Copper-64

⁶⁴Cu has a half-life of 12.701 ± 0.002 hours and decays by 17.86 (± 0.14)% by positron emission to ⁶⁴Ni, 39.0 (± 0.3)% by beta decay to ⁶⁴Zn, 43.075 (± 0.500)% by electron capture to ⁶⁴Ni, and 0.475 (± 0.010)% gamma radiation/internal conversion. These emissions are 0.5787 (± 0.0009) and 0.6531 (± 0.0002) MeV for beta minus and positron respectively and 1.35477 (± 0.00016) MeV for gamma.

The main oxidation states of copper are I and II since Cu³⁺ is too powerful to exist in biochemical systems. Furthermore, copper(I) exists as a strong complex in aqueous solution and is not often seen. Copper(II) forms mononuclear complexes that are paramagnetic and prefers ligands of sulfur and nitrogen.

Copper is essential in the human body as both a catalyst and as part of enzymes. Copper is mainly involved in redox reactions throughout the body, but also plays a role in iron transportation in blood plasma.

Copper-64 can be technically reproduced by several different reactions with the most common methods using either a reactor or an accelerator. Thermal neutrons can produce ⁶⁴Cu in low specific activity (the number of decays per second per amount of substance) and low yield through the ⁶³Cu(n,γ)⁶⁴Cu reaction. At the University of Missouri Research Reactor Center (MURR) ⁶⁴Cu was produced using high-energy neutrons via the ⁶⁴Zn(n,p)⁶⁴Cu reaction in high specific activity but low yield. Using a biomedical cyclotron the ⁶⁴Ni(p,n)⁶⁴Cu nuclear reaction can produce large quantities of the nuclide with high specific activity.

...
Wikipedia