Saturday, March 12, 2011

Deceased--Simon van der Meer

Simon van der Meer
November 24th, 1925 to March 4th, 2011

"Simon van der Meer, Nobel Laureate, Dies at 85"


Kenneth Chang

March 11th, 2011

The New York Times

Simon van der Meer, who shared the Nobel Prize in Physics in 1984 for a technological advance that was crucial to the discovery of fundamental building blocks of the universe, died March 4 in Geneva. He was 85.

His death was announced by CERN, the particle physics laboratory in Switzerland where he worked for more than 30 years.

In the 1980s, physicists were looking to fill in missing elementary particles predicted by their so-called Standard Model, the suite of theories that has ruled particle physics for a generation and explains all the forces of nature except gravity. To find them, however, researchers needed collisions more energetic than what could be produced by particle accelerators.

Mr. van der Meer’s advance was finding a way to generate intense beams of a particular particle, antiprotons, that were needed for the experiments. By slamming antiprotons and protons together, physicists achieved higher-energy collisions that revealed constituents of the universe never before seen.

“It was a completely revolutionary technique that made something possible that was completely impossible without it,” said John Marriner, a senior scientist at the Fermi National Accelerator Laboratory, more commonly known as Fermilab, outside Chicago.

After coming up with the technique, Mr. van der Meer helped lead the team that applied it using an accelerator at CERN called the Super Proton Synchrotron.

In 1983, CERN reported that proton-antiproton collisions in the synchroton had created particles known as W and Z bosons, key components of the so-called weak force.

The weak force is one of the four fundamental forces of the universe, the others being gravity, electromagnetism and the strong force, which holds atomic nuclei together.

The weak force is of no consequence at the scale of everyday objects. But for subatomic particles, it is a major influence. For instance, the weak force enables the sun to shine by allowing hydrogen atoms to fuse together, releasing heat and light. The W and Z bosons convey the weak force in much the same way photons — particles of light — convey electromagnetism.

The next year, Mr. van der Meer and his CERN colleague Carlo Rubbia, an Italian physicist, were awarded the physics Nobel for “their decisive contributions to the large project, which led to the discovery of the field particles W and Z, communicators of weak interaction.”

Simon van der Meer was born Nov. 24, 1925, in The Hague, the Netherlands. After graduating with an engineering degree from the University of Technology in Delft, he worked on high-voltage equipment for electron microscopes at Philips Research Laboratory in Eindhoven.

In 1956, he joined CERN, developing methods to corral and guide various particles.

Beginning in the 1960s, Mr. van der Meer and others started working on a technique called stochastic cooling, which measures charged particles as they pass by and then applies an electric field to nudge them in the desired direction.

In a statement, Rolf-Dieter Heuer, director general of CERN, and Stephen Myers, director of accelerators and technology at the laboratory, said stochastic cooling was typical of Mr. van der Meer’s inventions: “deceptively simple at first sight, but to anyone who truly understands accelerators it was nothing less than a stroke of genius.”

For the weak force experiments, physicists needed high-speed collisions between a proton, a particle found in the nucleus of atoms, and its antimatter doppelganger, the antiproton.

Since protons exist in every atom, making beams of them is easy. But an antiproton is rare, and it annihilates the moment it touches a proton. Particle accelerators can create sprays of antiprotons with high-energy proton collisions, but the antiprotons fly out in different directions with not enough left for the experiments. With stochastic cooling, the spray of antiprotons could be shepherded into a tight beam.

The beam of antiprotons was then collided with a beam of protons traveling in the opposite direction. In the ensuing subatomic carnage, CERN physicists spotted clear signs of W and Z bosons.

Mr. van der Meer retired from CERN in 1990. He is survived by his wife of 44 years, Catherine van der Meer-Koopman; a daughter, Esther van der Meer; a son, Mathijs; a sister, Gay van der Meer; and a granddaughter.

Building on Mr. van der Meer’s work, Fermilab added stochastic cooling to its more powerful Tevatron collider, leading to the discovery in 1994 of the top quark, the final piece of matter in the Standard Model.

“That was a key technology,” Dr. Marriner said. “We copied his ideas.”

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