Physics Letter B 71 (1977) 307-310

Compete β-feeding pattern

High efficiency spectrometry

Eγ≈ Ei .Iiβ Σ

Gamma and beta average energy per decay

Beta strength function

Total Absorption Spectrometry, Co spectrum

Source

5+ 0.0 1925.28 d

%B– =100

62

07Co33

Q–=2823.95

0+ 0.0

2+ 1332.50814.702u0.12

2+ 2158.61≥14.02u0.000

4+ 2505.7487.51299.88

L og ftI β–

1332

.492

E2

99.9

826

826.

10 D

+Q

0.00

76

2158

.57

0.00

12

347.

14

0.00

75

1173

.228

E2(

+M3)

99

.85

2505

.692

E4

0.00

0002

0

62

08N i32

1172 keV1332 keV

2505 keV

10

100

1000

10000

100000

500 1000 1500 2000 2500

Counts

per

10 k

eV

Energy [keV]

60

Modular Total Absorption Spectrometer (MTAS)

Carbon fiber

Silicon putty

NaI

Teflon

Steel19 hexagonal NaI crystals. Diameter: 8” length: 21” each.

Simulated full energy gamma ray efficiency for Central detector, Inner ring, and all MTASfor complete MTAS array.

M. Wolińska-Cichocka, Testing the on-line response of Modular TotalAbsorption Spectrometer: 142Ba → 142La → 142Ce decay chain, ARIS2014

January 2012Holifield Radioactive Ion Beam Facility

Experiment

MTASGe

Mass separatorM/ΔM~600

Tandem40Mev

Proton beam

Ion source

238

UCx

Fission product

Two 1 mm thick silicon strip detectors placed around the tape transporting collected activity.

Measurement cycle:1. Sample impantation2. Waiting3. Activity transportation4. Measurement5. Second transportation

Br86

1

10

100

1000

10000

0 1000 2000 3000 4000 5000 6000 7000 8000

Counts

per

keV

Energy [keV]

7.6

MeV

86Br

(2– ) 0.0 55.0 s

%B– =100

83

65Br51

Q– (g.s.)=762611

0+ 0.09.71u15

2+ 1564.617.110

2+ 2349.787.34.9

(2,3)+ 2850.467.33.1

(2)+ 2926.327.22.8

3– 3098.987.14.8

3334.29.21.2

(3– ) 4316.165.451

(1,2) 5406.86.12.9

(1– ,2– ) 5518.85.82.7

(1,2) 6161.76.70.07

(1,2) 6210.15.02.1

(1,2) 67226.2≈0.05

(1,2) 6768.65.70.10

L og ftI β–

1564

.64

65

785.

17

4.5

2349

.6

9.8

499.

2 1.

2

1285

.89

7.5

1361

.68

10.3

2926

.1

2.5

749.

5 0.

72

1534

.7

10.4

1769

.6

1.2

1217

.24

6.0

1389

.79

10.1

1465

.2

5.7

1966

.4

7.5

2751

.3

225406

.5

4.4

5518

.6

2.7

6161

.5

0.07

803.

3 2.

9

6210

.4

0.65

6722

≈0.0

46

6768

.3

0.10

83

66K r50

Peaks in MTAS spectrum correspond to the levels being fed, NOT to the individual gamma transitions.

10%51%

6%14 levels22 gamma transitions

Decay scheme modification

Assumptions:1. Decay scheme is completed up to Ecut energy2. Above Ecut pseudo-levels every 100 keV, up to Qβ

3. Only allowed Gamow-Teller transitions (level density formula - A. Gilbert, A. G. W. Cameron, Can. Jurn. of Phys. 43 (1965))4. Pseudo-levels deexcite to "known" levels.5. Only E1, M1 and E2 transitions

Ecut

(2– ) 0.0 55.0 s

%B– =100

83

65Br51

Q– (g.s.)=762611

0+ 0.09.71u15

2+ 1564.617.110

2+ 2349.787.34.9

(2,3)+ 2850.467.33.1

(2)+ 2926.327.22.8

3– 3098.987.14.8

3334.29.21.2

(3– ) 4316.165.451

(1,2) 5406.86.12.9

(1– ,2– ) 5518.85.82.7

(1,2) 6161.76.70.07

(1,2) 6210.15.02.1

(1,2) 67226.2≈0.05

(1,2) 6768.65.70.10

L og ftI β–

1564

.64

65

785.

