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Created page with "==Key Stage 4== ===Meaning=== '''Penetration depth''' is how far into a material radiation can travel before being absorbed. ===About Penetration..."
==Key Stage 4==
===Meaning===
'''Penetration depth''' is how far into a [[material]] [[radiation]] can travel before being [[Absorb (Physics)|absorbed]].
===About Penetration Depth===
: '''Penetration depth''' depends on the type of [[material]] and the type of [[radiation]]:
:*High [[density]] [[material]]s are difficult to '''penetrate''' so '''penetration depth''' of a [[radiation]] will be low.
:*High [[energy]] [[radiation]] can usually '''penetrate deeper''' into a [[material]] than low [[energy]] [[radiation]].
: Knowing the '''penetration depth''' in different [[material]]s is particularly important for [[Ionising Radiation|ionising radiation]] to ensure that sources of [[Ionising Radiation|ionising radiation]] can be handled safely.
====Penetration Depth in Air====
{| class="wikitable"
|-
|[[File:AlphaPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Alpha Particle|Alpha particles]] can travel around 5cm through [[air]] ([[STP]]) before [[colliding]] with and [[ionising]] [[atom]]s or [[molecule]]s.
|}
{| class="wikitable"
|-
|[[File:BetaPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Beta Particle|Beta particles]] can travel several [[metre]]s through [[air]] ([[STP]]) before [[colliding]] with and [[ionising]] [[atom]]s or [[molecule]]s.
|}
{| class="wikitable"
|-
|[[File:GammaPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Gamma-ray|Gamma-rays]] can travel an infinite distance through [[air]] and the chances of [[colliding]] with an [[atom]] or [[molecule]] are almost non-existent.
|}
{| class="wikitable"
|-
|[[File:NeutronPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |'''[[Neutron]]s''' have a mean lifetime of around 15 minutes before they decay, so can travel several hundred [[kilometre]]s depending on their [[velocity]] before they [[Radioactive Decay|decay]] into a [[proton]] and a [[Beta Particle|beta particle]] while [[emit]]ting a [[gamma-ray]].
|}
====Penetration Depth Through Materials====
{| class="wikitable"
|-
|[[File:AlphaPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Alpha Particle|Alpha particles]] can be stopped by a thin sheet of paper.
|}
{| class="wikitable"
|-
|[[File:BetaPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Beta Particle|Beta particles]] can penetrate paper but are stopped by around 5mm thickness of [[metal]] foil.
|}
{| class="wikitable"
|-
|[[File:GammaPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Gamma-ray|Gamma-rays]] can penetrate paper and sheets of [[metal]] foil but cannot penetrate more than a few cm of [[Lead]] or a [[metre]] of [[concrete]].
|}
{| class="wikitable"
|-
|[[File:NeutronPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Neutron Radiation|Neutron radiation]] can penetrate paper and sheets of [[metal]] foil but cannot penetrate more than a few cm of [[Lead]] or a [[metre]] of [[concrete]] before they are captured by the [[Atomic Nucleus|nucleus]] of an [[atom]].
|}
===Meaning===
'''Penetration depth''' is how far into a [[material]] [[radiation]] can travel before being [[Absorb (Physics)|absorbed]].
===About Penetration Depth===
: '''Penetration depth''' depends on the type of [[material]] and the type of [[radiation]]:
:*High [[density]] [[material]]s are difficult to '''penetrate''' so '''penetration depth''' of a [[radiation]] will be low.
:*High [[energy]] [[radiation]] can usually '''penetrate deeper''' into a [[material]] than low [[energy]] [[radiation]].
: Knowing the '''penetration depth''' in different [[material]]s is particularly important for [[Ionising Radiation|ionising radiation]] to ensure that sources of [[Ionising Radiation|ionising radiation]] can be handled safely.
====Penetration Depth in Air====
{| class="wikitable"
|-
|[[File:AlphaPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Alpha Particle|Alpha particles]] can travel around 5cm through [[air]] ([[STP]]) before [[colliding]] with and [[ionising]] [[atom]]s or [[molecule]]s.
|}
{| class="wikitable"
|-
|[[File:BetaPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Beta Particle|Beta particles]] can travel several [[metre]]s through [[air]] ([[STP]]) before [[colliding]] with and [[ionising]] [[atom]]s or [[molecule]]s.
|}
{| class="wikitable"
|-
|[[File:GammaPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Gamma-ray|Gamma-rays]] can travel an infinite distance through [[air]] and the chances of [[colliding]] with an [[atom]] or [[molecule]] are almost non-existent.
|}
{| class="wikitable"
|-
|[[File:NeutronPenetrationAir.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |'''[[Neutron]]s''' have a mean lifetime of around 15 minutes before they decay, so can travel several hundred [[kilometre]]s depending on their [[velocity]] before they [[Radioactive Decay|decay]] into a [[proton]] and a [[Beta Particle|beta particle]] while [[emit]]ting a [[gamma-ray]].
|}
====Penetration Depth Through Materials====
{| class="wikitable"
|-
|[[File:AlphaPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Alpha Particle|Alpha particles]] can be stopped by a thin sheet of paper.
|}
{| class="wikitable"
|-
|[[File:BetaPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Beta Particle|Beta particles]] can penetrate paper but are stopped by around 5mm thickness of [[metal]] foil.
|}
{| class="wikitable"
|-
|[[File:GammaPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Gamma-ray|Gamma-rays]] can penetrate paper and sheets of [[metal]] foil but cannot penetrate more than a few cm of [[Lead]] or a [[metre]] of [[concrete]].
|}
{| class="wikitable"
|-
|[[File:NeutronPenetration.png|center|200px]]
| style="height:20px; width:400px; text-align:left;" |[[Neutron Radiation|Neutron radiation]] can penetrate paper and sheets of [[metal]] foil but cannot penetrate more than a few cm of [[Lead]] or a [[metre]] of [[concrete]] before they are captured by the [[Atomic Nucleus|nucleus]] of an [[atom]].
|}