Por sua liderança orientada para objetivos,
Por seu entusiasmo e energia sem fim,
Por sua criatividade estimulante,
Por fornecer uma fonte de luz de classe mundial para inúmeras gerações de cientistas de raios-X,
Nosso muito obrigado!



Dear Friends of Ricardo

With this symposium we celebrate Ricardo’s extraordinary contribution to the rejuvenation of Brazilian x-ray science during the past 30 years. When I came to Brazil in the late 80s to give seminars on synchrotron radiation at several universities, I was shown many x-ray generators, which however did not work anymore because the bulbs had burned out and there was no money available for replacements. Brazil had a long history of x-ray science and crystallography, which now came to a stand still for lack of funding. Many of Brazilian scientists worked at the light source ACO in France under the leadership of Aldo Craievich. Something had to be done. Talks started to consider building a national laboratory with a synchrotron light source especially under Drs. Muniz and Roberto Lobo at CBPF in Rio de Janeiro, who worked to form a project group. During my next visit I was introduced to a few people of the group, which included Ricardo. Quickly I sense how serious and eager they were and so I invited them to come for three months to Stanford to get introduced into synchrotron source theory and design. This was approved and soon Ricardo came with a few staff members. They started immediately with great energy except of one, who preferred to play football to synchrotron physics and technology. Here, Ricardo showed his goal-oriented leadership skills and the guy got a free airline ticked back home after only one week. After all, which Brazilian would go to California to improve his football skills.

After returning back to Brazil, they applied what they had learned and designed their own Brazilian storage ring, which is now LNLS. The first technical challenge was to get a linac working. Ricardo got somehow a SLAC linac section and together with whatever they could find they put together a functioning linac, albeit with somewhat unconventional components. Who needs a fancy cooling system when you can use a cooler from an old Chevy. I happened to be in Brazil when they started linac commissioning. How do you know there is a beam? Well, you could look for synchrotron radiation, but you need a mirror to deflect the light away from the electron beam. There was no mirror and the stores in the city were closed at this hour, when Ricardo mentioned ..”I know where there is a mirror”….”in the ladies bathroom…”. A few minutes later he came back with a big mirror under his arm. Soon it was installed and commissioning could start in earnest. After some time of adjustments there was a bright light…. which was, as Cylon noted, Cherenkov Radiation, indicating, there was a multi-MeV electron beam, the first in the Southern Hemisphere, ever. Quite some achievement!

The next step was to design and build some prototypes for the storage ring. Cylon Gonzalves da Silva, the project director, spent most of his time on airplanes and could pry some funding out of bureaucrats in Brasilia. Probably, they gave him some funds just to get rid of him. Practical activities could start. Persistence works! Already 2000 years ago. You can read on this approach in the Bible.

For the magnets, solid iron could not be considered because of quality considerations, but laminations must be punched for which you need a big press and punching dies, which are very expensive. Ricardo had a solution by buying a used laser cutter. This solution is slow and labor intensive, but I think it could keep pace with the funding flow from Brasilia. Soon, Ricardo and Regis got the cutter to work and they could punch all the different shapes of laminations they needed to build the prototypes. These few examples show how unconventional Ricardo was. His moto: If there is no fundamental physical law against it, then any problem can be solved.

The storage ring was finally finished and ready for commissioning. Injection was very hard, because there was no synchrotron, but only a low energy linac to inject directly into the storage ring. Finally, they accomplished to store an electron beam and produce synchrotron radiation. The first in the Southern Hemisphere, again, ever and the ability to do X-ray physics again in Brazil was restored. Brazilian researchers under the leadership of Aldo Craievich, who were experimenting at ACO in France, came back to LNLS to set up new beam lines and experimental stations.

Since injection was hard and took a long time, Ricardo thought about a solution and designed a small synchrotron between linac and storage ring. Always looking for new technologies, Ricardo decided to use a solid state Rf-amplifier, which was at that time very new and was used only at Soleil in France. The synchrotron project worked well and allowed quick filling with beam of the storage ring. This completed the first synchrotron light source in the Southern Hemisphere, thus restoring x-ray research capabilities in Brazil and beyond. The interest and growth in now much broader research applications during the operation of LNLS speak for themselves.

It didn’t take long before people started to think about the next step. Ricardo wanted to contribute to climate change. When they got the land, director Cylon and he argued for the need of a large enough area for some future expansion. It was not clear what that expansion would be or when funding could be secured for such a project. So, the best median term solution was to just plant trees.