17

4.5

2349

.6

9.8

499.

2 1.

2

1285

.89

7.5

1361

.68

10.3

2926

.1

2.5

749.

5 0.

72

1534

.7

10.4

1769

.6

1.2

1217

.24

6.0

1389

.79

10.1

1465

.2

5.7

1966

.4

7.5

2751

.3

225406

.5

4.4

5518

.6

2.7

6161

.5

0.07

803.

3 2.

9

6210

.4

0.65

6722

≈0.0

46

6768

.3

0.10

83

66K r50

Qβ

Br86

average gamma energy increasedfrom 3259 keV to 3712 keV (14%)

Counts

per

10 k

eV

1

10

100

1000

10000

0 1000 2000 3000 4000 5000 6000 7000 8000

Energy [keV]

7.6

Me

V

86Br

Ecu

t

20

40

60

80

100

0 1000 2000 3000 4000 5000 6000 7000 8000

Cum

ula

ive f

eedin

g (

%)

Energy [keV]

Q =

7.6

3 M

eV

86Br

Br, gamma spectrum86C

ounts

per

10 k

eV

1

10

100

1000

10000

0 1000 2000 3000 4000 5000 6000 7000 8000

Energy [keV]7.6

MeV

86Br

Xe139

63 levels263 gamma transitions

1CI TAT I ON :N uclear Data Sheets (2001)

F rom N N DC(BN L )program E N SDAT

135

95Cs84

135

95Cs84

139Xe ββββ– Decay 1988Fa06,1980L e03,1972Ac02

3/2– 0.0 39.68 s

%B– =100

135

94Xe85

Q–=505721

7/2+ 0.08.61u16

5/2+,7/2+ 218.6447.34.9

3/2+,5/2,7/2+ 289.767.61.9

5/2(+),7/2+ 393.486.713.8

3/2,5/2,7/2+ 393.797.61.6

3/2(+),5/2(+) 515.226.421.94450

3/2,5/2,7/2+ 646.528.20.334380

3/2+,5/2,7/2+ 732.387.42.2

3/2,5/2,7/2+ 891.587.61.1

3/2,5/2,7/2+ 942.547.51.18

1/2,3/2,5/2 1006.736.68.8

3/2,5/2,7/2+ 1020.307.51.16

3/2,5/2,7/2+ 1215.028.10.22

1395.257.90.34

1461.317.40.86

1599.997.70.38

1652.757.01.7

1693.927.70.35

1738.697.11.29

1793.2

1831.47.60.32

2099.627.60.27

3/2,5/2,7/2+ 2103.8

2119.647.20.6

1/2,3/2,5/2 2372.957.00.71

3/2,5/2,7/2+ 2423.5≥7.5≤0.20

1/2,3/2,5/2 2586.066.70.98

2727.637.30.20

1/2,3/2,5/2 2967.466.50.81

1/2,3/2,5/2 2980.457.20.15

3/2,5/2 3130.337.00.16

3/2,5/2 3146.77.30.09

3/2,5/2 3156.087.10.14

1/2,3/2,5/2 3208.836.60.40

1/2,3/2,5/2 3372.736.90.14

3/2,5/2 3375.406.40.41

3/2,5/2 3504.676.30.38

1/2,3/2,5/2 3745.56.00.40

1/2,3/2,5/2 3776.006.20.21

1/2,3/2,5/2 3815.236.50.10

1/2,3/2,5/2 3924.746.10.16

1/2– ,3/2– ,5/2– 4227.675.90.10

L og ftI β–E β–

Decay Scheme

I ntensi ties: I (γ+ce) per 100 parent decays

@ M ul tiply placed; intensi ty sui tably divided

& M ul tiply placed; undivided intensi ty given

1149

.2

0.14

0

1765

.2

0.05

0

2761

.6

0.06

7

2736

.7 &

0.

12

2736

.7 &

0.

12

2911

.7

0.06

7

3130

.6

0.08

2255

.3

0.09

0

3146

.6

0.06

2

783.

1 0.

062

1036

.3

0.12

3

3156

.3

0.04

5

1608

.7

0.09

5

2693

.4

0.07

8

2815

.03

0.22

1273

.1

0.04

5

1911

.42

0.11

8

2430

.3

0.03

9

2640

.1

0.03

4

1543

.6

0.02

8

1681

.1

0.19

1722

.6

0.10

6

3375

.51

0.15

1

1711

.44

0.28

1851

.8

0.09

5

2613

.7

0.03

4

2989

.4

0.07

3

3110

.8 &

0.

