DUNE collaboration completes Far Detector Interim Design Report

  • Aug 23, 2018
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The more than 1,000 scientists and engineers from 32 countries working on the inter­national Deep Under­ground Neu­trino Experi­ment (DUNE), hosted by the Depart­ment of Energy's Fermilab, achieved a mile­stone on July 29 when the collabora­tion released its 687-page Interim Design Report for the con­struc­tion of gigan­tic particle detec­tor modules a mile under­ground in South Dakota.

The three-volume interim report, which was posted on arXiv (Volume One, Volume Two, Volume Three), summar­izes the DUNE physics goals and the design of the detec­tor to meet these goals. It is based on the exper­ience that DUNE scien­tists have gained during the design and construc­tion of three-story-tall proto­type detec­tors at CERN in Europe. The final detec­tor modules, to be sited in the United States, will be about 20 times the size of the proto­types.

[photo of Asst. Prof. Kendall Mahn]

Kendall Mahn, MSU assistant professor of physics and astronomy, is one of the far detec­tor calibra­tion task force leaders for the DUNE collabora­tion.
Photo credit: Harley Seeley.

“I am currently serving as one of the far detec­tor calibra­tion task force leaders, so we drafted the sec­tion on calibra­tion strategy and sys­tems,” said Kendall Mahn, Assis­tant Profes­sor in MSU's Depart­ment of Physics and Astro­nomy. “DUNE is an excit­ing experi­ment because of the many chal­lenges we face, and calibra­tion is a signifi­cant one—to under­stand the uni­formity and stability at a few per­cent of an enor­mous (58m long!) cryo­genic volume.”

“It is amazing how much work this collabora­tion has accom­plished in the last couple of years,” said DUNE co-spokes­person Stefan Soldner-Rembold, profes­sor at the Univer­sity of Man­chester in the UK.

“The Interim Design Report is a major step toward the prepara­tion of the final, more detailed, Techni­cal Design Re­port, which we will write next,” he said.

The DUNE Techni­cal Design Re­port for the first two detec­tor modules will be final­ized rough­ly a year from now and will be the blue­print for the construc­tion of those modules.

“The Interim Design Report presents an enor­mous body of work,” said Sam Zeller of Fermilab, who served as the co-editor of the docu­ment together with Tim Bolton of Kansas State Univer­sity. “The docu­ment doesn't just con­tain drawings. It also includes detailed tech­nical speci­fica­tions and photos of the proto­type equip­ment that was built during the last 12 months.”

DUNE is an experi­ment to un­lock the mys­teries of neu­trinos, the par­ticles that could be the key to explain­ing why matter and the uni­verse exist. The experi­ment will send a neu­trino beam genera­ted by Fermilab's particle accelera­tor com­plex in Illinois 800 miles (1300 km) straight through the Earth to the DUNE far de­tec­tor modules to be built at the San­ford Under­ground Re­search Facil­ity in Lead, South Dakota. DUNE scien­tists also will use the large detec­tor modules to search for rare sub­atomic proces­ses such as proton decay and watch for neu­trinos stem­ming from the explo­sion of stars in our galaxy.

“The DUNE physics program addresses key ques­tions that will give us fur­ther in­sight in the under­standing of the uni­verse,” said DUNE collab­orator Albert de Roeck, leader of the CERN experi­mental neu­trino group. “Neu­trinos are still very enig­matic particles and no doubt will sur­prise us in future.”

Ground­breaking for the con­struc­tion of the caverns that will host the DUNE modules took place in July 2017, and the experi­ment is ex­pected to be opera­tional with two far detec­tor modules online by 2026. Ultimate­ly, DUNE will com­prise four far detec­tor modules filled with a total of 70,000 tons of liquid argon, as well as a smal­ler near detec­tor at Fermilab.

The Interim Design Report speci­fies the two tech­nologies that DUNE scien­tists will use for the far detec­tor: single- and dual-phase time pro­jec­tion cham­bers filled with cold, crys­tal clear liquid argon, the same tech­nologies used to build the two proto­type detec­tors at CERN, known as the ProtoDUNE detec­tors.

“Design­ing liquid-argon time projec­tion chambers of this size is an un­preceden­ted ef­fort requir­ing state-of-the-art tech­nologies,” said CNRS Research Direc­tor Dario Autiero of the French National Insti­tute of Nuclear and Par­ticle Physics, In­stitut de Physique Nuc­leaire, Lyon, and DUNE collabora­tor. “DUNE pushes the tech­nological limits in detec­tor design, high-voltage sys­tems, pho­ton detec­tion sys­tems, low-noise elec­tronics, and high-band­width data acqui­sition sys­tems. DUNE collabora­tors have been de­veloping these tech­nologies for years, and they are being deployed in the two proto­type detec­tors at CERN.”

Both types of far detec­tor modules will record images of particle tracks created by neu­trinos colliding with argon atoms. In the single-phase tech­nology, the en­tire volume of the detec­tor is filled with liquid argon, and a horizon­tal high-vol­tage elec­tric field “projects” the par­ticle tracks towards the walls of the detec­tor. Arrays of thin wires placed in front of the detec­tor walls cap­ture the sig­nals crea­ted by the par­ticle tracks and send them to a data acqui­si­tion system.

“These giant detec­tors are being designed and de­veloped by a great team of scien­tists and engin­eers, work­ing to­gether to un­veil the sec­rets of the uni­verse,” said Inés Gil-Botella, leader of the CIEMAT neu­trino group, Madrid, Spain, and mem­ber of the DUNE collabora­tion. “Care­ful plan­ning and coordina­tion is the key to the suc­cess of DUNE.”

The DUNE collabora­tion com­prises 175 institu­tions from 32 coun­tries: Armenia, Brazil, Bulgaria, Canada, Chile, China, Colom­bia, Czech Repub­lic, Fin­land, France, Greece, India, Iran, Italy, Japan, Madagas­car, Mexico, Nether­lands, Para­guay, Peru, Poland, Portu­gal, Romania, Rus­sia, South Korea, Spain, Sweden, Switzer­land, Turkey, Ukraine, United King­dom and Uni­ted States. More informa­tion is at dunescience.org.

To learn more about the DUNE, the Long-Base­line Neu­trino Facil­ity that will house the experi­ment, and the PIP-II par­ticle accelera­tor project at Fermi­lab that will power the neu­trino beam for the experi­ment, visit www.fnal.gov/dune.

[graphical representation of DUNE experiment]

Banner image: DUNE is an experi­ment to un­lock the mys­teries of neu­trinos, the par­ticles that could be the key to ex­plaining why mat­ter and the uni­verse exist. The experi­ment will send a neu­trino beam genera­ted by Fermi­lab's par­ticle accelera­tor com­plex in Illinois 800 miles straight through the Earth to the DUNE far detec­tor modules to be built at the San­ford Under­ground Re­search Facil­ity in South Dakota.

For additional information, see