Reference input spectra¶

The collapsed cross-sections depend strongly on the nature of the projectile spectra, and so it is important to use the appropriate spectrum together with the appropriately-weighted cross-section data. With the advances of modern simulation software and high resolution spectra the user is reminded of the importance of the tails, low or high-energy ones, on the reaction rates.

The majority of neutron-application spectra stem from light-water assemblies, mock-ups or reactors where the integral responses are strongly, if not solely, influenced by the energy ranges of the fission spectra and thermal maxwellian. Fusion spectra that have been obtained from magnetic confinement (MCF) or inertial confinement fusion (ICF) present typical D-D 2.5 MeV, or D-T 14 MeV peaks sometimes accompanied by a higher-energy tail, but also showing rather different slowing-down profiles. Accelerator-driven beam spectra are important in their role in nuclear data acquisition and materials research, but also for medical therapeutic and diagnostic applications.

In essence the particle spectrum profile, through the collapsing process, emphasises the energy region of most importance for each application. Transferring data from one application or energy range to another should be done with great care as it can easily lead to misleading and inappropriate numerical results.

Several incident particle spectra are provided in the table below, mostly including neutron incident spectra but with some charged particle spectra. Note that these are provided in the original energy group structures as generated by the code(s) that calculated them. These are often not the same energy group structures as those provided for e.g. the TENDL nuclear data libraries and require a flux conversion using GRPCONVERT. Note that while the group conversion can easily be performed, this cannot add structure when moving to a refined group structure when moving to a more refined multi-group.

Each of the spectra below is provided in the format of an arbitrary flux arb_flux file for reading in the GRPCONVERT module as well as a figure showing the spectrum in flux per unit lethargy using an arbitrary normalisation. For convenience, all of the arb_flux files are available in the table below.