039

3110

.8 &

0.

039

3214

.8

0.03

9

3504

.7

0.06

71017

.7

0.09

0

1641

.7

0.15

7

2006

.8

0.11

2

2854

.2

0.09

0

1351

.6

0.09

5

2769

.32

0.30

2872

.65

0.12

3

3168

.7

0.06

2

957.

3 0.

067

2903

.8

0.07

8

2918

.3

0.12

1803

.99

0.11

2

2832

.8

0.06

2

135

95Cs84



135

95Cs84

135

95Cs84

139Xe ββββ– Decay 1988Fa06,1980L e03,1972Ac02 (continued)

3/2– 0.0 39.68 s

%B– =100

135

94Xe85

Q–=505721

7/2+ 0.08.61u16

5/2+,7/2+ 218.6447.34.9

3/2+,5/2,7/2+ 289.767.61.9

5/2(+),7/2+ 393.486.713.8

3/2,5/2,7/2+ 393.797.61.6

3/2(+),5/2(+) 515.226.421.94450

3/2,5/2,7/2+ 646.528.20.334380

3/2+,5/2,7/2+ 732.387.42.2

3/2,5/2,7/2+ 891.587.61.1

3/2,5/2,7/2+ 942.547.51.18

1/2,3/2,5/2 1006.736.68.8

3/2,5/2,7/2+ 1020.307.51.16

1139.11

1395.257.90.34

1508.247.90.24

1599.997.70.38

1652.757.01.7

1693.927.70.35

1738.697.11.29

3/2,5/2,7/2+ 1816.5≥8.0≤0.15

3/2,5/2,7/2+ 2063.607.20.6

1/2,3/2,5/2 2185.586.52.1

3/2,5/2 2304.716.43.0

1/2,3/2,5/2 2586.066.70.98

1/2,3/2,5/2 2620.606.80.79

2727.637.30.20

3/2,5/2 2754.136.90.45

1/2,3/2,5/2 2797.556.51.10

1/2,3/2,5/2 2852.317.20.18

3/2,5/2 2936.847.00.24

1/2,3/2,5/2 2967.466.50.81

3/2,5/2 3130.337.00.16

1/2,3/2,5/2 3208.836.60.40

1/2,3/2,5/2 3372.736.90.14

3/2,5/2 3504.676.30.38

1/2,3/2,5/2 3745.56.00.40

1/2,3/2,5/2 3924.746.10.16

1/2– ,3/2– ,5/2– 4227.675.90.10


Decay Scheme (continued)




847.

45

0.26

1190

.6

0.08

1579

.5

0.20

1939

.5

0.09

5

2192

.32

0.34

2366

.97

0.13

4

926.

8 0.

034

967.

3 0.

067

1022

.0

0.03

9

1481

.5

0.06

7

1613

.8

0.26

2227

.28

0.37

1219

.33

0.19

2437

.8

0.09

5

937.

9 0.

067

1615

.0

0.16

1862

.4

0.07

3

2021

.8

0.10

1

2238

.4

0.15

2464

.6

0.11

2

2535

.0

0.06

2

2754

.2

0.06

7

1776

.9

0.18

5

1790

.85

0.43

1854

.5

0.13

2403

.75

0.26

2507

.6

0.07

8

2578

.9

0.06

2

1199

.43

0.18

2633

.75

0.10

6

1428

.70

0.18

5

2936

.2

0.05

6

1228

.8

0.07

8

1458

.98

0.25

1830

.2 @

0.

