Passion for physics and photography

Alejandro Szanto Toledo helped train a generation of nuclear physicists in Brazil

Szanto de Toledo: skilled in instrumentation and carrying out experiments

Eduardo CesarSzanto de Toledo: skilled in instrumentation and carrying out experimentsEduardo Cesar

Shortly before Mardi Gras, 1964, the physicist Oscar Sala was performing maintenance on a Van de Graaff generator, the most advanced equipment at the time for accelerating particles to very high speeds, when a freshman visiting his laboratory at the University of São Paulo (USP) asked him if he could work there, on nuclear physics. “Show up Tuesday at 7am and you’re hired,” was Sala’s response to the young man who, at 19, would only start his undergraduate degree a few weeks later. “I showed up on the agreed-upon day and never left [the university],” recounted Alejandro Szanto de Toledo in an interview with colleagues at the USP Physics Institute in 2012, where he worked for over 50 years. Alex, as he was called by his friends, died in São Paulo on February 21, 2015 as a result of intestinal cancer. He was 69 and married to the physicist and professor Eloisa Madeira Szanto, with whom he had a daughter.

The same boldness that led him to approach Sala, a renowned physicist, allowed Szanto de Toledo to build a career that brought him international recognition in low-energy physics and allowed him to establish one of the few high-energy physics groups in Brazil. The son of a Hungarian father and a Spanish mother, Szanto de Toledo was born in Tangier, Morocco, and immigrated to Brazil as a child. He studied at the Lycée Pasteur in São Paulo and, in 1963, took the USP entry exams to study physics and electronics engineering. He worked towards degrees in both fields for three years, but then withdrew from the second one in order to focus on nuclear physics research with Sala, his advisor for both his master’s and PhD.

He was interested in instrumentation, and in his first months at the laboratory Szanto de Toledo identified some problems that hindered the operation of the Van de Graaff generator. “Since I was already presumptuous at the time, I told Sala: ‘Look, this is all wrong, you need to add a protection system’. And Sala replied: ‘So do it,'” he once recounted. His earnestness and skill in overcoming these challenges led Sala, a former FAPESP Scientific Director, to later entrust him with designing and building the equipment—the ion source—that would supply the particles used in the next-generation accelerator, the Pelletron, which was inaugurated in 1972 to carry out experiments that could not be done with the Van de Graaff.

It was in the Pelletron that Szanto de Toledo and his students carried out experiments that demonstrated that the collision of atomic nuclei does not always lead to their complete fusion because one of them could break apart before impact. These results corroborated the nuclear breakup hypothesis, proposed in the 1980s, and made the group known internationally. “This result is important for understanding what takes place inside stars and generated a whole line of research,” says physicist Jun Takahashi, of the University of Campinas (Unicamp), one of Szanto de Toledo’s disciples.

In the mid-1990s, Szanto de Toledo decided to embark on a new ​​research path. He sent three of his students, Takahashi, Marcelo Munhoz and Patrícia Facchini, to work at more powerful accelerators in the United States and they began their studies in high energy physics. This research later led them to participate in one of the experiments at the Large Hadron Collider (LHC). “One of Alex’s characteristics was his enthusiasm for physics,” says Munhoz, a professor at USP.

In December 2012, Szanto de Toledo, who was a member of the FAPESP Board of Trustees, revealed another of his passions: photography. He released the book Face a face: uma jornada pelos povos do mundo (Face to face: a journey through the people of the world), with 350 pictures of people of different ethnicities, the result of his travels to the remotest parts of the planet. Before his death he was working on a new book of portraits of children, to be published soon.