03.05.2008
РОССИЙСКАЯ АКАДЕМИЯ НАУК

УРАЛЬСКОЕ ОТДЕЛЕНИЕ

ИНСТИТУТ ХИМИИ TBEPДОГО ТЕЛА
   
| | | | |
| | | | | |
 03.05.2008   Карта сайта     Language По-русски По-английски
Новые материалы
Экология
Электротехника и обработка материалов
Медицина
Статистика публикаций


03.05.2008



Heaviest element claim criticised



02 May 2008



Scientists claiming to have discovered the super-heavy element 122 have had their research dismissed by physicists who say their measurements are suspect. 


A collaboration of researchers led by Amnon Marinov at the Hebrew University of Jerusalem say their mass spectrometer has detected something with an atomic mass around 292, hiding in piles of purified thorium. They think this is most likely a nucleus with 122 protons and 170 neutrons. The research is described in an article posted to the internet pre-print server, arXiv, but has not been peer reviewed. 


If substantiated, the sighting would dramatically extend the limits of the periodic table, which currently stops at element 118. But physicists contacted by Chemistry World were critical of the team's findings. 'I doubt this will survive peer review: they will need more support and better evidence for their claims,' says nuclear physicist Rolf-Dietmar Herzberg, of the University of Liverpool, UK. 


Contested claim


Among the criticisms levelled at Marinov's team are that their equipment may have spotted combinations of ions with the same mass as element 122, though Marinov says he is sure there was no such contamination. 


Andreas Türler, who investigates superheavy elements at the Technical University of Munich, Germany, says the team have likely misused their mass spectrometer. 'We use an identical model, and it is not intended as an isotope separator - rather, to measure ultralow concentrations [of known elements],' he explains. 'Introducing highly concentrated solutions as Marinov's team did may cause all sorts of effects that are beyond the control of the operator. I seriously doubt that a reliable measurement was obtained under the conditions of the reported experiment.' 


In response to that criticism, Marinov says his team calibrated their instrument to make sure that the thorium solution they injected was not so concentrated that it disrupted their readings.


But both Herzberg and Türler also point out that Marinov's identification of unbibium (122) is based on the assumption that the element behaves in a similar chemical fashion to thorium - doubtful, if relativistic effects affect the element's chemistry. 


Too stable?


Perhaps the most surprising aspect of the 122 claim is that the element, the researchers calculate, has a half-life of 108 years - which is why it could be found lying around in thorium. Super-heavy elements are usually too unstable to exist for more than a few fractions of a second, so have to be made, fleetingly, by smashing nuclei together. Marinov thinks that element 122 is stable because its nucleus is 'hyper-deformed' from the usual spherical shape, preventing it from splitting apart. He has reported the discovery of long-lived isomers of hyper-deformed nuclei before, Türler says, but none of the claims have been verified by other experiments.  


Researchers at Lawrence Livermore National Laboratory, California, who helped confirm the detection of element 118 in 2006, told Chemistry World they were too busy to check through Marinov's research.  


'The popular vote is one of ridicule and I cannot fault that,' Herzberg sums up.  


Marinov says he has submitted the article to the journals Nature and Nature Physics, but both turned it down without sending it for peer review. 'I am not changing the article and hope to get it published in another journal.' 


Richard Van Noorden


 


Enjoy this story? Spread the word using the 'tools' menu on the left.



References


A Marinov et alarXiv:0804.3869 (pre-print)



Дизайн и программирование N-Studio 
А Б В Г Д Е Ё Ж З И Й К Л М Н О П Р С Т У Ф Х Ц Ч Ш Щ Ъ Ы Ь Э Ю Я
  • Chen Wev   honorary member of ISSC science council

  • Harton Vladislav Vadim  honorary member of ISSC science council

  • Lichtenstain Alexandr Iosif  honorary member of ISSC science council

  • Novikov Dimirtii Leonid  honorary member of ISSC science council

  • Yakushev Mikhail Vasilii  honorary member of ISSC science council

  • © 2004-2024 ИХТТ УрО РАН
    беременность, мода, красота, здоровье, диеты, женский журнал, здоровье детей, здоровье ребенка, красота и здоровье, жизнь и здоровье, секреты красоты, воспитание ребенка рождение ребенка,пол ребенка,воспитание ребенка,ребенок дошкольного возраста, дети дошкольного возраста,грудной ребенок,обучение ребенка,родить ребенка,загадки для детей,здоровье ребенка,зачатие ребенка,второй ребенок,определение пола ребенка,будущий ребенок медицина, клиники и больницы, болезни, врач, лечение, доктор, наркология, спид, вич, алкоголизм православные знакомства, православный сайт творчeства, православные рассказы, плохие мысли, православные психологи рождение ребенка,пол ребенка,воспитание ребенка,ребенок дошкольного возраста, дети дошкольного возраста,грудной ребенок,обучение ребенка,родить ребенка,загадки для детей,здоровье ребенка,зачатие ребенка,второй ребенок,определение пола ребенка,будущий ребенок