Experimental study of time reversal invariance and atomic final state effects in nuclear transitions

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5188789

Gimlett, J L

Experiments have been performed to test time reversal invariance in nuclei using gamma transitions of oriented /sup 191/Ir and /sup 131/Xe. The phase angle eta associated with the imaginary part of the ratio of reduced matrix elements of the gamma transition was measured through observation of the angular distribution of the linear polarization from oriented nuclei. Interaction of the gamma ray with the atomic electron cloud can cause an additional phase shift xi which is indistinguishable from the time-reversal phase eta. Such an atomic final state effect has been observed for the 129 keV transition in /sup 191/Ir. Nuclear orientation was achieved with a large magnetic field (the hyperfine field of Ir in iron) and low temperature (20 to 30 mK obtained with a dilution refrigerator). A Compton polarimeter was used to measure linear polarization of the E2-M1 gamma ray. The matrix-element ratio was found to have an imaginary part corresponding to a phase angle (eta + xi) = (-4.8 +- 0.2) x 10/sup -3/. This measurements is in agreement with the most recent final state calculations which give xi = (-4.3 +- 0.4) x 10/sup -3/. A limit (eta) < 10/sup -3/ is deduced for the time-reversal phase. In another experiment a phase angle eta = (-1.2 +- 1.1) x 10/sup -3/ was measured for the E2-M1 364 keV transition in /sup 131/Xe, for which atomic final state effects are small. Both measurements are consistent with time reversal invariance.

• Research Organization: California Inst. of Tech., Pasadena (USA)
• OSTI ID: 5188789
• Country of Publication: United States
• Language: English

Related Subjects

651723* -- Nuclear Properties &amp; Reactions
A=90-149
Experimental-- Energy Levels &amp; Transitions-- (-1987)
651923 -- Nuclear Properties &amp; Reactions
A=190-219
Experimental-- Energy Levels &amp; Transitions-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DAYS LIVING RADIOISOTOPES
ENERGY-LEVEL TRANSITIONS
EVEN-ODD NUCLEI
HEAVY NUCLEI
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
INVARIANCE PRINCIPLES
IRIDIUM 191
IRIDIUM ISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
STABLE ISOTOPES
T INVARIANCE
XENON 131
XENON ISOTOPES