10.1.3.1. MT Reaction Types on SCALE Cross-Section Libraries

ENDF reaction types (MT) are identified by an integer number from 1 through 999. Table 10.1.17 includes a copy of information taken from Ref. 8. Within SCALE, MT numbers are used to identify reactions on various input and output arrays.

MT numbers greater than 999 are additional SCALE-specific identifiers that may appear in SCALE cross-section libraries. These reaction types are not ENDF reaction types but may be added by various preprocessing codes in the SCALE and/or AMPX systems.

These reactions are listed in Table 10.1.18.

The dose conversion factors and their corresponding MT numbers in the SCALE shielding cross-section libraries can be found in Table 10.1.14.

Table 10.1.17 ENDF MT Reaction Types.

MT

Reaction

Description

1

(n,total)

Neutron total cross sections. Sum of MT=2, 4, 5, 11, 16-18, 22-26, 28-37, 41-42, 44-45, 102-117.

2

(z,z0)

Elastic scattering cross section for incident particles.

3

(z,nonelastic)

Nonelastic neutron cross section. Sum of MT=4, 5, 11, 16-18, 22-26, 28-37, 41-42, 44-45, 102-117.

4

(z,n)

Production of one neutron in the exit channel. Sum of the MT=50-91.

5

(z,anything)

Sum of all reactions not given explicitly in another MT number. This is a partial reaction to be added to obtain MT=1.

6-9

Not allowed in version 6.

10

(z,continuum)

Total continuum reaction; includes all continuum reactions and excludes all discrete reactions.

11

(z,2nd)

Production of two neutrons and a deuteron, plus a residual.

12-15

(Unassigned)

16

(z,2n)

Production of two neutrons and a residual [XS1]. Sum of MT=875-891, if they are present.

17

(z,3n)

18

(z,fission)

19

(n,f)

20

(n,nf)

Second-chance fission [XS2].

21

(n,2nf)

Third-chance fission[XS2].

22

(z,n\(\alpha\))

Production of a neutron and an alpha particle, plus a residual.

23

(n,n3\(\alpha\)

Production of a neutron and three alpha particles, plus a residual.

24

(z,2n\(\alpha\))

Production of two neutrons and an alpha particle, plus a residual.

25

(z,3n\(\alpha\))

Production of three neutrons and an alpha particle, plus a residual.

26

Not allowed in version 6.

27

(n,abs)

Absorption; sum of MT=18 and MT=102 through MT=117.

28

(z,np)

Production of a neutron and a proton, plus a residual.

29

(z,n2\(\alpha\))

Production of a neutron and two alpha particles, plus a residual.

30

(z,2n2\(\alpha\))

Production of two neutrons and two alpha particles, plus a residual.

31

Not allowed for version 6.

32

(z,nd)

Production of a neutron and a deuteron, plus a residual.

33

(z,nt)

Production of a neutron and a triton, plus a residual.

34

(z,n3He)

Production of a neutron and a 3He particle, plus a residual.

35

(z,nd2\(\alpha\))

Production of a neutron, a deuteron, and 2 alpha particles, plus a residual.

36

(z,nt2\(\alpha\))

Production of a neutron, a triton, and 2 alpha particles, plus a residual.

37

(z,4n)

Production of 4 neutrons, plus a residual.

38

(n,3nf)

Fourth-chance fission cross section2.

39

Not allowed for version 6.

40

Not allowed for version 6.

41

(z,2np)

Production of 2 neutrons and a proton, plus a residual.

42

(z,3np)

Production of 3 neutrons and a proton, plus a residual.

43

(Unassigned)

44

(z,n2p)

Production of a neutron and 2 protons, plus a residual.

45

(z,np\(\alpha\))

Production of a neutron, a proton, and an alpha particle, plus a residual.

46-49

Not allowed in Version 6.

50

(y,n0)

Production of a neutron, leaving the residual nucleus in the ground state.

51

(z,n1)

Production of a neutron, with residual in the 1st excited state.

52

(z,n2)

Production of a neutron, with residual in the 2nd excited state.

…

…

90

(z,n40)

Production of a neutron, with residual in the 40th excited state.

91

(z,nc)

Production of a neutron in the continuum not included in the above discrete representation.

