Helium (He) is a noble gas with atomic number 2: a neutral helium atom has 2 protons and 2 electrons. Atomic mass 4.0026 u, electron configuration 1s2. Helium is the second lightest and second most abundant element in the observable universe.
As of 2026-09-25 · the last 10 years
Research intensity has remained flat, hovering around 35% of the element's all-time peak, which occurred in 1971.
Research intensity ran from about 38% of the element's own all-time peak in 2016 to about 35% in 2026 — flat overall, with some movement in between, and the all-time peak (1971) lies before this window. Over the same span its share of research attention across all elements fell. Among the 118 elements, helium has a larger-than-average research literature.
The number of papers involving the element rose from about 15,283 in 2016 to about 27,423 in 2025 (1.79x). That is slower than the literature as a whole grew over the same years, so the element lost ground in the wider body of research even as its own count rose.
The largest share of helium's recent research belongs to Helium Nucleosynthesis in Stellar Evolution and Cosmic Rays, a subcommunity within the broader field of dark matter and compact object astrophysics. These papers trace helium production in massive stars, supernovae, and globular groups, and its transport via cosmic rays. Helium is a minor presence in this much larger community, appearing in about 10% of its papers. This community accounts for about 16.6% of the element's recent research, a steady share compared to the previous period. The work is anchored by the Planck 2018 results (2020), cited over 14,000 times, and more recently by The Atacama Cosmology Telescope: DR6 constraints on extended cosmological models (2025), cited over 140 times.
A second major area is Helium Bubble Formation in Fusion Reactor Materials, which examines helium implantation, retention, and bubble growth in structural materials for fusion reactors. Here, helium is also a minor presence, involved in about 10% of the community's papers. This community holds about 11.4% of the element's recent research, a steady share. Key work includes Nanoscale Strain Evolution and Grain Boundary-Mediated Defect Sink Behavior in Irradiated SiC (2025), cited about 39 times, and Exploring defect behavior in helium-irradiated single-crystal and nanocrystalline 3C-SiC at 800°C (2024), cited about 41 times.
The third material community is Cryogenic Cooling and Superfluid Dynamics, focusing on dilution refrigerators, pulse tube cryocoolers, and superfluid helium-4 turbulence. In this context, helium is one strand of a broader community, appearing in about 13% of its papers. This community represents about 10.4% of the element's recent research, a steady share despite a slight dip from the previous period. Notable papers include Rotating curved spacetime signatures from a giant quantum vortex (2024), cited about 53 times, and Roton-like acoustical dispersion relations in 3D metamaterials (2021), cited over 130 times.
Overall, the composition of helium research has remained stable, with the three named communities holding steady shares while the remainder of the literature—comprising other smaller groups—accounts for about 61.6% of the element's recent research.
For a deeper look at the current state of helium research, see the Last 12 Months report or Executive Brief.
What changed in the past year: new papers, shifting applications, emerging collaborators. See the momentum over a shorter window than the decade view.
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Grouped by topic, ranked by how much each paper drives Helium's score.