(3He)helium

(3He)helium Property

Melting point:

-272.14°C

Boiling point:

-269.97°C (estimate)

Density 

0.041 g/cm3

form 

gas

InChI

InChI=1S/He/i1-1

InChIKey

SWQJXJOGLNCZEY-BJUDXGSMSA-N

SMILES

[3He]

EPA Substance Registry System

Helium, isotope of mass 3 (14762-55-1)

Safety

RIDADR 

UN1046 - class 2 - Helium, compressed

WGK Germany 

3

RTECS 

MH6520000

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H280Contains gas under pressure; may explode if heated

Precautionary statements

P410+P403Protect from sunlight. Store in a well-ventilated place.

(3He)helium Chemical Properties,Usage,Production

Uses

In nuclear fusion reactions, the energy released by the fusion of the three isotopes of hydrogen with helium-3 is the greatest of all nuclear fusion reactions. Therefore, helium-3 is the most ideal fuel for nuclear fusion.

Application

Currently, the applications of helium-3 are limited, primarily in neutron detection and lung medical imaging. Helium-3 has a high thermal neutron absorption cross-section, making it the converter gas in neutron detectors. When helium-3 captures a neutron, it converts into a tritium ion and a hydrogen ion (proton), releasing 0.764 MeV of energy. By analyzing the composition of the produced gas, the neutron radiation dose of the radioactive material can be determined.

Chemical Properties

Helium-3,3He, has been known as a stable isotope since the middle-1930s and it was suspected that its properties were markedly different from the common isotope, helium-4.

History

The development of nuclear fusion devices in the 1950s yielded workable quantities of pure helium-3 as a decay product from the large tritium inventory implicit in maintaining an arsenal of fusion weapons.

Definition

ChEBI: The stable isotope of helium with relative atomic mass 3.016029. The least abundant (0.000137 atom percent) isotope of naturally occurring helium.