Nuclear Data Section
International Atomic Energy Agency
P.O.Box 100, A-1400 Vienna, Austria
Memo CP-D/710
Date:
To:
From:

11 August 2011
Distribution
N. Otsuka

Subject:

Total mass yield (MAS,FY)

From the description of LEXFOR “Fission Yields” (See Appendix of the memo), thefollowing two quantities are equivalent(…(N,F)MASS,SEC,FY) Post-neutron-emission fission-product yield(…(N,F)MASS,MAS,FY) Mass yield of fission fragment as sum of independent yield

Both REACTION codes give the sum of independent yields of all fission productswith a given mass. There are only 7 data sets coded with MAS (introduced in February2000) and they were checked.
Entry

REACTION (SF5-SF8)

Comments
Use PRE,FY (declared as pre-neutron13981.002 MAS,FY
emission mass-yield by authors)
Use SEC,FY/DE,*F,MXW/MSC (declared as
14044.003 PAR/MAS,FY,LF,REL/MXW
post-neutron-emission masses by authors)
14088.002 MAS,FY?
MAS,FY
14088.003?
Use SEC,FY (They obtainedMAS,FY
41496.003<A L >+<A H >=240.6, which is smaller thanthe compound mass.
A0108.245 MAS,FY
Use SEC,FY (on-line separation at GSI)Use SEC,FY ? (I cannot find an answer inO1442.002 MAS,FY
the article.)
Many of these authors use “mass yields” in their figures, and this is probably thereason why compilers selected MAS,FY. This is a good example to learn that selectionof quantity codes should not be based on the terminology but on the definition of thequantity.
I propose to make the following 3 codes obsolete.
Dictionary 31 (Branch Codes)
MAS
Obsolete
Dictionary 31 (Branch Codes)
MAS,FY
Obsolete
PAR/MAS,FY,LF
Obsolete

Appendix (Extraction from LEXFOR “Fission Yields”)
Secondary Fission-Fragment Yield
The secondary yield per fission of fission-fragment mass A after prompt-neutron
emission, but before β decay and delayed-neutron emission. It may also be called
post-neutron-emission fragment-mass distribution
Example: (…(N,F)MASS,SEC,FY)
Independent Fission-Product Yield
The direct or independent yield per fission of a primary fission product specified by Zand A; i.e., after prompt neutron emission, but before β decay and delayed-neutron
emission, including only the direct yield and not the yield obtained from decay ofother fission products.
Example: (…(N,F)ELEM/MASS,IND,FY)
Total Mass Yield
The total mass yield per fission of fragment mass A is the sum of the independent
yields of all fission products with the mass A.
Example: (…(N,F)MASS,MAS,FY)

Distribution:
blokhin@ippe.ru
cgc@ciae.ac.cn
chiba@earth.sgu.ac.jp
emmeric.dupont@oecd.org
fukahori.tokio@jaea.go.jp
ganesan@barc.gov.in
gezg@ciae.ac.cn
hongwei@ciae.ac.cn
jhchang@kaeri.re.kr
j.roberts@iaea.org
kaltchenko@kinr.kiev.uakatakura.junichi@jaea.go.jp
kato@nucl.sci.hokudai.ac.jp
kiralyb@atomki.hu
l.vrapcenjak@iaea.org
kiyoshi.matsumoto@oecd.org
manuel.bossant@oecd.org
manokhin@ippe.ru
mmarina@ippe.ru
mwherman@bnl.gov
nicolas.soppera@oecd.org
nklimova@kinr.kiev.ua

n.otsuka@iaea.org
nrdc@jcprg.org
oblozinsky@bnl.gov
ogritzay@kinr.kiev.ua
otto.schwerer@aon.at
pronyaev@ippe.ru
r.forrest@iaea.org
samaev@obninsk.ru
s.babykina@polyn.kiae.su
scyang@kaeri.re.kr
s.simakov@iaea.org
stakacs@atomki.hu
stanislav.hlavac@savba.sk
sv.dunaeva@gmail.com
taova@expd.vniief.ru
tarkanyi@atomki.hu
varlamov@depni.sinp.msu.ru
vlasov@kinr.kiev.ua
vmclane@optonline.net
v.semkova@iaea.org
v.zerkin@iaea.org
yolee@kaeri.re.kr
zhuangyx@ciae.ac.cn