Despite officials’ wishes to increase support for core research as well as accelerator and detector R&D, much of the DOE’s high-energy physics program money has gone to major initiatives, such as the LBNF/DUNE neutrino experiment.
The United States’ contribution to enhancements at CERN’s Large Hadron Collider (LHC) may fall short this year, according to Department of Energy officials speaking at the High Energy Physics Advisory Panel (HEPAP) conference on November 1–2. Officials said the country’s flagship Long-Baseline Neutrino Facility and Deep Underground Neutrino Experiment (LBNF/DUNE), which DOE is currently replanning due to rising costs, is also putting a strain on the budget.
In terms of top-line budgeting, Congress has increased annual funding for DOE’s HEP program by nearly $250 million, or more than 30%, during the last five years. Jim Siegrist, the program’s director, characterized the support as a good response to HEPAP’s long-range “P5” strategy study, which was completed in 2014; he observed that budget growth had well above the levels predicted in the report.
However, as an external evaluation pointed out last year, much of the financing has gone to large and medium-scale programs, leaving less money for core research and particle accelerator and detector R&D. Other DOE officials, including Siegrist, have voiced a willingness to remedy the portfolio mismatch.
There is a budget gap for LHC enhancements.
The most pressing financing shortfall involves DOE’s contributions to major LHC improvement programs. According to DOE official Mike Procario, the Biden administration sought a total of $40 million for the projects this year, a reduction from the prior appropriation of $73 million and much below the estimated requirement of around $90 million. He explained that the funding cut was decided “late in the budget process” and that it was justified “by banking on the reconciliation bill to fully fund the projects.” “Oh, there’s plenty of money in the reconciliation bill,” anyone who objected to the adjustment was told.
In September, the House Science Committee proposed including $224 million for LHC enhancements in what is now known as the Build Back Better Act, a political, multiyear spending package that Democrats hope to pass through the budget reconciliation process in Congress. However, in a later iteration of the plan, House Democrats withdrew most funding for DOE science initiatives, including the LHC financing, in order to reduce the bill’s overall spending from $3.5 trillion to less than $2 trillion.
Sen. Joe Manchin (D-WV), who chairs the Senate committee that oversees DOE research programs, was one of two Democratic senators who demanded a top-line decrease. While negotiations continue, it’s possible that Democrats will reinstate financing. Manchin has not stated publicly if he supports the measure providing financing for DOE science projects.
The outcome of the current fiscal year’s regular appropriations procedure is likewise awaited. The Senate’s plan for the upgrades is identical to the administration’s request, although the House’s does not give a dollar amount. However, those proposals may not always indicate what will happen in the end.
DOE has been in communication with CERN about the situation, according to Procario, and the department is considering allocating $25 million to the programs as a stopgap to “avoid the worst repercussions.” This would necessitate congressional permission.
If funding for the upgrades falls short of expectations, Procario said the difference will have to be made up in FY 2023. He also warned that doing so could delay the HEP program’s flagship project, LBNF/DUNE, which will investigate the characteristics of neutrinos shot from Fermilab in Illinois to the Sanford Underground Research Facility in South Dakota.
The neutrino experiment’s “conservative” course
Procario said the project’s appropriations have recently trailed behind expected levels, and that DOE is proposing a “conservative” funding profile in the future to account for recent cost increases.
The entire estimated cost of LBNF/DUNE to DOE has fluctuated over the last two years, ranging from less than $2 billion to more than $3 billion. CERN’s statement in August that it would contribute a second cryostat, a vital component for the project’s low-temperature neutrino detectors, relieved some of the strain caused by deficits in international donations. According to Procario, international contributions to LBNF/DUNE have now reached $570 million.
Cost rises in other sectors, on the other hand, have pushed the entire project cost above a point where DOE must rethink the project’s basic concept. After a review this spring, when a new estimate for the project’s cost range will be created, Procario said DOE plans to formally reaffirm its support to the current design.
Instead of creating a single, clear baseline cost for the entire project, Fermilab’s Chris Mossey, who oversees the US side of LBNF/DUNE, indicated at the meeting that the aim is now to baseline components as they become mature enough. He added the project’s “far” site in South Dakota, as well as the first detector there, are “fully or virtually mature,” and baseline work would begin in January. A detector to be placed at the project’s “near” location at Fermilab, on the other hand, is considered 30 percent mature and will be baselined between 2023 and 2025.
According to Mossey, the project hopes to finish installing two detectors at the far site by 2029, however due to the project’s conservative funding profile, work on the near site’s neutrino beam and detector will not be completed until 2031 and 2032, respectively. He claims that constructing the detectors first will allow research on neutrinos from supernovas and hypothetical proton decays to begin as soon as possible. He also mentioned that if more financing is granted early enough, construction on the project’s centerpiece neutrino beam could be accelerated.
The House Science Committee’s Build Back Better Act proposal included $1.3 billion for LBNF/DUNE, however those monies have subsequently been deleted, as have the LHC enhancements.
Following LBNF/long-term DUNE’s objectives, once the project is up and running with a beamline, a near-site detector, and two far-site detectors, emphasis will shift to the possibility of adding two more far-site detectors. That expansion would boost capabilities in line with the 2014 P5 report’s recommendations, albeit the decision to go ahead with it will be decided during the next P5 process.
HEPAP is getting ready to take a global look at particle physics in the United States.
The next P5 process is now in the planning stages. Following a year-long suspension due to the pandemic, the American Physical Society’s “Snowmass” planning exercise, which delivers community views on science goals in particle physics, will have its summer study conference in July. In addition, DOE and NSF are working on a proposal for a National Academies decadal survey of elementary particle physics, which will update a 2006 report. According to Siegrist, the official P5 process will begin in late 2022 and end in May 2023, in time to inform FY 2024 allocations and the FY 2025 budget request.
Siegrist also inquired about HEPAP’s reaction to the concept of doing an international “benchmarking” study similar to one recently completed for the DOE’s Basic Energy Sciences (BES) program. According to the findings of that study, the United States is losing its clear leading position in the facilities and research that the BES program supports.
“I think the major problem for the US is: How do we be the peer of choice that our international partners want to engage with,” Siegrist said, noting that HEP is a more globalized organization than BES. He cited US development on niobium–tin superconducting magnets, which would enable the LHC’s planned enhancements, as an example of this dynamic. “Not only CERN, but Europe as a whole embraced the US continuing to work at the LHC because we offered something unique to the table,” he explained.
According to Siegrist, the BES study highlighted deficiencies in US support for scientists’ career advancement, and there are anecdotal incidents in HEP of the US losing prominent scientists due to European recruitment efforts.
He went on to say that since the “tidal shift” in the 1990s, when Europe became the field’s center of gravity, there hasn’t been a serious assessment of the US position in particle physics. “Wow, that was a long time ago…” And now since we’re trying to house thousands of people from all over the world on DUNE, it might be a good moment to take a look at this and see what we can do differently,” he said.
HEPAP chair JoAnne Hewett came to the conclusion that a benchmarking study would be beneficial. “I believe we’ve signed up for more work, but I also believe we have the opportunity to do some good,” she remarked. “After all, that’s what we all signed up for.”