078

2025

.1

0.05

6

2451

.6

0.04

5

2574

.04

0.34

135

95Cs84



135

95Cs84

135

95Cs84


3/2– 0.0 39.68 s

%B– =100

135

94Xe85

Q–=505721

7/2+ 0.08.61u16

5/2+,7/2+ 218.6447.34.9

3/2+,5/2,7/2+ 289.767.61.9

5/2(+),7/2+ 393.486.713.8

3/2,5/2,7/2+ 393.797.61.6

3/2(+),5/2(+) 515.226.421.94450

3/2,5/2,7/2+ 646.528.20.334380

3/2+,5/2,7/2+ 732.387.42.2

3/2,5/2,7/2+ 891.587.61.1

3/2,5/2,7/2+ 942.547.51.18

1/2,3/2,5/2 1006.736.68.8

3/2,5/2,7/2+ 1020.307.51.16

1037.278.20.23

1139.11

3/2,5/2,7/2+ 1215.028.10.22

1395.257.90.34

1508.247.90.24

1599.997.70.38

1652.757.01.7

1738.697.11.29

1831.47.60.32

1/2,3/2,5/2 2185.586.52.1

3/2,5/2 2304.716.43.0

3/2,5/2 2328.776.42.7

1/2,3/2,5/2 2372.957.00.71

3/2,5/2,7/2+ 2423.5≥7.5≤0.20

2432.447.30.31

3/2,5/2 2510.466.51.84

2727.637.30.20

1/2,3/2,5/2 2852.317.20.18

3/2,5/2 2936.847.00.24

3/2,5/2 3130.337.00.16

1/2,3/2,5/2 3208.836.60.40

1/2,3/2,5/2 3372.736.90.14

3/2,5/2 3504.676.30.38

1/2,3/2,5/2 3745.56.00.40

1/2,3/2,5/2 3924.746.10.16

1/2– ,3/2– ,5/2– 4227.675.90.10






119.

4 1.

5

1297

.85

0.44

2015

.11

0.17

4

2085

.91

0.63

2304

.97

0.29

589.

8 0.

084

675.

79

0.16

2

820.

5 0.

078

1115

.0 &

0.

17

1291

.4

0.17

1309

.4

0.33

1386

.19

0.52

1814

.1

0.12

3

1935

.1 &

0.

112

1935

.1 &

0.

112

2039

.1

0.07

8

2110

.12

0.34

2328

.80

0.63

634.

2 0.

034

719.

8 0.

07

1233

.8

0.03

9

1857

.6

0.11

2

1979

.57

0.52

1416

.94

0.16

2204

.6

0.04

5

2423

.6

0.04

5

832.

41

0.07

3

1540

.1

0.06

2

1700

.2

0.16

1786

.6

0.06

2

772.

0 0.

056

1490

.0

0.21

1503

.1

0.20

2

1862

.4

0.30

1994

.2

0.08

4

2116

.88

0.32

2291

.61

0.40

2510

.41

0.27

135

95Cs84



135

95Cs84

135

95Cs84


3/2– 0.0 39.68 s

%B– =100

135

94Xe85

Q–=505721

7/2+ 0.08.61u16

5/2+,7/2+ 218.6447.34.9

3/2+,5/2,7/2+ 289.767.61.9

5/2(+),7/2+ 393.486.713.8

3/2,5/2,7/2+ 393.797.61.6

3/2(+),5/2(+) 515.226.421.94450

595.43≥8.2≤0.37

3/2,5/2,7/2+ 646.528.20.334380

3/2+,5/2,7/2+ 732.387.42.2

3/2,5/2,7/2+ 942.547.51.18

1/2,3/2,5/2 1006.736.68.8

3/2,5/2,7/2+ 1020.307.51.16

1139.11

3/2,5/2,7/2+ 1215.028.10.22

1411.7≥8.3≤0.11

1599.997.70.38

1693.927.70.35

1718.437.50.57

1721.94

1738.697.11.29

1793.2

3/2,5/2,7/2+ 1816.5≥8.0≤0.15

1831.47.60.32

3/2,5/2,7/2+ 2063.607.20.6

2099.627.60.27

3/2,5/2,7/2+ 2103.8

2119.647.20.6

1/2,3/2,5/2 2185.586.52.1

1/2,3/2,5/2 2372.957.00.71

3/2,5/2 2510.466.51.84

1/2,3/2,5/2 2586.066.70.98

2727.637.30.20

1/2,3/2,5/2 2852.317.20.18

3/2,5/2 2936.847.00.24

3/2,5/2 3130.337.00.16

1/2,3/2,5/2 3208.836.60.40

1/2,3/2,5/2 3372.736.90.14

3/2,5/2 3504.676.30.38

1/2,3/2,5/2 3745.56.00.40

1/2,3/2,5/2 3924.746.10.16

1/2– ,3/2– ,5/2– 4227.675.90.10






960.

6 0.

056

1178

.73

@

0.34

1299

.8

0.05

0

1404

.16

0.12

9

579.

