Atomic Properties of Cf
- Atomic Number of Cf
- 98
- Atomic Mass of Cf
- 251.0000 u
- Electron Configuration
- [Rn] 5f10 7s2
- Electronegativity
- 1.30
- Block
- f-block
- Group
- —
- Period
- 7
Stanley Thompson, Kenneth Street Jr., Albert Ghiorso, and Glenn Seaborg produced californium at Berkeley in 1950 by bombarding curium with alpha particles. Its name honors both California and the University of California. Only tiny quantities have ever been made, chiefly through long reactor irradiations.
Californium-252 undergoes alpha decay and spontaneous fission. The fission events release an intense stream, not merely a strong burst of neutrons. Compact sealed sources have supported reactor startup instrumentation, neutron activation analysis, moisture and material gauges, and selected well-logging or inspection tasks. Neutron methods can reveal nuclei and structures that X-rays address differently. Each use depends on source encapsulation, distance, timing, detectors, and shielding.
The phrase help start up reactors safely needs precision. A californium source supplies neutrons that make reactor instrumentation responsive during startup; it does not independently initiate or control the power rise. Operators and engineered reactor systems perform that work.
Californium-251 is the longest-lived common reference isotope at roughly 900 years, while californium-252 has a half-life near 2.65 years. Strong neutron and gamma fields, contamination risk, cost, and limited production keep applications specialized. There is no general consumer use.
This Corebound switch is powerful because the source is small and predictable, not because it is casual. A carefully characterized isotope can probe material or verify a detector from inside layers of engineering control. Every useful neutron is paired with planning for exposure, transport, storage, and eventual disposal.