Lead by glass

For the scientific research on molecular structures of solids, flatness is the key. To deliver as many neutrons as possible through the guide tubes, ultra-smooth surfaces with a roughness of less than one nanometer are necessary. „Not even individual atoms can project on the insides of neutron guides“, explains Dr. Christian Schanzer, Chief Operating Officer (COO) at SwissNeutronics, the leading manufacturer of neutron guides. BOROFLOAT®, the special float glass by SCHOTT is the base for the products as a material. „The outstanding properties of this special float glass gives us a clear competitive edge“, states Dr. Schanzer.

This advantage just paid off again: SwissNeutronics secured access to China’s market and are the supplier of neutron guides for the spallation source at the Institute of High Energy Physics in Dongguan near Hong Kong. The system will have up to 600 meters of guide tubes used in 20 beamlines. „The quality and the good price-performance ratio of BOROFLOAT® allowed us to submit a quotation which was better than all others“, Schanzer is pleased. The system is planned to be put into service this year yet and be one of the biggest of its kind.

This deal was an important milestone in the company’s history, a leader in the neutron guide market holding 60 percent. An important advantage, since only about 20 research institutes in the world can even be considered as customers.

Building neutron guides requires extreme precision. After all, the BOROFLOAT® supermirror coating only reflects neutrons at very low angles. „If a wall is slanted or not smooth enough, the neutrons will penetrate the material, which must be avoided“, Dr. Schanzer states. SwissNeutronics coats the glass with up to 10,000 nano-thin layers. This is where BOROFLOAT® provides the best extremely flat surface. Schanzer: „We’re practically at the physical limits: it can’t be topped.“

The Swiss company’s inclination to perfection is not an end unto itself but there’s a simple reason: The better the quality of the neutron guides, the greater the neutron yield for scientific experiments. „Last year we replaced a guide section at the Joint Institute for Nuclear Research in Dubna, Russia“, Dr. Schanzer reports. „The researcher can now use six times as many neutrons in his experiment than before. In other words: What previously took a day can now be done in four hours.“

SwissNeutronics has already been working with SCHOTT since 1999. Float glass was the material of choice from the beginning, but it wasn’t until BOROFLOAT® that the high standards of research were truly met. The special float glass by SCHOTT now serves as a reference substrate for quality assurance at SwissNeutronics. Dr. Schanzer: „No other material has this high and consistent of quality – and this already for decades. It therefore provides ideal requirements for improving our coatings. BOROFLOAT® is our opportunity to improve the quality considerably in this respect.“

Material for high-tech applications

In addition to the extremely low roughness the even thickness and high homogeneity are properties which predestine BOROFLOAT® for high-tech applications. Add to this the high chemical and thermal resistance and high mechanical strength: The high boron ratio, which has a shielding effect, is also extremely important, especially for building neutron guides; it practically ‘catches’ neutrons. The microfloat process, a special manufacturing method, is key for the unique properties of BOROFLOAT®. The glass ribbon ‚floats‘ – it’s ‚floated‘ – in a bath of liquid tin to then cool down. The high optical quality of BOROFLOAT® comes from a special ‚secret recipe‘ and still unrivaled in the field of flat glass.

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