Ricardo may have been stimulated by the green of the trees to think about the possibility of a “Green Ring”, a synchrotron light source that would demand the least energy. Replacing the magnets by permanent magnets comes to mind. Together with Regis, they designed such magnets and actually built a prototype which met the required quality. Unfortunately, the world market of high-quality permanent magnet material was not and still isn’t ready for Ricardo.

That, of course, did not stop people thinking about an expansion. The LNLS worked superbly, the user community grew steadily but because of the small size and energy LNLS the ever-growing user groups stretched the capabilities of the facility more and more. How about a new low emittance 3 GeV ring? After all, they already had the site, all that was needed, was the permission from Campinas to cut some trees. You all know how that went. “ No, you can’t cut any trees for whatever purpose”. Yet, the Campinas authorities had come to appreciate the contribution LNLS made to the community and offered a new site…. without trees… next to the lab where Sirius is located now.

The new director, Antonio Jose Roque da Silva, was all enthusiastic and supportive about the prospect of a high brightness light source. Serious design work started with an already existing experienced staff. Again, with the success of LNLS, the government was now more open to the increasing frequency of visits by Jose in Brasilia. A MAC was formed and reviewed the first design. Knowing Ricardo’s penchant for demanding technologies, the MAC encouraged to push the design to higher brightness, commensurate with the size of the ring. That was all, Ricardo needed, especially, since the director Jose pushed in the same direction. The design of the light source got a complete overhaul and did not miss any available new technology known in the field and useful for the design of SIRIUS. Together with his wife Liu Lin and her staff they developed new low emittance lattices to match the highest brightness ring designs in the world.

By the next MAC meeting, a lattice with an emittance of 270pm was proposed which has a comfortable dynamic aperture. There is one problem with low emittance lattices: they require low field bending magnets, which means you can get hard x-rays only from insertion devices, not from bending magnets. Well, in Sirius, this is solved by high field inserts in the middle of bending magnets. In Sirius these inserts make all bends hard x-ray sources while actually reducing the beam emittance, a double whammy. But that is not all. Still thinking “greenish”, Ricardo pursued the idea of NEG pumping, which would allow much smaller vacuum chamber diameters and thereby much smaller magnet apertures, smaller magnets, lower energy consumption, reduced power supplies and other beneficial design choices. So far, NEG pumping has never been used for light sources except in special vacuum chambers in insertion devices. After getting the license from CERN, they developed techniques to deposit the NEG material into long small diameter tubes. One has to realize the great risk Ricardo was taking, because the design of many more ring components depended on the efficacy of the NEG pumping in small tubes. Ricardo, though, was never afraid of taking risks if he didn’t see any fundamental limits and that’s why he won so often, because he was self-confident enough to work out a solution.

The whole SIRIUS project was completed in record time and before the end of last year first stored beam was achieved and first light extracted to allow the first experiment from the new, most advanced synchrotron light source in the world. Ricardo left a most experienced crew to now continue the optimization of the Sirius storage ring and commissioning of the beam lines.

In a span of only one generation, Ricardo, with the support of directors, competent staff, users and support of government authorities, has made a major contribution to bring the long term Brazilian history of x-ray physics from a desperate state of burned out x-ray lamps to the successful completion of the most brilliant light source in the world. Generations of Brazilian and international scientists are eagerly waiting at the doors to start their experiments. An achievement anyone of us would be proud of.

I dare to speculate, however, that Ricardo left a last challenge to his staff. After completion of full commissioning and optimization of Sirius, staff will have a perfect machine and can pursue the maximum brightness for spatially coherent x-rays, a feat that has never been achieved in the world. Remember, after the first MAC meeting, Liu Lin and her staff developed several low emittance lattices, but proposed finally the safest one with the maximum dynamic aperture. If I am not totally wrong, there was at least one lattice with an emittance of less than 100pm, but only a marginal dynamic aperture, which could not be proposed to a Machine Advisory Committee. A ring with the circumference of Sirius should allow such a low emittance without the use of damping wigglers. Now, staff can use some time to revive such lattice solutions or come up with new ones and work out at least a marginal dynamic aperture and test it out during machine physics. You have no MAC anymore to convince and you have a perfect machine that you understand in detail…..and, best of all it will not cost any new governmental funds. Imagine a SIRIUS light source with an emittance of 100pm or less and, with full coupling half of that, would be the first spatially coherent light source in the world, a dream of experimenters I have heard all my life. It would be a fantastic conclusion for a whole cycle of technological development while leaving behind an experienced staff to continue innovation into the future.

for your goal-oriented leadership,
for your never-ending enthusiasm and energy
for your stimulating creativity
for providing a world class light source to countless generations of x-ray scientists
we all thank you very much