An improvement in the value of the energy of the first excited state in [sup 229]Th

Technical Report · Thu Apr 01 04:00:00 EST 1993

DOI:https://doi.org/10.2172/6326722· OSTI ID:6326722

Helmer, R G; Reich, C W

It has been known for many years that the first excited state of [sup 229]Th lies close to the ground state. Originally this energy was given as < 0.1 keV; later, the authors reported a value of [minus]1 [plus minus] 4 eV. Since the existence of a nuclear state at this very low energy is of considerable interest, measurements of its energy, half-life and modes of excitation and deexcitation are important. In an attempt to improve the level energy, the authors have measured over 175 [gamma]-ray spectra with several combinations of radionuclides. In comparison with their earlier study, they have considered more [gamma] rays in [sup 229]Th, used more well-measured reference lines, used more detectors, used detectors with better low-energy resolution, more closely matched peak count rates, and specifically considered certain systematic errors. From this large set of measurements they have deduced a value of 3.5 [plus minus] 1.0 eV for the energy of this level.

• Research Organization: EG and G Idaho, Inc., Idaho Falls, ID (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6326722
• Report Number(s): EGG-NRP-10693; ON: DE93016594
• Country of Publication: United States
• Language: English

Related Subjects

663110* -- General &amp; Average Properties of Nuclei &amp; Nuclear Energy Levels-- (1992-)
663590 -- Nuclear Mass Ranges-- A=220 &amp; Above-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
AMERICIUM 241
AMERICIUM ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BINDING ENERGY
COMPARATIVE EVALUATIONS
DATA
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ENERGY
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EV RANGE
EV RANGE 01-10
EVALUATION
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXCITATION
EXCITED STATES
EXPERIMENTAL DATA
GAMMA SPECTRA
GROUND STATES
HAFNIUM 172
HAFNIUM ISOTOPES
HALF-LIFE
HEAVY ION DECAY RADIOISOTOPES
HEAVY NUCLEI
INFORMATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LUTETIUM 172
LUTETIUM ISOTOPES
MEASURING INSTRUMENTS
MINUTES LIVING RADIOISOTOPES
NEON 24 DECAY RADIOISOTOPES
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
RADIATION DETECTORS
RADIOISOTOPES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
SPECTRA
SPONTANEOUS FISSION RADIOISOTOPES
TERBIUM 161
TERBIUM ISOTOPES
THORIUM 229
THORIUM ISOTOPES
URANIUM 233
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES