Excitation functions for the helium-ion-induced fission of holmium and erbium

Journal Article · Sun Dec 01 04:00:00 EST 1991 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.44.2644· OSTI ID:5081902

Iyer, R H; Pandey, A K; Kalsi, P C; Sharma, R C ^[1]

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1. Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Bombay en400085 (India)

Excitation functions for the helium-ion-induced fission of holmium ({ital Z}=67) and erbium ({ital Z}=68) in the energy range 34--70 MeV were measured using lexan polycarbonate plastic as the fission fragment track detector. By analyzing the data in terms of the statistical model expression for {Gamma}{sub {ital f}}/{Gamma}{sub {ital n}}, the ratio of the fission width to neutron emission width, the fission barriers of the compound nuclei {sup 1}{sub 69}{sup 69}Tm and {sup 17}{sub 70}{sup 1.3}Yb were determined to be 29.8{plus minus}3 and 27.8{plus minus}3 MeV, respectively. The corresponding values for the fission level density parameter were found to be {ital a}{sub {ital f}}={ital A}/12 and {ital A}/13, respectively. The uncertainties shown in the fission barriers allow for inclusion of other values derived from reasonable upper and lower limits of {ital a}{sub {ital f}} values of {ital A}/8 to {ital A}/20. The measured fission barriers compare very well with the shell-corrected liquid-drop barriers of Myers and Swiatecki. The present measurements extend the range of low-{ital Z} elements which are away from the closed-shell region and which are studied at these medium energies. The results are compared with similar data available in the literature which bring out some interesting correlations and trends in the fission properties, viz., fission barriers and level density parameters of low-{ital Z} elements.

• OSTI ID: 5081902
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 44:6; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

663440* -- D-
T-
& He-induced Reactions & Scattering-- (1992-)
663470 -- Fission-- (1992-)
663570 -- Nuclear Mass Ranges-- A=150-189-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
CHARGED-PARTICLE REACTIONS
COMPOUND NUCLEI
CROSS SECTIONS
ELEMENTS
ENERGY RANGE
ENERGY-LEVEL DENSITY
EXCITATION FUNCTIONS
FISSION
FISSION BARRIER
FUNCTIONS
HOLMIUM 165 TARGET
INTERMEDIATE MASS NUCLEI
ISOTOPES
METALS
MEV RANGE
MEV RANGE 10-100
NUCLEAR POTENTIAL
NUCLEAR REACTIONS
NUCLEI
ODD-EVEN NUCLEI
POTENTIALS
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
RARE EARTHS
STABLE ISOTOPES
TARGETS
THULIUM 169
THULIUM ISOTOPES
YTTERBIUM