4 0.

056

986.

02

0.30

1324

.38

0.21

1126

.5

1344

.93

@

1.01

1344

.93

@

0.10

1

1449

.0

0.14

0

1520

.17

0.71

786.

7 0.

022

1793

.0

0.06

2

1817

.6

0.15

1

888.

6 0.

067

1316

.4

0.15

1

1437

.7

0.11

1612

.4

0.15

924.

5 0.

162

1416

.5

0.17

4

1773

.84

0.30

2063

.7

0.39

1367

.19

0.16

8

1584

.7

0.12

2103

.7

0.05

6

55.7

D(+

Q)

0.6

980.

59

0.12

3

1099

.4

0.06

2

446.

8 0.

101

585.

6 0.

045

773.

4 0.

112

970.

3 0.

084

1046

.31

0.30

1178

.73

@

0.02

8

1242

.88

0.65

1453

.32

0.49

1670

.33

1.10

1895

.98

0.60

1967

.3

0.12

3

135

95Cs84



135

95Cs84

135

95Cs84


3/2– 0.0 39.68 s

%B– =100

135

94Xe85

Q–=505721

7/2+ 0.08.61u16

5/2+,7/2+ 218.6447.34.9

3/2+,5/2,7/2+ 289.767.61.9

5/2(+),7/2+ 393.486.713.8

3/2,5/2,7/2+ 393.797.61.6

3/2(+),5/2(+) 515.226.421.94450

595.43≥8.2≤0.37

3/2,5/2,7/2+ 646.528.20.334380

710.298.70.11

3/2+,5/2,7/2+ 732.387.42.2

3/2,5/2,7/2+ 891.587.61.1

3/2,5/2,7/2+ 942.547.51.18

1/2,3/2,5/2 1006.736.68.8

3/2,5/2,7/2+ 1020.307.51.16

1037.278.20.23

1139.11

3/2,5/2,7/2+ 1215.028.10.22

1395.257.90.34

1411.7≥8.3≤0.11

1461.317.40.86

1508.247.90.24

1510.33

1599.997.70.38

1652.757.01.7

1831.47.60.32

3/2,5/2,7/2+ 2063.607.20.6

1/2,3/2,5/2 2185.586.52.1

3/2,5/2 2304.716.43.0

3/2,5/2,7/2+ 2423.5≥7.5≤0.20

3/2,5/2 2510.466.51.84

1/2,3/2,5/2 2586.066.70.98

2727.637.30.20

1/2,3/2,5/2 2852.317.20.18

3/2,5/2 2936.847.00.24

3/2,5/2 3130.337.00.16

1/2,3/2,5/2 3208.836.60.40

1/2,3/2,5/2 3372.736.90.14

3/2,5/2 3504.676.30.38

1/2,3/2,5/2 3745.56.00.40

1/2,3/2,5/2 3924.746.10.16

1/2– ,3/2– ,5/2– 4227.675.90.10






505.

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1362

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0.31

1434

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0.25

1652

.8

0.11

135

95Cs84



135

95Cs84

135

95Cs84


3/2– 0.0 39.68 s

%B– =100

135

94Xe85

Q–=505721

7/2+ 0.08.61u16

5/2+,7/2+ 218.6447.34.9

3/2+,5/2,7/2+ 289.767.61.9

5/2(+),7/2+ 393.486.713.8

3/2,5/2,7/2+ 393.797.61.6

3/2(+),5/2(+) 515.226.421.94450

595.43≥8.2≤0.37

3/2,5/2,7/2+ 646.528.20.334380

710.298.70.11

3/2+,5/2,7/2+ 732.387.42.2

3/2,5/2,7/2+ 891.587.61.1

3/2,5/2,7/2+ 942.547.51.18

1/2,3/2,5/2 1006.736.68.8

1139.11

3/2,5/2,7/2+ 1215.028.10.22

1395.257.90.34

1508.247.90.24

1599.997.70.38

1693.927.70.35

1793.2

3/2,5/2,7/2+ 2063.607.20.6

1/2,3/2,5/2 2185.586.52.1

3/2,5/2 2304.716.43.0

3/2,5/2,7/2+ 2423.5≥7.5≤0.20

3/2,5/2 2510.466.51.84

1/2,3/2,5/2 2586.066.70.98

2727.637.30.20

1/2,3/2,5/2 2852.317.20.18

3/2,5/2 2936.847.00.24

3/2,5/2 3130.337.00.16

1/2,3/2,5/2 3208.836.60.40

1/2,3/2,5/2 3372.736.90.14

3/2,5/2 3504.676.30.38

1/2,3/2,5/2 3745.56.00.40

1/2,3/2,5/2 3924.746.10.16

1/2– ,3/2– ,5/2– 4227.675.90.10






218.

