Neutron emission

Neutron emitters to left of lower dashed line

Z →	0	1	2
n ↓	n	H	He	3	4
0		1H		Li	Be	5	6
1	1n	2H	3He	4Li	5Be	B	C	7
2	2n	3H	4He	5Li	6Be	7B	8C	N	8
3		4H	5He	6Li	7Be	8B	9C	10N	O	9
4	4n	5H	6He	7Li	8Be	9B	10C	11N	12O	F	10
5		6H	7He	8Li	9Be	10B	11C	12N	13O	14F	Ne	11
6		7H	8He	9Li	10Be	11B	12C	13N	14O	15F	16Ne	Na	12
		7	9He	10Li	11Be	12B	13C	14N	15O	16F	17Ne	18Na	Mg	13
		8	10He	11Li	12Be	13B	14C	15N	16O	17F	18Ne	19Na	20Mg	Al	14
			9	12Li	13Be	14B	15C	16N	17O	18F	19Ne	20Na	21Mg	22Al	Si
				10	14Be	15B	16C	17N	18O	19F	20Ne	21Na	22Mg	23Al	24Si
					11	16B	17C	18N	19O	20F	21Ne	22Na	23Mg	24Al	25Si
						12	18C	19N	20O	21F	22Ne	23Na	24Mg	25Al	26Si
							13	20N	21O	22F	23Ne	24Na	25Mg	26Al	27Si
								14	22O	23F	24Ne	25Na	26Mg	27Al	28Si

Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13. However, the decay of helium-5 is also (by definition) a case of alpha-decay.

Many heavy isotopes, most notably californium-252, emit neutrons among the products of a different radioactive decay process, spontaneous fission.

Neutrons are absorbed and emitted in the process of nuclear fission, a nuclear chain reaction propagated by neutrons. Delayed neutrons emitted by neutron-rich fission products aid control of nuclear reactors by making reactivity change much slower than it would be for prompt neutrons alone.

See also

• Neutron radiation

External links

• The LIVEChart of Nuclides - IAEA with filter on delayed neutron emission decay, in Java or HTML
• Nuclear Structure and Decay Data - IAEA with query on Neutron Separation Energy