FISSION OF Th$sup 232$ NUCLEI BY NEGATIVE $mu$- AND $pi$-MESONS (in Russian)
Journal Article
·
· Doklady Akad. Nauk S.S.S.R.
OSTI ID:4229424
Heavy nuclei fission by mu /sup -/ mesons is possible through nuclear excitation in the mu /sup -/ optic transition 2p--1s in a mesoatom. Fission occurs when the transition exceeds the photoproduction threshold and when mesons are absorbed by nucleons in reactions such as mu /sup -/ + p yields - n + nu . The possibility of non-radiative excitation of nuclei according to the first type of event, with gamma emission in the radiation transition followed by nuclear excitation, was observed previously. An attempt is made to obtain data on the non-radiative fission of thorium. In addition to studies of thorium fission by mu /sup -/, studies are made of fission in pi /sup -/ capture; in evaluating the probability of the first process it is imperative to know the effect of pi /sup - / capture, as the mu /sup -/ beam is not pure. Some 11,075 pi /sup -/ capture events were observed, and the star distribution was compared with previously reported data. lt was determined that the mu /sup -/ contribution was about 15%. Consequently, of the observed 11,075 captures 9400 are related to / pi /sup -/ mesons. In 17 fissions in the same area, --0.5 events were related to mu /sup -/ . Hence, the probability P( pi /sup -/) in which the pi /sup -/capture can initiate fission is equal to (1.8 plus or minus 0.4) x 10/sup -3/. Capture events totaling 11,270 were observed ftn plates irradiated by mu /sup -/ containing 0.2 plus or minus 0.1% pi /sup -/. It was assumed that not more than 0.1% fissions result from pi /sup -/ capture. The probability P( mu ) with which mu /sup -/ induces fission is (2.7 plus or minus 17) x 10/sup -4/. The results confirm that there is slight probability of catalytic thorium fission by mu /sup -/ through non-radiative capture. The evaluation of the internal conversion probability showed one catalytic fission event requires nearly 300 mu /sup -/ captures. (R.V.J.)
- Research Organization:
- Joint Inst. of Nuclear Research, Dubna, U.S.S.R.
- NSA Number:
- NSA-13-018503
- OSTI ID:
- 4229424
- Journal Information:
- Doklady Akad. Nauk S.S.S.R., Journal Name: Doklady Akad. Nauk S.S.S.R. Vol. Vol: 126
- Country of Publication:
- Country unknown/Code not available
- Language:
- Russian
Similar Records
NUCLEAR FISSION INDUCED BY RADIATIONLESS TRANSITIONS IN THE MU-MESONIC ATOMS Th$sup 232$, U$sup 235$, AND U$sup 238$ (thesis)
On $mu$-Mesonic Fission; O DELENII YADER $mu$ MEZONOM
RADIATIVE CAPTURE OF $mu$$sup -$-MESON BY A PROTON
Technical Report
·
Tue May 01 00:00:00 EDT 1962
·
OSTI ID:4801650
On $mu$-Mesonic Fission; O DELENII YADER $mu$ MEZONOM
Technical Report
·
Fri Oct 30 23:00:00 EST 1959
·
OSTI ID:4284524
RADIATIVE CAPTURE OF $mu$$sup -$-MESON BY A PROTON
Journal Article
·
Wed Oct 31 23:00:00 EST 1962
· Zh. Eksperim. i Teor. Fiz.
·
OSTI ID:4760097