| Project/Area Number |
63880024
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Nuclear engineering
|
|---|
| Research Institution | TOHOKU UNIVERSITY |
|---|
Principal Investigator |
YOSHIHARA Kenji FACULTY OF SCIENCE, DEPARTMENT OF CHEMISTRY, PROFESSOR, 理学部, 教授 (90004423)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IZAWA Gunzo FACULTY OF SCIENCE, DEPARTMENT OF CHEMISTRY (UNTIL MARCH 31, 1989), ASSOCIATE PR, 理学部(平成元年3月31迄), 助教授 (80004373)
|
|---|
| Project Period (FY) |
1988 – 1989
|
| Project Status |
Completed (Fiscal Year 1989)
|
| Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1989: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥4,400,000 (Direct Cost: ¥4,400,000)
|
|---|
| Keywords | TRITIUM / RADIOACTIVE DECAY / ABRUPT ACOUSTIC EMISSION / PZT DETECTORS / GAS EMISSION TYPE SIGNALS / FRACTURE TYPE SIGNALS / HELIUM-3 EMISSION / ABC成分 / 超音波測定 |
|---|
| Research Abstract |
Acoustic emission after tritium decay was studied by using PZT detectors for the first time.
A measurement assembly consisted of a detector part and an acoustic analyzer (NF Wave Memory). There were sample and reference cells in the detector part to discriminate true acoustic signals from noises and false signals.
A sample of tritium adsorbed on a titanium evaporated film (base metal copper) was measured by the system. It was observed that abruptly arising signals appeared and usually decayed in 150mus. At least three kinds of signals containing Types A, B and C which have waves of about 2OOkHz, 4OOkHz and lOOkHz, respectively. Type A was most frequently observed. Combination of these patterns was sometimes appeared. After B had occurred then A was induced, and after A occurred C was induced sometimes. Repetition of A with time delay was also observed.
These signals could be compared with those by Betteridge et al. who studied acoustic emission from chemical reactions. Our signal of Type A was similar to those of gas emission type in their study. Type B resembled to their patterns of fracture type.
Emission of ^3He decayed from tritium was experimentally confirmed using a uadrapole mass filter. From this fact the signal of Type A could be related to ^3He gas emission.
Acoustic signals reflect physical states surrounding the sources of sounds. This will be an interesting problem to be studied in the future.
|