92-100

(Unassigned)

101

(n,disap)

Neutron disappearance; equal to sum of MT=102-117.

102

(z,:math:gamma)

Radiative capture.

103

(z,p)

Production of a proton, plus a residual. Sum of MT=600-649, if they are present.

104

(z,d)

Production of a deuteron, plus a residual. Sum of MT=650-699, if they are present.

105

(z,t)

Production of a triton, plus a residual. Sum of MT=700-749, if they are present.

106

(z,3He)

Production of a 3He particle plus a residual. Sum of MT=750-799, if they are present.

107

(z,\(\alpha\))

Production of an alpha particle, plus a residual. Sum of MT=800-849, if they are present.

108

(z,2\(\alpha\))

Production of 2 alpha particles, plus a residual.

109

(z,3\(\alpha\))

Production of 3 alpha particles, plus a residual.

110

(Unassigned)

111

(z,2p)

Production of 2 protons, plus a residual.

112

(z,p\(\alpha\))

Production a proton and an alpha particle, plus a residual.

113

(z,t2\(\alpha\))

Production of a triton and 2 alpha particles, plus a residual.

114

(z,d2\(\alpha\))

Production of a deuteron and 2 alpha particles, plus a residual.

115

(z,pd)

Production of proton and a deuteron, plus a residual.

116

(z,pt)

Production of proton and a triton, plus a residual.

117

(z,d\(\alpha\))

Production of deuteron and an alpha particle, plus a residual.

118-119

(Unassigned)

120

Not allowed for version 6.

121-150

(Unassigned)

151

(n,RES)

Resonance parameters that can be used to calculate cross sections at different temperatures in the resolved and unresolved energy regions.

152-200

(Unassigned)

201

(z,Xn)

Total neutron production.

202

(z,X \(\gamma\))

Total gamma production.

203

(z,Xp)

Total proton production.

204

(z,Xd)

Total deuteron production.

205

(z,Xt)

Total triton production.

206

(z,X 3He)

Total 3He production.

207

(z,X\(\alpha\))

Total alpha particle production.

208

(z,X \(\pi^+\))

Total \(\pi^+\) production.

209

(z,X \(\pi^0\))

Total \(pi^0\) production.

210

(z,X \(\pi^-\))

Total \(\pi^-\) production.

211

(z,X :math:mu^+`)

Total \(\mu^+\) production.

212

(z,X \(\mu^-\))

Total \(\mu^-\) production.

213

(z,X\(\kappa^+\))

Total \(\kappa^+\) production.

214

(z,X\(\kappa^0_{long}\))

Total \(\kappa^0_{long}\) production.

215

(z,X\(\kappa^0_{short}\))

Total \(\kappa^0_{short}\) production.

216

(z,X\(\kappa^-\))

Total \(\kappa^-\) production.

217

(z,Xp)

Total anti-proton production.

218

(z,Xn)

Total anti-neutron production.

219-250

(Unassigned)

251

(n,…)

\(\bar{\mu}_{L}\), average cosine of the scattering angle (laboratory system) for elastic scattering of neutrons.

252

(n,…)

\(\xi\), average logarithmic energy decrement for elastic scattering of neutrons.

253

(n,…)

\(\gamma\), average of the square of the logarithmic energy decrement divided by twice the average logarithmic energy decrement, for elastic scattering of neutrons.

254-300

(Unassigned)

301-450

(z,…)

Energy release parameters,\(E * \sigma\), for total and partial cross sections; MT= 300 plus the reaction MT number, e.g., MT=302 is the elastic scattering kerma.

451

(z,…)

Heading or title information; given in File 1 only.

452

(z,…)

\(\bar{V}_{T}\), average total (prompt plus delayed) number of neutrons released per fission event.

453

(Unassigned)

454

(z,…)

Independent fission product yield data.

455

(z,…)

\(\bar{V} d\), average number of delayed neutrons released per fission event.

456

(z,…)

\(\bar{V} p\), average number of prompt neutrons released per fission event.

457

(z,…)

Radioactive decay data.

458

(n,…)

Energy release in fission for incident neutrons.

459

(z,…)

Cumulative fission product yield data.