Reference incident particle spectra

Name	Group	Particle	arb_flux file	Figure	Description
Bigten	407	n	407 Bigten.txt	Bigten	International Criticality Safety Benchmark Experiment, Bigten
BOR60	69	n	69_bor60.txt		BOR-60 fast test reactor
BWR-MOX-Gd-0	1102	n	1102 BWR-MOX-Gd-0.txt	BWR-MOX-Gd-0	BWR MOX fuel with Gd, 0 GWd/THM
BWR-MOX-Gd-15	1102	n	1102 BWR-MOX-Gd-15.txt	BWR-MOX-Gd-15	BWR MOX fuel with Gd, 15 GWd/THM
BWR-MOX-Gd-40	1102	n	1102 BWR-MOX-Gd-40.txt	BWR-MOX-Gd-40	BWR MOX fuel with Gd, 40 GWd/THM
BWR-RPV	198	n	198 BWR-RPV.txt	BWR-RPV	Boiling water reactor, ¼ Thickness reactor pressure vessel
BWR-UO2-Gd-0	1102	n	1102 BWR-UO2-Gd-0.txt	BWR-UO2-Gd-0	BWR UO2 fuel with Gd, 0 GWd/THM
BWR-UO2-Gd-15	1102	n	1102 BWR-UO2-Gd-15.txt	BWR-UO2-Gd-15	BWR UO2 fuel with Gd, 15 GWd/THM
BWR-UO2-Gd-40	1102	n	1102 BWR-UO2-Gd-40.txt	BWR-UO2-Gd-40	BWR UO2 fuel with Gd, 40 GWd/THM
CERN-H4IRRAD	288	n	288 CERN-H4IRRAD.txt	CERN-H4IRRAD	CERN H4IRRAD experiment
Cf252	070	n	070 Cf252.txt	Cf252	Californium-252 spontaneous fission source
DEMO-HCPB-BP	616	n	616 DEMO-HCPB-BP.txt	DEMO-HCPB-BP	DEMO fusion concept He-cooled pebble bed, backplate
DEMO-HCPB-FW	616	n	616 DEMO-HCPB-FW.txt	DEMO-HCPB-FW	DEMO fusion concept He-cooled pebble bed, first wall
DEMO-HCPB-VV	616	n	616 DEMO-HCPB-VV.txt	DEMO-HCPB-VV	DEMO fusion concept He-cooled pebble bed, vacuum vessel
EBR-2	029	n	029 EBR-2.txt	EBR-2	Experimental Breeder Reactor spectrum
Frascati-NG	175	n	175 Frascati-NG.txt	Frascati-NG	ENEA Frascati Neutron Generator D-T
HCLL-FW	616	n	616 HCLL-FW.txt	HCLL-FW	D-T fusion reactor He-cooled LiPb, first wall
HCLL-VV	616	n	616 HCLL-VV.txt	HCLL-VV	D-T fusion reactor He-cooled LiPb, vacuum vessel
HCPB-FW	616	n	616 HCPB-FW.txt	HCPB-FW	D-T fusion reactor He-cooled pebble bed, first wall
HCPB-VV	616	n	616 HCPB-VV.txt	HCPB-VV	D-T fusion reactor He-cooled pebble bed, vacuum vessel
HFIR-highres	238	n	238 HFIR-highres.txt	HFIR-highres	Material test reactor, Oak Ridge HFIR midplane
HFIR-lowres	100	n	100 HFIR-lowres.txt	HFIR-lowres	Material test reactor, Oak Ridge HFIR midplane
HFIR-VXF3-AD	238	n	238 HFIR-VXF3-AD.txt	HFIR-VXF3-AD	Material test reactor, Oak Ridge HFIR midplane-VXF3-AD
HFR-high	616	n	616 HFR-high.txt	HFR-high	Material test reactor, Petten HFR high
HFR-low	616	n	616 HFR-low.txt	HFR-low	Material test reactor, Petten HFR low
IFMIF-DLi	211	n	211 IFMIF-DLi.txt	IFMIF-DLi	IFMIF D-Li neutron source
ITER-DD	175	n	175 ITER-DD.txt	ITER-DD	Magnetic confinement fusion, ITER D-D
ITER-DT	175	n	175 ITER-DT.txt	ITER-DT	Magnetic confinement fusion, ITER D-T
JAEA-FNS	175	n	175 JAEA-FNS.txt	JAEA-FNS	JAEA Fusion Neutron Source D-T
JET-FW	100	n	100 JET-FW.txt	JET-FW	Joint European Torus, first wall vacuum vessel
LMJ-g	161	γ	161 LMJ-g.txt	LMJ-g	Laser Mégajoule gamma spectra
Maxwellians	709	n	1 keV 5 keV 10 keV 30 keV 80 keV	Maxwellians	Maxwellian neutron spectra at various temperatures
NIF-ignition	150	n	150 NIF-ignition.txt	NIF-ignition	Inertial confinement fusion, NIF ignited
Paluel	172	n	172 Paluel.txt	Paluel	Paluel light water reactor
Phenix	172	n	172 Phenix.txt	Phenix	Fast breeder reactor, Phénix
PWR-MOX-0	1102	n	1102 PWR-MOX-0.txt	PWR-MOX-0	PWR MOX fuel with Gd, 0 GWd/THM
PWR-MOX-15	1102	n	1102 PWR-MOX-15.txt	PWR-MOX-15	PWR MOX fuel with Gd, 15 GWd/THM
PWR-MOX-40	1102	n	1102 PWR-MOX-40.txt	PWR-MOX-40	PWR MOX fuel with Gd, 40 GWd/THM
PWR-RPV	198	n	198 PWR-RPV.txt	PWR-RPV	Pressurized water reactor, ¼ Thickness reactor pressure vessel
PWR-UO2-0	1102	n	1102 PWR-UO2-0.txt	PWR-UO2-0	PWR UO2 fuel, 0 GWd/THM
PWR-UO2-15	1102	n	1102 PWR-UO2-15.txt	PWR-UO2-15	PWR UO2 fuel, 15 GWd/THM
PWR-UO2-40	1102	n	1102 PWR-UO2-40.txt	PWR-UO2-40	PWR UO2 fuel, 40 GWd/THM
PWR-UO2-Gd-0	1102	n	1102 PWR-UO2-Gd-0.txt	PWR-UO2-Gd-0	PWR UO2 fuel with Gd, 0 GWd/THM
PWR-UO2-Gd-15	1102	n	1102 PWR-UO2-Gd-15.txt	PWR-UO2-Gd-15	PWR UO2 fuel with Gd, 15 GWd/THM
PWR-UO2-Gd-40	1102	n	1102 PWR-UO2-Gd-40.txt	PWR-UO2-Gd-40	PWR UO2 fuel with Gd, 40 GWd/THM
Superphenix	172	n	172 Superphenix.txt	Superphenix	Fast breeder reactor, Superphénix
TUD-NG	175	n	175 TUD-NG.txt	TUD-NG	TU Dresden fusion neutron source D-T
WCCB-FW	616	n	616 WCCB-FW.txt	WCCB-FW	D-T fusion water-cooled ceramic breeder, first wall
WCCB-VV	616	n	616 WCCB-VV.txt	WCCB-VV	D-T fusion water-cooled ceramic breeder, vacuum vessel
WCLL-FW	616	n	616 WCLL-FW.txt	WCLL-FW	D-T fusion water-cooled LiPb, first wall
WCLL-VV	616	n	616 WCLL-VV.txt	WCLL-VV	D-T fusion water-cooled LiPb, vacuum vessel