Amnon Marinov

On April 24, 2008, a group led by Marinov at Hebrew University of Jerusalem claimed to have found single atoms of unbibium-292 in natural thorium deposits at an abundance of 10⁻¹¹ to 10⁻¹² relative to thorium.^[1] This was the first time in sixty-nine years that a new element had been claimed to be discovered in nature, after Marguerite Perey's 1939 discovery of francium.^[a] The claim of Marinov et al. was criticized by a part of the scientific community, and Marinov said he submitted the article to the journals Nature and Nature Physics but both turned it down without sending it for peer review.^[2] The unbibium-292 atoms were claimed to be superdeformed or hyperdeformed nuclear isomers, with a half-life of at least 10⁸ years.^[3]

A criticism of the technique, previously used in purportedly identifying lighter thorium isotopes by mass spectrometry,^[4] was published in Physical Review C in 2008.^[5] A rebuttal by the Marinov group was published in Physical Review C after the published comment.^[6]

A repeat of the thorium experiment using the superior method of accelerator mass spectrometry (AMS) failed to confirm the results, despite a 100-fold better sensitivity.^[7] This result throws considerable doubt on the results of the Marinov collaboration with regards to their claims of long-lived isotopes of thorium,^[4] roentgenium^[8] and unbibium.^[1] It is still possible that traces of unbibium might exist in some thorium samples, though given current understanding of superheavy elements, this is very unlikely.^[3]

Amnon Marinov lived in Jerusalem, Israel with his wife Rachel; they have four children and six grandchildren. His father, Haim Marinov (1904–2001), was the deputy mayor of Jerusalem from 1964 until 1973. His father-in-law, Ya'akov Maimon (1902–1977), was the inventor of Hebrew stenography and received the Israel Prize in 1976 for his lifelong voluntary work teaching Hebrew to new immigrants all over the country.^[9] Amnon Marinov died on December 7, 2011.