US high-energy physics faces compounding budget tensions

The US’s share of funding for upgrades at CERN’s Large Hadron Collider (LHC) may fall short this year, Department of Energy officials reported at the 1–2 November meeting of the High Energy Physics Advisory Panel (HEPAP), which advises DOE. The country’s flagship Long-Baseline Neutrino Facility and Deep Underground Neutrino Experiment (LBNF/DUNE), which DOE is currently replanning due to the project’s rising cost, is also putting a lot of pressure on the budget, the officials said.

From a top-line budget standpoint, DOE’s HEP program has fared well in the last five years, with Congress increasing annual funding by about $250 million, or more than 30%. Program head Jim Siegrist framed that support as a positive reaction to the long-range “P5" strategy report that HEPAP completed in 2014 ; he noted the budget growth has significantly exceeded the levels the report anticipated.

Yet, as an external review flagged last year, much of the money has gone to large and medium-scale projects the report recommended, leaving less funding for core research as well as particle accelerator and detector R&D. Siegrist and other DOE officials also expressed their desire to address that portfolio imbalance.

LHC upgrades face funding shortfall

The most immediate funding crunch concerns DOE’s contributions to major upgrade projects at the LHC. The Biden administration requested a total of $40 million for the projects this year, DOE official Mike Procario explained , a cut from the previous appropriation of $73 million and well short of the estimated requirement of about $90 million. The reduction in funding “was made very late in the budget process,” he said, and it was justified “by counting on the reconciliation bill to fully fund the projects. Any objection to making this change was answered with ‘Oh, there’s plenty of money in the reconciliation bill.’”

In September the House Science Committee did in fact propose to include about $224 million for the LHC upgrades in what is now called the Build Back Better Act, a partisan, multiyear spending bill that Democrats are aiming to pass using Congress’s budget reconciliation process. However, House Democrats removed most funding for DOE science programs, including the LHC money, in a later draft to accommodate a reduction in the bill’s total spending from $3.5 trillion to less than $2 trillion.

One of two Democratic senators demanding a top-line reduction was Sen. Joe Manchin (D-WV), who chairs the Senate committee that oversees DOE science programs. It is possible Democrats could restore the funding as negotiations continue. Manchin has not publicly stated whether he favors including funding for DOE science projects in the bill.

The outcome of the regular appropriations process for the current fiscal year is also still pending. The Senate’s proposal matches the administration’s request for the upgrades, whereas the House’s does not specify an amount. But those proposals do not necessarily predict the final outcome.

Procario said DOE has maintained contact with CERN about the situation and reported the department is contemplating shifting $25 million to the projects as a stopgap to “prevent the worst impacts.” That move would require congressional approval.

If funding for the upgrades does not meet requirements, Procario said it will be necessary to make up the shortfall in FY 2023. He also noted that doing so could delay the ramp-up of funding for the HEP program’s flagship project, LBNF/DUNE, which will examine the properties of neutrinos that are fired from Fermilab in Illinois to the Sanford Underground Research Facility in South Dakota.

“Conservative” path for neutrino experiment

Concerning LBNF/DUNE’s budget, Procario said the project’s appropriations have recently lagged behind planned levels and that, looking forward, DOE is planning a “conservative” funding profile to accommodate recent cost increases.

LBNF/DUNE’s total anticipated cost to DOE has been in flux over the last two years, rising from less than $2 billion to more than $3 billion. Some pressure stemming from shortfalls in international contributions has been alleviated with CERN’s announcement in August that it will contribute a second cryostat, a critical component for the project’s low-temperature neutrino detectors. Procario said international contributions for LBNF/DUNE now total about $570 million.

Cost increases in other areas, though, have driven the total project cost above a threshold that requires DOE to reassess the project’s basic design. Procario said DOE plans to formally reaffirm its commitment to the current design after a review this spring, when a new estimate for the project’s cost range will be established.

Instead of establishing a single, firm baseline cost for the entire project, the plan is now to baseline components as they become mature enough, Fermilab’s Chris Mossey, who directs the US portion of LBNF/DUNE, reported at the meeting. He said facilities at the project’s “far” site in South Dakota, and the first detector there, are considered completely or nearly mature and will start to be baselined in January. By contrast, a detector to be installed at the project’s “near” site at Fermilab is deemed 30% mature and will be baselined sometime between 2023 and 2025.

The project is aiming to complete the installation of two detectors at the far site by 2029, Mossey reported, but the conservative funding profile will delay completion of work on the near site’s neutrino beam and detector until 2031 and 2032, respectively. He said the strategy of completing the detectors first will allow research to begin as soon as possible on neutrinos from sources such as supernovas and hypothetical proton decays. He also noted work using the project’s centerpiece neutrino beam could be brought forward if additional funding is allocated early enough.

The House Science Committee’s proposal for the Build Back Better Act included $1.3 billion for LBNF/DUNE, but, as with the LHC upgrades, those funds have since been removed.

Consistent with the long-standing plans for LBNF/DUNE, once the project is operating with a beamline, a near-site detector, and two far-site detectors, attention will turn to potentially installing two more far-site detectors. That expansion would increase capabilities in line with recommendations in the 2014 P5 report, though the decision to proceed with it will be a matter for consideration during the next P5 process.

HEPAP poised to take global look at US particle physics

Preparations for the next P5 process are currently underway. The American Physical Society’s “Snowmass” planning exercise, which presents community views on science priorities in particle physics, will hold its summer study meeting in July, following a yearlong postponement due to the pandemic. In addition, DOE and NSF are developing a charge for a National Academies decadal survey of elementary particle physics , updating a similar report released in 2006. The official P5 process is targeted to begin in late 2022, Siegrist said, and to produce a report by May 2023, in time to inform FY 2024 appropriations and the FY 2025 budget request.

Siegrist also sought reaction from HEPAP to the idea that it could conduct an international “benchmarking” study similar to one recently conducted for DOE’s Basic Energy Sciences (BES) program. That study concluded that the US is losing the leadership position it once clearly held in facilities and research that the BES program supports.

Noting that HEP is a more globalized enterprise than BES, Siegrist remarked, “I think the key issue for the US is: How do we be the peer of choice that our international partners want to collaborate with?” As an example of that dynamic, he pointed to US work on niobium–tin superconducting magnets that will enable the planned upgrades at LHC. “Not only CERN but all of Europe embraced the US continuing working at the LHC because we brought special sauce to the table,” he said.

Siegrist also noted that the BES study identified gaps in US support for scientists’ career development, and he observed there are anecdotal cases in HEP of the US losing senior scientists to European recruitment efforts.

He more generally argued that there has not been a major study of the US position in particle physics since the “tidal shift” in the 1990s, when Europe became the field’s center of gravity. “That’s a long time ago. . . . And now we’re trying to house thousands of people on DUNE from around the world, and it might be a good time to look at this to see what we should try to change,” he said.

HEPAP chair JoAnne Hewett concluded that there was support for conducting a benchmarking study. “I think we’ve signed up for some more work, but I think we also have the chance to do some good,” she said. “That is, after all, what we all signed up for.”

Editor’s note: This article is adapted from a 17 November post on FYI, which reports on federal science policy. Both FYI and Physics Today are published by the American Institute of Physics.