Roll out the wavelength shifter barrel
|The first barrels of the chemical powders PPO and bis-MSB began arriving at Fermilab in September. During the next year, Fermilab will receive 8,700 kilograms of the powders.
The first batches of two powdered chemicals, dubbed wavelength shifters, for the future NOvA neutrino project arrived by the barrel at Fermilab recently.
The American Recovery and Reinvestment Act funded the $2.1 million contract for the wavelength shifters, a crucial element for the neutrino project.
Scientists will use the two chemical powders, called PPO and bis-MSB, to change the wavelength of particles of light, called photons, into the required range for the experiment.
During the next year, Fermilab will receive 8,700 kilograms of the wavelength shifters. So far Fermilab has received 3,060 kilograms of the PPO and 120 kilograms of the bis-MSB powders.
"It takes a long time to manufacture this large an amount of the powders," said John Cooper, Fermilab NOvA project manager. Fermilab will receive the wavelength shifters in multiple shipments as they become available, he said.
As each shipment arrives, scientists from Fermilab and Northern Illinois University will test the chemical powders for quality control. Using an ultraviolet and visible spectrophotometer, for example, scientists can study the powder's transmittance, which is the area of the light spectrum the material absorbs and transmits.
"These tests tell us about the purity of the powder," said Fermilab chemist Anna Pla-Dalmau. "We requested 99.5 percent purity for NOvA, and we want to make sure that what we get works." All of the shipments received thus far have met the specifications requested by NOvA, she said.
Fermilab awarded the contract to Curtiss Laboratories, a small company in Bucks County, Pa., after a rigorous bidding and technical evaluation process. The nine-person company has reliably supplied chemicals to Fermilab for more than 10 years.
Fermilab expects the next shipment of the wavelength shifters to arrive in November.
— Elizabeth Clements
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