Nuclear Data Section
International Atomic Energy Agency
P.O.Box 100, A-1400 Vienna, Austria
Memo CP-D/512

Date:
To:
From:

19 August 2008
Distribution
N. Otsuka, R. Capote Noy, S. Dunaeva

Subject:

Level density compilation

The level density is an essential quantity in the statistical model calculation of nuclear
reactions, which depends on the excitation energy of the nucleus. Its energy
dependence has been empirically approximated by different phenomenologicalmodels, being a constant temperature and Fermi gas models widely employed. Somerelated nuclear quantities for these models are defined in Dictionary 236 (Leveldensity parameter LDP, spin-cut-off factor SCO and nuclear temperature TEM).
However, it was not possible to compile into EXFOR new pointwise measurements of
the level density in a wide energy region.
Two new techniques have been developed for extraction of energy dependent level
density in a wide energy range:1) Level density derived from primary γ spectra:
Extraction of level density ρ(E i - E γ ) from the primary γ matrix Γ(E i , E γ ) on theassumption that,F ( Eγ ) ρ ( E i − Eγ )Γ(Ei , Eγ ) = Ei
∑E = E min F (Eγ )ρ ( Ei − Eγ )γγ, where E i , E γ and F(E γ ) are the initial level of γ decay, γ energy and radiativetransmission coefficient (Eq.(2) of [1]).
2) Level density derived from particle emission spectra:
Extraction of level density ρ b (E, I, π) from particle emission spectra dσ/dε b based on
the Hauser-Feshbach model.
∑I ,π Γb (U , J , π , E , I , P) ρ b ( E , I , P)dσ(ε a , ε b ) = ∑ σ CN (ε a )dε bΓ(U , J , π )J ,πCN, where ε a , ε b , σ (ε a ), Γ b , (U, J, π), (E, I, P) are relative energies for initial and final
channels, compound formation cross section, transmission coefficient, (excitationenergy, angular momentum and parity) of compound, and residual nuclei, respectively(Eq.(2) of [2]).
We hereby propose new codes for the compilation of numerical data of level
density extracted by methods (1) and (2).

Dictionary 22 (Analysis codes)
PGS
Extraction of the LD from primary gamma spectra
PES
Extraction of the LD from equilibrium particle emission spectra

Dictionary 236 (Quantities),LD
Level density
Quantity,LDReaction TypeNQ

Dimension
1/E

Subentry

Reference[1] A. Schiller et al., Nucl. Instrum. Meth. Phys.Res.A447(2000)498[2] A.V.Voinov et al., Phys.Rev.C74 (2006)014314.

Distribution:
a.mengoni@iaea.org
a.nichols@iaea.org
blokhin@ippe.ru
chiba@earth.sgu.ac.jp
claes.nordborg@oecd.org
ganesan@barc.gov.in
gezg@ciae.ac.cn
hasegawa@nea.fr
henriksson@near.fr
hongwei@ciae.ac.cn
jhchang@kaeri.re.kr
kaltchenko@kinr.kiev.ua
katakura.junichi@jaea.go.jp
kato@nucl.sci.hokudai.ac.jp
kirarlyb@atomki.hu
l.vrapcenjak@iaea.org
manokhin@ippe.ru
mmarina@ippe.ru
cc:r.capotenoy@iaea.org

mwherman@bnl.gov
nklimova@kinr.kiev.ua
n.otsuka@iaea.org
nrdc@jcprg.org
oblozinsky@bnl.gov
ogritzay@kinr.kiev.ua
samaev@obninsk.ru
s.babykina@polyn.kiae.su
s.dunaeva@iaea.org
stakacs@atomki.hu
stanislav.hlavac@savba.sk
taova@exped.vniief.rutarkanyi@atomki.hu
varlamov@depni.sinp.msu.ru
vlasov@kinr.kiev.ua
vmclane@optonline.net
v.zerkin@iaea.org
yolee@kaeri.re.kr

Coding sample
SUBENT
BIB
TITLE

D9901001
20080730
D990100100001
1122
D990100100002
Thermal and electromagnetic properties of 166Er andD990100100003
167Er
D990100100004
AUTHOR(E.Melby, M.Guttormsen, J.Rekstad, A.Schiller, S.Siem) D990100100005
INSTITUTE (2NOROSL) Department of Physics
D990100100006
REFERENCE (J,PR/C,63,(4),044309,200104)
D990100100007
SAMPLE- Target enrichment is 95.6%.
D990100100008- Chemical-form of target is element.
D990100100009- Target-thickness is 1.5 mg/cm**2.
D990100100010- Target is self supported.
D990100100011
FACILITY(CYCLO,2NOROSL) To accelerate 3He to 45 MeV at Oslo
D990100100012
Cyclotron Laboratory
D990100100013
ANALYSIS(UNFLD) Corrected for response of NaI detectors
D990100100014(PGS) Level density from primary gamma matrix
D990100100015
DETECTOR(TELES,SI,SILI) To detect charged particles
D990100100016(NAICR) To detect primary gammas
D990100100017
ERR-ANALYS (DATA-ERR) No information on source of uncertainties
D990100100018
REL-REF
(N,,A.Schiller+,J,NIM/A,447,498,2000)
D990100100019
Method to extract level density from gamma spectra
D990100100020(R,,R.B.Firestone+,B,FIRESTONE,,,1996)
D990100100021
Discrete levels at low excitation energy forD990100100022
normalization
D990100100023
HISTORY(20080730C) On
D990100100024
ENDBIB220
D990100100025
NOCOMMON00
D990100100026
ENDSUBENT
250
D990100199999
SUBENT
D9901002
20080730
D990100200001
BIB
46
D990100200002REACTION(68-ER-166(0,0),,LD)
D990100200003
Derived from 167Er(3He,a)166Er* reaction
D990100200004
PART-DET(A,G)
D990100200005
EN-SEC(E-EXC,68-ER-166)
D990100200006
STATUS(TABLE) Data (Fig.4, p044309-3 of reference) taken
D990100200007
from Oslo's compilation (http://ocl.uio.no/)D990100200008
ENDBIB60
D990100200009
NOCOMMON00
D990100200010
DATA
343
D990100200011
E-EXC
DATA
DATA-ERR
D990100200012
MEV
1/MEV
1/MEV
D990100200013
0.025
5.620E-01 1.500E-01
D990100200014
0.145
1.120E+00 2.060E-01
D990100200015
0.265
1.810E+00 2.820E-01
D990100200016…
4.705
2.030E+04 2.170E+03
D990100200053
4.825
2.980E+04 3.030E+03
D990100200054
4.945
3.330E+04 3.480E+03
D990100200055
5.065
3.540E+04 4.360E+03
D990100200056
ENDDATA
450
D990100200057
ENDSUBENT
560
D990100299999