Featured Research

from universities, journals, and other organizations

Measurement at Big Bang conditions confirms lithium problem

Date:
August 27, 2014
Source:
Helmholtz-Zentrum Dresden-Rossendorf
Summary:
The field of astrophysics has a stubborn problem and it's called lithium. The quantities of lithium predicted to have resulted from the Big Bang are not actually present in stars. But the calculations are correct -- a fact which has now been confirmed for the first time.

Michael Anders beside the LUNA accelerator.
Credit: HZDR/M. Anders

The field of astrophysics has a stubborn problem and it's called lithium. The quantities of lithium predicted to have resulted from the Big Bang are not actually present in stars. But the calculations are correct -- a fact which has now been confirmed for the first time in experiments conducted at the underground laboratory in the Gran Sasso mountain in Italy. As part of an international team, researchers from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) studied how much lithium forms under Big Bang conditions.

Lithium, aside from hydrogen and helium, is one of the three elements that are created before the first stars form. These three elements were -- according to the theory -- already created early on, through what is known as "primordial nucleosynthesis." That means that when the universe was only a few minutes old, neutrons and protons merged to form the nuclei of the these elements. At the Laboratory for Underground Nuclear Astrophysics (LUNA), the nucleosynthesis of lithium has now been reproduced by an international team of scientists. Michael Anders, who earned his doctorate in the last year at TU Dresden and HZDR on this very topic, took a leading role on the team. Within the framework of a project that was funded by the German Research Foundation, he was supervised by Dr. Daniel Bemmerer, group leader at HZDR.

In the Italian underground laboratory, the scientists fired helium nuclei at heavy hydrogen (known as deuterium) in order to reach energies similar to those just after the Big Bang. The idea was to measure how much lithium forms under similar conditions to those during the early stages of the universe. The result of the experiment: the data confirmed the theoretical predictions, which are incompatible with the observed lithium concentrations found in the universe.

"For the first time, we could actually study the lithium-6 production in one part of the Big Bang energy range with our experiment," explains Daniel Bemmerer. Lithium-6 (three neutrons, three protons) is one of the element's two stable isotopes. The formation of lithium-7, which possesses an additional neutron, was studied in 2006 by Bemmerer at LUNA.

With these new results, what is known as the "lithium problem" remains a hard nut to crack: on the one hand, now all laboratory results of the astrophysicists suggest that the theory of primordial nucleosynthesis is correct. On the other hand, many observations of astronomers show that the oldest stars in our Milky Way contain only half as much lithium-7 as predicted. Sensational reports by Swedish researchers, who discovered clearly more lithium-6 in such stars than predicted, must also likely be checked again based on the new LUNA data. Bemmerer says, "Should unusual lithium concentrations be observed in the future, we know, thanks to the new measurements, that it cannot be due to the primordial nucleosynthesis."

Further research will soon be carried out in a new underground laboratory in Dresden.

What was important for the studies was the special location of LUNA: in the mountainous Gran Sasso d'Italia, 1400 meters of solid rock keep the disturbance from cosmic radiation at bay. The experimental setup is additionally enveloped in a lead shell. Only with such good shielding can the rare interactions between the nuclei be precisely determined. But within the next year, similar research will also be possible in Dresden. TU Dresden and HZDR will put the accelerator laboratory "Felsenkeller" into operation. Although the solid rock shielding from natural radiation in this former brewery cellar is only forty-five meters, it is already sufficient for many measurements. The new laboratory also possesses a particle accelerator that is more than twelve times as strong: "There we can expand our experiments and study the formation of elements at high energy ranges," says Bemmerer.

Lithium ist neben Wasserstoff und Helium eines der drei Elemente, die nicht erst innerhalb von Sternen erzeugt werden. Stattdessen -- so die Theorie -- sind sie schon früh durch die "primordiale Nukleosynthese" entstanden. Das heißt: Im nur wenige Minuten alten Universum haben sich Neutronen und Protonen zu den Kernen der ersten drei Elemente verbunden. Am Laboratory for Underground Nuclear Astrophysics (LUNA) wurde die Kernentstehung von Lithium nun von einem internationalen Forscherteam nachgestellt. Eine führende Rolle im Team nahm Michael Anders ein, der im vergangenen Jahr an der TU Dresden und am HZDR zu dem Thema promoviert hat. Im Rahmen eines von der Deutschen Forschungsgemeinschaft geförderten Projekts wurde er dabei von Dr. Daniel Bemmerer, Gruppenleiter am HZDR, betreut.


Story Source:

The above story is based on materials provided by Helmholtz-Zentrum Dresden-Rossendorf. Note: Materials may be edited for content and length.


Cite This Page:

Helmholtz-Zentrum Dresden-Rossendorf. "Measurement at Big Bang conditions confirms lithium problem." ScienceDaily. ScienceDaily, 27 August 2014. <www.sciencedaily.com/releases/2014/08/140827100222.htm>.
Helmholtz-Zentrum Dresden-Rossendorf. (2014, August 27). Measurement at Big Bang conditions confirms lithium problem. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2014/08/140827100222.htm
Helmholtz-Zentrum Dresden-Rossendorf. "Measurement at Big Bang conditions confirms lithium problem." ScienceDaily. www.sciencedaily.com/releases/2014/08/140827100222.htm (accessed September 22, 2014).

Share This



More Space & Time News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's MAVEN Spacecraft Has Finally Reached Mars

NASA's MAVEN Spacecraft Has Finally Reached Mars

Newsy (Sep. 22, 2014) — After a 10-month voyage through space, NASA's MAVEN spacecraft is now orbiting the Red Planet. Video provided by Newsy
Powered by NewsLook.com
Raw: SpaceX Rocket Carries 3-D Printer to Space

Raw: SpaceX Rocket Carries 3-D Printer to Space

AP (Sep. 22, 2014) — A SpaceX Rocket launched from Cape Canaveral, carrying a custom-built 3-D printer into space. NASA envisions astronauts one day using the printer to make their own spare parts. (Sept. 22) Video provided by AP
Powered by NewsLook.com
SpaceX Cargo Ship Blasts Off Toward Space Station

SpaceX Cargo Ship Blasts Off Toward Space Station

AFP (Sep. 21, 2014) — SpaceX's unmanned Dragon cargo ship blasts off toward the International Space Station, carrying a load of supplies and science experiments for the astronauts living there. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
NASA's MAVEN To Study Martian Atmosphere

NASA's MAVEN To Study Martian Atmosphere

Newsy (Sep. 21, 2014) — NASA's Maven will soon give information that could explain what happened to Mars' atmosphere. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins