| Isotope | Evaluation | MAT # |
| H(H2O) | Description | 1 |
| H(ZrH) | Description | 7 |
| H(CaH2) | Description | 8 |
| D(D2O) | Description | 11 |
| 4-Be | Description | 26 |
| Graphite | Description | 31 |
| H(CH2) | Description | 37 |
| 24-Mg | Description | 52 |
| Ca(CaH2) | Description | 59 |
==================================================================
H(H2O) IKE EVAL-JAN04 Keinert,Mattes
IKE 6-xxx DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 1
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: New evaluation **
** **
******************************************************************
* *
*----------------------------------------------------------------*
* Temperatures (K)= 293.6 323.6 373.6 423.6 473 .6 523.6 *
* 573.6 623.6 647.2 800 1000 *
* *
* Modifications compared to the JEF-2 data file : *
* - alpha,beta-grid strictly correlated to the phonon spectra *
* - modification of hindered rotational mode spectrum at high *
* frequencies *
* - oscillator frequency omega1=omega3 changed to 0.436 eV *
* - optical modes equally weighted *
*----------------------------------------------------------------*
==================================================================
H(ZrH) IKE EVAL-JAN05 Keinert
IKE report DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 7
----- THERMAL NEUTRON SCATTERING DATA
------ ENDF-6
***************************** JEFF-3.1 *************************
** **
** Original data taken from: New evaluation **
** **
******************************************************************
* *
* TEMPERATURES = 293.6 400 500 600 700 800 1000 1200 DEG K. *
* *
*---------------------------------------------------------------*
* IKE model for H in ZrH with *
* treating of Zr as free gas *
* *
* LEAPR/NJOY-99.90+ calculation done at IKE Stuttgart feb.2004 *
*---------------------------------------------------------------*
==================================================================
H(CaH2) CEA,ILL EVAL-OCT04 O.SEROT CEA Cadarache
DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 8
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: New evaluation **
** **
******************************************************************
Temperatures = 296. 400. 500. 600. 700. 800. 1000. 1200. K.
The present evaluation is based on measurements of CaH2 phonon
frequency spectra performed at the ILL high flux reactor
(Grenoble/France) (ref 1). The contribution of the Ca(OH)2
impurity has been removed.
The phonon frequency spectrum obtained has the following
characteristics:
- an acoustic mode, centered at around 20 meV.
- two optic mode bands centered respectively in the energy
range 70-100 meV and 110-140 meV. In each optic mode, fine
structures could be observed and explained from the known
crystal structure of CaH2 (ref 2,3).
In order to treat Hydrogen atom bound in CaH2, the acoustic mode
has been weighted relative to the optical modes by a factor 1/106
(see Ref.4).
This weighting factor was not deduced from rigorous lattice
dynamic model, but from physical grounds. This aspect could be
improved and further investigations are needed on the matter.
The S(alpha,beta) scattering laws have been generated using the
tools and methodologies given in ref 5. The alpha and beta grids
are the same as used for H in ZrH2 allowing energy transfers of
almost 2 eV at T=296. K.
The following ENDF MAT and MT's have been chosen in order to
remain compatible with other materials: MAT 8, MT 237 and 238 for
incoherent inelastic and elastic cross sections.
The following options have been used in the processing:
Leapr: spr 20.478, npr 1, iel 0
Thermr: icoh 0, natom 1, mtref 237
Acer: mti 237, mte 238, ielas 1 (incoherent elastic), nmix 1
REFERENCES
----------
1. P. Morris, D.K. Ross, S. Ivanov, D.R. Weaver and O. Serot,
"Inelastic neutron scattering study of the vibrations
frequencies of Hydrogen in Calcium Dihydride", International
Symposium on Metal-Hydrogen System (MH2002), Annecy, FRANCE
2. J. Bergsma and B.O. Loopstra, "The crystal Structure of
Calcium Hydride", Acta Cryst. 15 (1962) 92-93
3. A.F Andresen, A.J. Maeland and D. Slotfeldt-Ellingsen,
"Calcium Hydride and Deuteride studied by Neutron Diffraction
and NMR", Journal of Solid State Chemistry, 20, 93-101 (1997)
4. O. Serot, "New results on CaH2 thermal neutrons scattering
cross sections", Int. Conf. on Nuclear Data for Science and
Technology, Santa Fe, New Mexico, Sept. 2004, in press
5. R.E. MacFarlane, NJOY suite of manuals,"New Thermal Neutron
Scattering Files for ENDF/B-VI release 2", August 1994
==================================================================
D(D2O) IKE EVAL-FEB04 Keinert,Mattes
IKE report DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 11
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: New evaluation **
** **
******************************************************************
* *
*----------------------------------------------------------------*
*Temperatures: 293.6 323.6 373.6 423.6 473.6 523.6 573.6 643.9 K *
* *
* Incoherent approximation improved by intermolecular *
* D-D interference according to the Sköld approximation *
* *
*----------------------------------------------------------------*
==================================================================
4-Be IKE EVAL-DEC89 J.KEINERT M.MATTES IKE
DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 26 REVISION 0
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: JEFF-3.0 **
** **
******************************************************************
***************************** JEFF-3.0 ***********************
DATA TAKEN FROM :- JEF-2.2 (DIST-JUL91 REV1-JUL91)
******************************************************************
******************************************************************
* Beryllium - Thermal Neutron Scattering Law Data in MF=7 *
* are given for the temperatures *
* T=293.6 400 500 600 700 800 1000 1200 K *
* *
* - Coherent Elastic Scattering (MT=2): The quantity actually *
