Argumentation framework

2013-11-03T14:00:55Z

186.60.11.122: /* References */

{{Orphan|date=December 2012}}

'''Birks' Law''' <ref>{{cite journal|last=Birks|first=J.B.|journal=Proc. Phys. Soc.|year=1951|volume=A64|pages=874}}</ref><ref>{{cite book|last=Birks|first=J.B.|title=The Theory and Practice of Scintillation Counting|year=1964|publisher=Pergamon|location=London}}</ref> is an empirical formula for the light yield per path length as a function of the energy loss per path length for a particle traversing a [[scintillator]], and gives a relation that is not linear at high loss rates. The relation is:
:<math> \frac{dL}{dx} = L_0 \frac{\frac{dE}{dx}}{1+k_B\frac{dE}{dx}}.</math>
where ''L'' is the light yield, ''dE/dx'' is the energy loss of the particle per path length, and ''kB'' is Birks' constant, which depends on the material. ''kB'' is 0.126 mm/MeV for [[polystyrene]]-based scintillators<ref>{{cite arxiv|last=Leverington|first=B.L.|title=A 1 mm Scintillating Fibre Tracker Readout by a Multi-anode Photomultiplier |year=1970 |eprint=1106.5649v2 |author2=Anelli| author3=Campana |author4=Rosellini| class=physics.ins-det}}</ref> and 1.26–2.07 g/(MeV cm2) for [[polyvinyltoluene]]-based scintillators.<ref>{{cite journal|last= Torrisi|first=L.|title=Plastic scintillator investigations for relative dosimetry in proton-therapy |journal=Nucl. Inst. & Meth. In Phys. Res.|year=2000|volume=B161-170|pages=523}}</ref>

Birks speculated that the loss of linearity is due to recombination and quenching effects between the excited molecules and the surrounding substrate. Birks' Law has mostly been tested for [[Scintillation_(physics)#Scintillation_of_organic_scintillators|organic scintillators]]. Its applicability to inorganic scintillators is debated. A good discussion can be found in ''Particle Detectors at Accelerators: Organic scintillators''.<ref>{{cite web|last=Johnson|first=Kurtis|title=Particle Detectors at Accelerators: Organic scintillators|url=http://pdg.lbl.gov/2011/reviews/rpp2011-rev-particle-detectors-accel.pdf}}</ref> A compilation of Birks' constant for various materials can be found in ''Semi-empirical calculation of quenching factors for ions in scintillators''.<ref>{{cite journal| last=Tretyak| first=V.I.| title=Semi-empirical calculation of quenching factors for ions in scintillators| journal=Astroparticle Physics| year=2010| volume=33| pages=40–53}}</ref>

==References==
{{reflist}}


[[Category:Empirical laws]]
[[Category:Particle detectors]]

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Argumentation framework