Press release from RIKEN Nishina Center for Accelerator-Based Science

The most unambiguous data to date on the elusive 113th atomic element has been obtained by researchers at the RIKEN Nishina Center for Accelerator-based Science (RNC). A chain of six consecutive alpha decays, produced in experiments at the RIKEN Radioisotope Beam Factory (RIBF), conclusively identifies the element through connections to well-known daughter nuclides. The groundbreaking result, reported in the Journal of Physical Society of Japan, sets the stage for Japan to claim naming rights for the element.

Steps in chain of decays from element 113 to mendelevium-254
The search for superheavy elements is a difficult and painstaking process. Such elements do not occur in nature and must be produced through experiments involving nuclear reactors or particle accelerators, via processes of nuclear fusion or neutron absorption. Since the first such element was discovered in 1940, the United States, Russia and Germany have competed to synthesize more of them. Elements 93 to 103 were discovered by the Americans, elements 104 to 106 by the Russians and the Americans, elements 107 to 112 by the Germans, and the two most recently named elements, 114 and 116, by cooperative work of the Russians and Americans.

With their latest findings, associate chief scientist Kosuke Morita and his team at the RNC are set follow in these footsteps and make Japan the first country in Asia to name an atomic element. For many years Morita's team has conducted experiments at the RIKEN Linear Accelerator Facility in Wako, near Tokyo, in search of the element, using a custom-built gas-filled recoil ion separator (GARIS) coupled to a position-sensitive semiconductor detector to identify reaction products. On August 12th those experiments bore fruit: zinc ions travelling at 10% the speed of light collided with a thin bismuth layer to produce a very heavy ion followed by a chain of six consecutive alpha decays identified as products of an isotope of the 113th element (Figure 1).

While the team also detected element 113 in experiments conducted in 2004 and 2005, earlier results identified only four decay events followed by the spontaneous fission of dubnium-262 (element 105). In addition to spontaneous fission, the isotope dubnium-262 is known to also decay via alpha decay, but this was not observed, and naming rights were not granted since the final products were not well known nuclides at the time. The decay chain detected in the latest experiments, however, takes the alternative alpha decay route, with data indicating that Dubnium decayed into lawrencium-258 (element 103) and finally into mendelevium-254 (element 101). The decay of dubnium-262 to lawrencium-258 is well known and provides unambiguous proof that element 113 is the origin of the chain.

Combined with their earlier experimental results, the team's groundbreaking discovery of the six-step alpha decay chain promises to clinch their claim to naming rights for the 113th element.

"For over 9 years, we have been searching for data conclusively identifying element 113, and now that at last we have it, it feels like a great weight has been lifted from our shoulders," Morita said. "I would like to thank all the researchers and staff involved in this momentous result, who persevered with the belief that one day, 113 would be ours. For our next challenge, we look to the uncharted territory of element 119 and beyond."

The 2007 Ig Nobel Chemistry prize winner was Mayu Yamamoto (International Medical Centre of Japan) for developing a way to extract vanillin (vanilla fragrance and flavour) from cow dung. The 2007 Ig Nobel Prize winners were announced 5th October 2007 and prizes prizes awarded at Harvard in America. To celebrate, a local ice cream bar put on a tasting session of a new flavour, Yum-A-Moto Vanilla Twist, concocted in honour of the 2007 Ig Nobel Chemistry Prize winner Mayu Yamamoto. The mind boggles.

The 2006 Ig Nobel Chemistry prize winner was Antonio Mulet, José Javier Benedito and José Bon of the University of Valencia, Spain, and Carmen Rosselló of the University of Illes Balears, in Palma de Mallorca, Spain, for their study "Ultrasonic Velocity in Cheddar Cheese as Affected by Temperature".

The 2006 Ig Noble prize for chemistry has been announced and was awarded to Spanish researchers Antonio Mulet, José Javier Benedito and José Bon (University of Valencia), and Carmen Rosselló (University of Illes Balears), for their outstanding research: "Ultrasonic Velocity in Cheddar Cheese as Affected by Temperature." published in the Journal of Food Science.1

The Ig Noble prizes are administered by the publishers of the Annals of Improbable Research magazine. It's not always clear to me that the Chemistry Ig Noble prizes seem more related to other areas, and some non-chemistry prizes look as though the work was chemical, but never mind. For the record, here are a few of the more recent awards.

2005

Edward Cussler and Brian Gettelfinger (University of Minnesota and the University of Wisconsin), for their work that finally settled the longstanding scientific question: can people swim faster in syrup or in water? See "Will Humans Swim Faster or Slower in Syrup?".2

2004

The Coca-Cola Company of Great Britain, for using advanced technology to convert ordinary tap water into Dasani, a transparent form of water, which for "precautionary reasons" was withdrawn form the market in the UK (it seems the Dasani contained the carcinogenic bromate - the UK Food Standards Agency advice was that while Dasani contained illegal levels of bromate, it did not present an immediate risk to the public). See various press stories including:

1. The Telegraph
2. The Guardian

2003

Yukio Hirose of Kanazawa University in Japan, for his chemical investigation of a bronze statue in the city of Kanazawa that fails to attract pigeons.

2002

Theodore Gray of Wolfram Research (Champaign, Illinois, USA) for gathering elements of the periodic table and assembling them into a periodic table table.

• 1. Ultrasonic Velocity in Cheddar Cheese as Affected by Temperature,
  Mulet, A., Benedito J., Bon J., and Rossello C.
  , Journal of Food Science, 11/1999, Volume 64, Issue 6, p.1038 - 1041, (1999)
  
• 2. Will humans swim faster or slower in syrup?,
  Gettelfinger, Brian, and Cussler E. L.
  , AIChE Journal, 11/2004, Volume 50, Issue 11, p.2646 - 2647, (2004)