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Could vacuum physics be revealed by laser-driven microbubble?

Date:
July 10, 2019
Source:
Osaka University
Summary:
Scientists have discovered a novel mechanism which they refer to as microbubble implosion (MBI) in 2018. In this study, the group confirmed that during MBI, an ultrahigh electrostatic field close to the Schwinger field could be achieved because micron-sized bubbles embedded in a solid hydride target implode to have nanometer-sized diameters upon ionization.
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A "vacuum" is generally thought to be nothing but empty space. But in fact, a vacuum is filled with "virtual particle-antiparticle pairs" of electrons and positrons that are continuously created and annihilated in unimaginably short time-scales.

The quest for a better understanding of vacuum physics will lead to the elucidation of fundamental questions in modern physics, which is integral in unravelling the mysteries of space exploration such as the Big Bang. However, to forcibly separate the virtual pairs using a laser's electric field and cause them to appear not as virtual particles but real particles, the laser intensity required would be ten million times higher than what today's laser technology is capable of. This field intensity is the so-called "Schwinger limit," named a half century ago after the American Nobel laureate, Julian Schwinger.

Scientists at Osaka University discovered a novel mechanism which they refer to as microbubble implosion (MBI) in 2018. In MBI, super-high energy hydrogen ions (relativistic protons) are emitted at the moment when bubbles shrink to atomic size through the irradiation of hydrides with micron-sized spherical bubbles by ultraintense, ultrashort laser pulses.

In this study, the group led by Masakatsu Murakami confirmed that during MBI, an ultrahigh electrostatic field close to the Schwinger field could be achieved because micron-sized bubbles embedded in a solid hydride target implode to have nanometer-sized diameters upon ionization.

From the 3D simulations carried out at the Osaka University Institute of Laser Engineering, they also found that the density during the maximum compression of the bubble reaches several hundred thousand to one million times solid density. At this density, something no larger than a lump sugar would weigh a few hundred kilograms. The energy density at the bubble center was found to be about one million times higher than that at the sun. These astonishing numbers have been thought to be impossible to achieve on Earth. Their research results were published in Physics of Plasmas.


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Materials provided by Osaka University. Note: Content may be edited for style and length.


Journal Reference:

  1. M. Murakami, A. Arefiev, M. A. Zosa, J. K. Koga, Y. Nakamiya. Relativistic proton emission from ultrahigh-energy-density nanosphere generated by microbubble implosion. Physics of Plasmas, 2019; 26 (4): 043112 DOI: 10.1063/1.5093043

Cite This Page:

Osaka University. "Could vacuum physics be revealed by laser-driven microbubble?." ScienceDaily. ScienceDaily, 10 July 2019. <www.sciencedaily.com/releases/2019/07/190710103223.htm>.
Osaka University. (2019, July 10). Could vacuum physics be revealed by laser-driven microbubble?. ScienceDaily. Retrieved June 12, 2024 from www.sciencedaily.com/releases/2019/07/190710103223.htm
Osaka University. "Could vacuum physics be revealed by laser-driven microbubble?." ScienceDaily. www.sciencedaily.com/releases/2019/07/190710103223.htm (accessed June 12, 2024).

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