* given in the file is S(E,T), which is conveniently repre- *
* sented as a stair-step function with breaks at the Bragg *
* edges using histogram interpolation. *
* Bragg edges and structure factors are derived from the *
* cross section. *
* *
* - Incoherent Inelastic Scattering (MT=4) is represented by *
* the thermal neutron scattering law S(alpha,beta,T). *
* *
* S(alpha,beta) are taken from the *
* IKE scattering law data file *
* and converted to ENDF-6 format. The number of principal atoms *
* is added, and the principal atom scattering cross section *
* agrees now with the current general purpose evaluation. Also *
* the effective temperatures for the principal atom are added. *
* july 1991 Mattes/IKE *
******************************************************************
* *
* The frequency spectrum of polycrystalline Beryllium was derived*
* from a central force lattice dynamical model calculation of the*
* unit cell /1,2/. With this frequency distribution the *
* thermal scattering law data have been generated in incoherent *
* approximation with the code GASKET /3/ for 8 temperatures from *
* room temperature up to 1200K. A maximum neutron energy transfer*
* of 1.8554 eV was assumed. Greater energy transfers can be *
* computed with the Short Collision Time (SCT) approximation *
* using the corresponding effective scattering temperatures *
* T_eff. This is done e.g. in the THERMR module of the NJOY *
* nuclear data processing system /4/. *
*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*
* Data for intermediate temperatures should be obtained by inter-*
* polating between the resulting cross sections and not by inter-*
* polating S(alpha,beta). *
******************************************************************
* References *
* /1/ J.A.Young,J.U.Koppel: NSE 19,367 (1964) *
* /2/ J.U.Koppel,D.H.Houston: GA-8774 (1968) *
* /3/ J.U.Koppel,U.R.Triplett,Y.D.Naliboff: GA-7417 (1966) *
* /4/ R.E.MacFarlane,D.W.Muir,R.M.Boicourt: LA-9303-M (ENDF-324) *
* (1983) *
******************************************************************
==================================================================
Graphite IKE EVAL-JAN05 Keinert, Mattes
IKE- DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 31
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: New evaluation **
** **
******************************************************************
*----------------------------------------------------------------*
* Temperatures (K) = 293.6, 400, 500, 600, 700, 800, 1000, *
* 1200, 1600, 2000, 3000 *
* *
*----------------------------------------------------------------*
==================================================================
H(CH2) IKE EVAL-SEP81 J.KEINERT M.MATTES IKE
DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 37
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: JEFF-3.0 **
** **
******************************************************************
***************************** JEFF-3.0 ***********************
DATA TAKEN FROM :- JEF-2.2 (DIST-JAN92)
JEF Report 2 (1984) DIST-NOV90 REV1 JUN90
******************************************************************
******************************************************************
* Polyethylene - Thermal Neutron Scattering Law Data in MF=7 *
* H (CH2) are given for the temperatures *
* T= 293.6 and 350 K *
* *
* - Incoherent Elastic Scattering (MT=2) is represented using *
* a bound cross section and Debye-Waller integral given in *
* in the file as W'(T) divided by the atomic mass (1/eV) as *
* a function of temperature (K). *
* *
* - Incoherent Inelastic Scattering (MT=4) is represented by *
* the thermal neutron scattering law S(alpha,beta,T). *
* *
* S(alpha,beta) are taken from *
* JEF-1 MAT=4004 scattering law data file *
* and converted to ENDF-6 format. The number of principal atoms *
* is added, and the principal atom scattering cross section *
* agrees now with the current general purpose evaluation. Also *
* the effective temperatures for the principal atom are added. *
* july 1991 Mattes/IKE *
******************************************************************
* *
* The phonon frequency spectrum of hydrogen bound in polyethylene*
* was derived by Sprevak,Koppel /1/ in calculating the dispersion*
* relations for the infinite chain of CH2 radicals as well as the*
* polarization vector for each normal frequency using the set of *
* force constants determined by Lin, Koenig /2/. The weighted *
* frequency spectrum was then calculated using the computed *
* dispersion relations and the computed amplitude vectors. *
* *
* The S(alpha,beta) data are generated for one hydrogen atom in *
* the CH2 molecule in incoherent approximation for 2 temperatures*
* with the code GASKET /3/. A maximum neutron energy transfer of *
* 1.8554 eV was used. Greater energy transfers can be computed *
* with the 'Short Collision Time' (SCT) approximation using the *
* corresponding effective scattering temperatures T_eff. This is *
* done e.g. in the THERMR module of the NJOY nuclear data *
* processing system /4/. *
*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*
* Data for intermediate temperatures should be obtained by inter-*
* polating between the resulting cross sections and not by inter-*
* polating S(alpha,beta). *
******************************************************************
* References *
* /1/ D.Sprevak,J.U.Koppel: NUKLEONIK 12,87 (1969) *
* /2/ T.P.Lin,J.L.Koenig: J.Molec.Spectra 9,228 (1962) *
* /3/ J.U.Koppel,U.R.Triplett,Y.D.Naliboff: GA-7411 (1966) *
* /4/ R.E.MacFarlane,D.W.Muir,R.M.Boicourt: LA-9303-M (ENDF-324) *
* (1983) *
******************************************************************
==================================================================
24-Mg CEA EVAL-SEP03 C.MOUNIER
DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 52
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: New evaluation **
** **
******************************************************************
TEMPERATURES = 20 100 296 773 DEG K.
All the theory involved in this evaluation is fully explained in
report [1] which contains the theory of the LEAPR module of NJOY.
Mg metal has hexagonal close-packed lattice structure
like Be metal with the geometrical constants (a,c)
equal to 3.2094E-8 cm and 5.2108E-8 cm respectively.
The bound coherent scattering cross-section is set to 3.613 barns
and the free scattering cross section to 3.418 barns.
The validation of this evaluation is detailled in paper [2].
REFERENCES
[1] R.E.Macfarlane,"New thermal neutron scattering files for
endf/b-vi release 2", los alamos national laboratory report
LA-12639-MS (ENDF-356) March 1994.
[2] C. Mounier, "Thermal neutron cross-sections of magnesium"
==================================================================
Ca(CaH2) CEA,ILL EVAL-OCT04 O.SEROT CEA Cadarache
DIST-MAY05 REV1-MAY05 20050504
----JEFF-31 MATERIAL 59
-----THERMAL NEUTRON SCATTERING DATA
------ENDF-6 FORMAT
***************************** JEFF-3.1 *************************
** **
** Original data taken from: New evaluation **
** **
******************************************************************
Temperatures = 296. 400. 500. 600. 700. 800. 1000. 1200. K.
The present evaluation is based on measurements of CaH2 phonon
frequency spectra performed at the ILL high flux reactor
(Grenoble/France) (ref 1). The contribution of the Ca(OH)2
impurity has been removed.
The phonon frequency spectrum obtained has the following
characteristics:
- an acoustic mode, centered at around 20 meV.
- two optic mode bands centered respectively in the energy
range 70-100 meV and 110-140 meV. In each optic mode, fine
structures could be observed and explained from the known
crystal structure of CaH2 (ref 2,3).
In order to treat Calcium atom bound in CaH2, the acoustic mode
has been weighted relative to the optical modes by a factor
105/106 (see Ref.4).
This weighting factor was not deduced from rigorous lattice
dynamic model, but from physical grounds. This aspect could be
improved and further investigations are needed on the matter.
The S(alpha,beta) scattering laws have been generated using the
tools and methodologies given in ref 5. The alpha and beta grids
are the same as used for H in CaH2 allowing energy transfers of
almost 2 eV at T=296. K.
The following ENDF MAT and MT's have been chosen in order to
remain compatible with other materials: MAT 59, MT 239 and 240
incoherent inelastic and elastic cross sections.
The following options have been used in the processing:
Leapr: spr 3.0193, npr 1, iel 0
Thermr: icoh 0, natom 1, mtref 239
Acer: mti 239, mte 240, ielas 1 (incoherent elastic), nmix 1
REFERENCES
----------
1. P. Morris, D.K. Ross, S. Ivanov, D.R. Weaver and O. Serot,
"Inelastic neutron scattering study of the vibrations
frequencies of Hydrogen in Calcium Dihydride", International
Symposium on Metal-Hydrogen System (MH2002), Annecy, FRANCE
2. J. Bergsma and B.O. Loopstra, "The crystal Structure of
Calcium Hydride", Acta Cryst. 15 (1962) 92-93
3. A.F Andresen, A.J. Maeland and D. Slotfeldt-Ellingsen,
"Calcium Hydride and Deuteride studied by Neutron Diffraction
and NMR", Journal of Solid State Chemistry, 20, 93-101 (1997)
4. O. Serot, "New results on CaH2 thermal neutrons scattering
cross sections", Int. Conf. on Nuclear Data for Science and
Technology, Santa Fe, New Mexico, Sept. 2004, in press
5. R.E. MacFarlane, NJOY suite of manuals,"New Thermal Neutron
Scattering Files for ENDF/B-VI release 2", August 1994
Last reviewed: 27 October 2010
