Time-of-flight detector

<p>A time-of-flight (TOF) detector is a <a href="/facts/Particle_detector/rYj0qKtA">particle detector</a> which can discriminate between a lighter and a heavier <a href="/facts/Elementary_particle/CTFDM97U">elementary particle</a> of same momentum using their <a href="/facts/Time_of_flight/DSINDYyn">time of flight</a> between two <a href="/facts/Scintillator/vhxA1Ufo">scintillators</a>. The first of the scintillators activates a clock upon being hit while the other stops the clock upon being hit. If the two masses are denoted by 
  
    
      
        
          m
          
            1
          
        
      
    
    {\displaystyle m_{1}}
  
and 
  
    
      
        
          m
          
            2
          
        
      
    
    {\displaystyle m_{2}}
  
 and have velocities 
  
    
      
        
          v
          
            1
          
        
      
    
    {\displaystyle v_{1}}
  
 and 
  
    
      
        
          v
          
            2
          
        
      
    
    {\displaystyle v_{2}}
  
 then the time of flight difference is given by
</p>

Δ
        t
        =
        L
        
          (
          
            
              
                1
                
                  v
                  
                    1
                  
                
              
            
            −
            
              
                1
                
                  v
                  
                    2
                  
                
              
            
          
          )
        
        ≈
        
          
            
              L
              c
            
            
              2
              
                p
                
                  2
                
              
            
          
        
        (
        
          m
          
            1
          
          
            2
          
        
        −
        
          m
          
            2
          
          
            2
          
        
        )
      
    
    {\displaystyle \Delta t=L\left({\frac {1}{v_{1}}}-{\frac {1}{v_{2}}}\right)\approx {\frac {Lc}{2p^{2}}}(m_{1}^{2}-m_{2}^{2})}

<p>where 
  
    
      
        L
      
    
    {\displaystyle L}
  
 is the distance between the scintillators. The approximation is in the relativistic limit at momentum 
  
    
      
        p
      
    
    {\displaystyle p}
  
 and 
  
    
      
        c
      
    
    {\displaystyle c}
  
 denotes the speed of light in vacuum.
</p>

Time-of-flight detector open-in-new

Time-of-flight detector