The element with an atomic structure similar to an alpha particle is Helium (He).

Here's why:

* Alpha particle: An alpha particle is a positively charged particle consisting of two protons and two neutrons. It's essentially the nucleus of a Helium-4 atom.

* Helium: Helium has an atomic number of 2, meaning it has two protons in its nucleus. The most common isotope of Helium, Helium-4, also has two neutrons.

Therefore, an alpha particle has the same composition as a Helium-4 nucleus: 2 protons and 2 neutrons. The only difference is that an alpha particle is typically emitted from a radioactive nucleus, while a Helium atom exists as a stable element.