460-464

(Unassigned)

465-466

Not allowed in version 6.

467-499

(Unassigned)

500

Total charged-particle stopping power.

501

Total photon interaction.

502

Photon coherent scattering.

503

(Unassigned)

504

Photon incoherent scattering.

505

Imaginary scattering factor.

506

Real scattering factor.

507-514

(Unassigned)

515

Pair production, electron field.

516

Pair production; sum of MT=515, 517.

517

Pair production, nuclear field.

518

Not allowed in version 6.

519-521

(Unassigned)

522

Photoelectric absorption.

523

Photo-excitation cross section.

524-525

(Unassigned)

526

Electro-atomic scattering.

527

Electro-atomic bremsstrahlung.

528

Electro-atomic excitation cross section.

529-531

(Unassigned)

532

Not allowed in version 6.

533

Atomic relaxation data.

534

K

(1s1/2) subshell photoelectric or electro-atomic cross section.

535

L1

(2s1/2) subshell photoelectric or electro-atomic cross section.

536

L2

(2p1/2) subshell photoelectric or electro-atomic cross section.

537

L3

(2p3/2) subshell photoelectric or electro-atomic cross section.

538

M1

(3s1/2) subshell photoelectric or electro-atomic cross section.

539

M2

(3p1/2) subshell photoelectric or electro-atomic cross section.

540

M3

(3p3/2) subshell photoelectric or electro-atomic cross section.

541

M4

(3d3/2) subshell photoelectric or electro-atomic cross section.

542

M5

(3d5/2) subshell photoelectric or electro-atomic cross section.

543

N1

(4s1/2) subshell photoelectric or electro-atomic cross section.

544

N2

(4p1/2) subshell photoelectric or electro-atomic cross section.

545

N3

(4p3/2) subshell photoelectric or electro-atomic cross section.

546

N4

(4dp3/2) subshell photoelectric or electro-atomic cross section.

547

N5

(4d5/2) subshell photoelectric or electro-atomic cross section.

548

N6

(4f5/2) subshell photoelectric or electro-atomic cross section.

549

N7

(4f7/2) subshell photoelectric or electro-atomic cross section.

550

O1

(5s1/2) subshell photoelectric or electro-atomic cross section.

551

O2

(5p1/2) subshell photoelectric or electro-atomic cross section.

552

O3

(5p3/2) subshell photoelectric or electro-atomic cross section.

553

O4

(5d3/2) subshell photoelectric or electro-atomic cross section.

554

O5

(5d5/2) subshell photoelectric or electro-atomic cross section.

555

O6

(5f5/2) subshell photoelectric or electro-atomic cross section.

556

O7

(5f7/2) subshell photoelectric or electro-atomic cross section.

557

O8

(5g7/2) subshell photoelectric or electro-atomic cross section.

558

O9

(5g9/2) subshell photoelectric or electro-atomic cross section.

559

P1

(6s1/2) subshell photoelectric or electro-atomic cross section.

560

P2

(6p1/2) subshell photoelectric or electro-atomic cross section.

561

P3

(6p3/2) subshell photoelectric or electro-atomic cross section.

562

P4

(6d3/2) subshell photoelectric or electro-atomic cross section.

563

P5

(6d5/2) subshell photoelectric or electro-atomic cross section.

564

P6

(6f5/2) subshell photoelectric or electro-atomic cross section.

565

P7

(6f7/2) subshell photoelectric or electro-atomic cross section.

566

P8

(6g7/2) subshell photoelectric or electro-atomic cross section.

567

P9

(6g9/2) subshell photoelectric or electro-atomic cross section.

568

P10

(6h9/2) subshell photoelectric or electro-atomic cross section.

569

P11

(6h11/2) subshell photoelectric or electro-atomic cross section.

570

Q1

(7s1/2) subshell photoelectric or electro-atomic cross section.

571

Q2

(7p1/2) subshell photoelectric or electro-atomic cross section.

572

Q3

(7p3/2) subshell photoelectric or electro-atomic cross section.

573-599

(Unassigned)

600

(z,p0)

Production of a proton leaving the residual nucleus in the ground state.

601

(z,p1)

Production of a proton, with residual in the 1st excited state.

