In Romania, the most powerful laser beam in the world – 03/29/2024 at 12:56

“Ready? Signal sent!” : In the control room of a research center in Romania, Antonia Toma, shooting director, activates the world’s most powerful laser, with revolutionary promises from health to space.

The numbers are staggering: the system is capable of peaking at 10 petawatts (10 to 15 watts of power) for ultra-short times on the order of femtoseconds (one billionth of a second).

Against a wall of screens displaying light beams, the 29-year-old engineer checks a series of indicators before starting a countdown.

The rate of these shots conducted at targets located in experimental chambers is currently very high – 30 to 40 shots per day.

During a press visit to the site near the capital Bucharest this week, she told AFP that it was “stressful but very rewarding” work, given that teams of researchers come from around the world to test these unique instruments.

– Technology gem –

On the other side of the glass, long rows of red and black boxes hold two laser chains.

Inside is a technical feat: titanium sapphire crystals, which are excited under the effect of optical pumps, beams, hundreds of mirrors of all sizes, gold-coated diffraction gratings. ..

Achieving this extraordinary level of performance took “several million euros, 450 tons of equipment” and careful installation time, explains Franck Leibrich, who is responsible for laser activities for the French group Thales, which operates the system.

Equipped with anti-vibration slabs, the building, which required an investment of 320 million euros financed mainly by the EU, is the pride of Romania. However, the construction of the gamma ray production unit has encountered problems and will not be completed until 2026.

– “One giant step” –

Walking around the large room with its immaculate white floor, Gerard Mauro, the 2018 Nobel laureate in physics, says he is “deeply moved” by this “incredible odyssey”, from the United States where he spent thirty years to fruition in Europe. Projects born in the 2000s within the European infrastructure ELI (Extreme Light Infrastructure).

“We start with a tiny bright seed of very low energy, which will expand millions and millions of times,” he explains, with the air of a child amazed that despite his 79 years and his white hair he has “taken giant strides” and acquired “extraordinary powers”. .

The technique, called “chirped pulse amplification” (CPA), was developed in the mid-1980s by Canadian researcher Donna Strickland and co-Nobel laureate, then her student. It involves laser pulse stretching, to expand and then contract. that

In addition to their contributions to the physics of vacuum or black holes, the work of the two scientists has made it possible to operate on millions of people suffering from myopia or cataracts.

And the latest achievements will allow us to go further, assures Professor Mauro, especially in the medical field. “We will use these ultra-intense pulses to create a more compact and less expensive particle accelerator” to destroy cancer cells, he asserts.

– an army of “soldiers” –

Other possible applications include treating nuclear waste by shortening its radioactivity or “cleaning up space” covered by countless debris – “the equivalent of four Eiffel Towers, so 28,000 tonnes”.

In this case, “a laser can be used to remove this debris and produce a kind of rocket effect that is able to remove it.”

Lasers – whose basic principles were described by Einstein in 1916 – have established themselves in our daily lives, from CDs to supermarket barcode readers, or even in industry where these precision tools are used in welding or cutting.

It has one color (red, green, blue, etc.) while ordinary light in which we bathe is made up of many colors. All light waves go in the same direction and form a narrow beam.

Photons are identical, making the light produced by a lamp “unlike soldiers marching in order, marathon runners,” Gerard Mauro graphically describes.

He is convinced: after the triumph of the electron in the 20th century, the 21st century will be that of the laser.

Moreover, other countries – France, China or the United States – are in the race to produce more powerful lasers.