Transcript Excitation of Quantum Jumps by Collisions

Muonic Atoms
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to produce the muon…
p  n  n  n 
      
or

or
p  n  p  p 

      
where p: the proton n: the neutron
T1 2  2.5 108[s]
π:the pion ν:the neutrino
μ:the muon
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The nature of Muon


Muons have a charge e, a mass equal
to 207･m0
Muons themselves decay.
   e  e  
   e  e  
T1 2  2.2 106[s]
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
Before Muons decay, they are captured
into atomic orbits and occupy the orbits
of electrons.
They make transitions from the outer
to inner orbits.
They radiate light in the x-ray region
of the spectrum.
Muons behave like heavy electrons.
4 0 2 2
~Bohr model
rn 
n
2
Ze m
ex. 12Mg

12
r
(
e
)

4
.
5

10
[m]
electrons: 1

r
(
e
)

14
1
r
(

)


2
.
2

10
[m]
muons: 1
207

Muon is closer to the nucleus than electron.
The quantum energy in a muonic atom is larger
by the ratio of the masses than the energy of
transition in an electronic atom.

Muonic atoms are objects of the nuclear
physics research.
Muonic terms diagram for an atom
with Z=60


This energy transitions
are similar to the
hydrogen atom.
The energy scale is MeV
unlike the hydrogen.
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Summary ~Muonic atoms
Muons have a charge e and behave like
heavy electrons.
Therefore, we can apply the Bohr model.
 Muons are produced in decaying pions.
 Muons themselves decay.

~or else
They are captured by atomic nuclei,
make transitions, and radiate light.
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Excitation of Quantum
Jumps by Collisions
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the ionization of atoms by using
electron collisions
Ionization events are detected
as a current to the plate.
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Franck-Hertz’s experiment
5eV
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~process~
electrons are accelerated ~up to a grid
inelastic collisions
(between electrons and atoms)
electrons lose most of
kinetic energy
gas atoms receive the energies
partially or completely from
electrons
they fall back to the grid
by a braking voltage VB
the anode A current is measured
Improved experimental setup in
Franck-Hertz’s experiment
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Summary


Electron collision experiments prove
the existence of discrete excitation
states in atoms.
Franck-Hertz’s experiment establish
the Bohr’s postulates.
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