602

(z,p2)

Production of a proton, with residual in the 2nd excited state.

603

(z,p3)

Production of a proton, with residual in the 3rd excited state.

604

(z,p4)

Production of a proton, with residual in the 4th excited state.

…

…

649

(z,pc)

Production of a proton in the continuum not included in the above discrete representation.

650

(z,d0)

Production of a deuteron leaving the residual nucleus in the ground state.

651

(z,d1)

Production of a deuteron, with the residual in the 1st excited state.

652

(z,d2)

Production of a deuteron, with the residual in the 2nd excited state.

…

…

699

(z,dc)

Production of a deuteron in the continuum not included in the above discrete representation.

700

(z,t0)

Production of a triton leaving the residual nucleus in the ground state.

701

(z,t1)

Production of a triton, with residual in the 1st excited state.

702

(z,t2)

Production of a triton, with residual in the 2nd excited state.

…

…

749

(z,tc)

Production of a triton in the continuum not included in the above discrete representation.

750

(n,:sup`3`He1)

Production of a 3He particle leaving the residual nucleus in the ground state.

751

(n,:sup`3`He2)

Production of a 3He, with residual in the 1st excited state.

…

…

799

(n,:sup`3`Hec)

Production of a 3He in the continuum not included in the above discrete representation.

800

(z,:math:alpha_0)

Production of an alpha particle leaving the residual nucleus in the ground state.

801

(z,:math:alpha_1)

Production of an alpha particle, with residual in the 1st excited state.

…

…

849

(z,:math:alpha_c)

Production of an alpha particle in the continuum not included in the above discrete representation.

850

(Unassigned)

851-870

Lumped reaction covariances.

871-874

(Unassigned)

875

(z,2n0)

Production of 2 neutrons with residual in the ground state.

876

(z,2n1)

Production of 2 neutrons with residual in the 1st excited state.

…

891

(z,2nc)

Production of 2 neutrons in the continuum not included in the above discrete representation.

892-999

(Unassigned)
Table 10.1.18 SCALE-Specific MT Reaction Types

SCALE MT

Description

1000

Transport cross section based on the outscatter approximation. See XSDRNPM chapter, section Outscatter approximation (inconsistent method).

1001

Transport cross section based on the inscatter approximation. See XSDRNPM chapter, section Inscatter approximation (consistent method)

1007

Thermal scattering matrix

1008

Elastic part of thermal scattering matrix

1018

Fission spectrum

1019

First chance fission spectrum

1020

Second chance fission spectrum

1021

Third chance fission spectrum

1038

Fourth chance fission spectrum

1099

Group integral of the weight function

1111

Flux moment (P1) weighted total cross section

1112

Flux moment (P2) weighted total cross section

1113

Flux moment (P3) weighted total cross section

1114

Flux moment (P4) weighted total cross section

1115

Flux moment (P5) weighted total cross section

1116

Flux moment (P6) weighted total cross section

1117

Flux moment (P7) weighted total cross section

1118

Flux moment (P8) weighted total cross section

1119

Flux moment (P9) weighted total cross section

1452

Product of \(\bar{V} T\) times the fission cross section

1456

Product of \(\bar{V}_{p}\) times the fission cross section

1455

Product of \(\bar{v}_{d}\) times the fission cross section

1500-1501

Same as 1000, 1001 except for gamma-ray cross sections

1527

Gamma-ray energy absorption coefficient factors

2006

Non-absorption collision probability (CE libraries only)

2016

Probability of emitting two neutrons (CE libraries only)

2017

Probability of emitting three neutrons (CE libraries only)

2018

Fission probability (CE libraries only)

2022

Within-group scattering cross section

2027

Absorption probability (CE libraries only)

4561

\(\bar{V}_{p}\) for first chance fissions

4562

\(\bar{V}_{p}\) for second chance fissions

4563

\(\bar{V}_{p}\) for third chance fissions

4564

\(\bar{V}_{p}\) for fourth chance fissions
XS1

The “residual” is the remainder after the reaction specified by MT has taken place (for example, A-1 after an n,2n reaction on target A). This “residual” may break up further if LR>0.

XS2(1,2)

Note that the partial fission cross sections are not defined for incident charged particles.