The electric furnace spectrum of titanium in the ultraviolet : A.S. King. (Astrophys. Jour., April, 1924.)
✍ Scribed by G.F.S.
- Book ID
- 104124962
- Publisher
- Elsevier Science
- Year
- 1924
- Tongue
- English
- Weight
- 90 KB
- Volume
- 198
- Category
- Article
- ISSN
- 0016-0032
No coin nor oath required. For personal study only.
✦ Synopsis
in the " Snstitut f iir Radiumf orschung,"
Vienna, have worked with such success upon this problem that it is now known that no less than fourteen elements liberate H-particles when under bombardment by z-particles. Alpha particles from radium C travel through helium and strike the element under investigation.
A zinc sulphide screen is located in the experimental vessel so that the line joining it to the bombarded element forms approximately a right angle with the path of the a-particles.
Owing to the impact of these particles, atoms of the element may be broken up and fragments may pass off sideways and cause scintillations where they strike the screen. Several precautions were taken to secure results.
A microscope of high light-gathering power was used to observe the screen.
Special shapes were given to the radium C source as well as to the element bombarded in order to get a maximum output of atomic fragments and moreover helium gas was employed because, when a stream of a-particles in this gas falls on a target, " the range of a-particles scattered under 90" is nil." Thus whatever particles were detected at the screen they could not be identified with a-particles scattered by the target, and, furthermore, atomic fragments of short range could be sought.
The helium was provided by the Bureau of Mines, Washington. Two very weighty results have been attained by the method just described: (I) " Carbon, examined as paraffin, as very pure graphite, and finally as diamond powder, gives off H-particles of about 6-cm. range. Their number, which has not yet been accurately determined, is of the order 200 per IO? of the a-particles producing the disintegration," and (2) " other experiments recently made seem to prove that oxygen is also disintegrable and gives off a-particles of 9-cm. range in the forward direction.
If this result is confirmed by further experiments now proceeding, it would furnish the first example of a-particles as a product of artificial disintegration."
We have clearly come a long distance since the day when Bancroft delivered1 his address before the A. A. A.