By using very precise

highly sensitive

static accumulated

easily repeated CD- 1 a -cup to survey the migration rule and mechanism of radon and its daughters was studied

and significant results were obtained: (1) Under laboratory conditions

the vertical component of migration of radon and its daughters was much greater than the horizontal component

the former was over 90% and the latter was less than 10%. (2) Despite the very big specific gravity of radon and its daughters

the descending component of migration was less than 45%

while the ascending component was more than 45%. (3) After a -particles (emitted from radon and its daughters) being slowed down

4He combined with the radon and its daughters to form clusters. When the density of the cluster was less than that of the air the self-ascending would occur.