59 E

2+M

1 63

71.0

[M

1,E2]

1.

1

289.

78 (

E2)

9.

6

103.

75 (

M1+

E2)

0.

64

174.

97 @

D(+

Q)

12.8

393.

50 (

M1+

E2)

6.

9

174.

97 @

D(+

Q)

9.8

121.

37 @

0.

47

121.

37 @

0.

062

225.

38 [

M1,

E2]

3.

3

296.

53 (

M1,

E2)

22

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515.

44 [

M1,

E2]

0.

37

595.

43

0.28

356.

72 n

otM

1 0.

57

646.

50

0.62

491.

47 @

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34

338.

86 D

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0.63

442.

7 [D

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0.

181

513.

88 [

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732.

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1.91

181.

3 0.

140

498.

2 [D

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0.

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601.

84

1.2

672.

39

0.14

6

891.

76

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4

427.

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0.

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062

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02 @

0.

69

652.

5 0.

27

723.

84

1.80

942.

61

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491.

47 @

1.

46

612.

82 @

4.

5

612.

82 @

1.

23

716.

96

0.16

2

788.

04

3.5

135

95Cs84

1

10

100

1000

10000

0 1000 2000 3000 4000 5000

Energy [keV]

5.0

6 M

eV

139Xe

Cou

nts

per

10

keV

Xe139

63 levels263 gamma transitionsaverage gamma energy increasedfrom 935 keV to 1370 keV (43%)

20

40

60

80

100

0 1000 2000 3000 4000 5000

Cum

ula

ive f

eedin

g (

%)

Energy [keV]

5.0

6 M

eV

139Xe

1

10

100

1000

10000

0 1000 2000 3000 4000 5000

Energy [keV]5.0

6 M

eV

139Xe

Ecu

t

Counts

per

10 k

eV

Anti-neutrino spectrum

A. Strumia, F. Vissani, PLB 564 (2003)

0

0.002

0.004

0.006

0.008

0.01

0 1000 2000 3000 4000 5000 6000

Energy [keV]

Number of 139Xe anti-neutrino interactions with protons(Antineutrino energy distribution

multiplied by inverse beta decay cross section)

0

0.05

0.1

0.15

0.2

0.25

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 1000 2000 3000 4000 5000 6000

Neutr

ino p

robabili

ty in

% p

er

10 k

eV

Energy [keV]

σ (

ν̄ep

→ne

+)in 1

0−

41 c

m2

139Xe

Σ = 1.49 10−41 cm2

Σ = 1.87 10−41 cm2

20% difference

Deduced anti-neutrino spectrum

ENSDF

MTAS

Summary

Twenty-two decays of fission product, including seven of the first priority list established by the OECD NEA assessment in 2007 were measured with MTAS

Experimental spectrum shows excess of high-energy gamma-transitions not present in the ENSDF data base

MTAS measurements led to different beta decay patterns, resulting in a decrease of average energy of emitted beta and anti-neutrino particles and in an increase in average gamma energy (increase of “decay heat”)

Analysis changed the knowledge about average gamma energy per decay:

Xe139 935 keV 1370 keV 43%Br86 3259 keV 3712 keV 14%

Kr89 1801 keV 2647 keV 47%M. Karny First results from the Modular Total AbsorptionSpectrometer (MTAS) at the HRIBF (ORNL, Oak Ridge), ARIS 2014

Co60

1

10

100

1000

10000

100000

500 1000 1500 2000 2500

Counts

per

10 k

eV

Energy [keV]

1

10

100

1000

10000

100000

500 1000 1500 2000 2500

Co

un

ts p

er

10

ke

VEnergy [keV]

B. C. Rascoβ-γ and β-n-γ Emission in Mass A=137 Decay Chain Studied with the Modular Total Absorption Spectrometer (MTAS)

127XI and 23Na Neutron Capture Peak

137I

first total absorption spectrometry measurement of the β ...decay heat beta and gamma energy...

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