What kinds of transitions produce x rays
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What kinds of transitions produce x-rays?. An x-ray tube:. motor rotates tungsten to prevent over- heating. X-rays are produced 2 ways in an x-ray tube:. x-rays. Electron from cathode knocks an inner e- out, and an outer e - falls down to the empty orbital, emitting an x-ray.

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What kinds of transitions produce x-rays?

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What kinds of transitions produce x rays

What kinds of transitions produce x-rays?


What kinds of transitions produce x rays

An x-ray

tube:

motor rotates

tungsten to

prevent over-

heating


What kinds of transitions produce x rays

X-rays are produced 2 ways in an x-ray tube:

x-rays

  • Electron from

  • cathode knocks

  • an inner e- out,

  • and an outer e-

  • falls down to the

  • empty orbital,

  • emitting an x-ray.

2. Electron ricochets

around nucleus.

As it decelerates,

x-rays are emitted.


What kinds of transitions produce x rays

CAT (or CT) scans – Computed Axial Tomography

As the x-ray source

and detector rotate,

a 3-D picture is built up

x-ray

detector

x-ray

source

As the patient moves through, many slices are taken….


What kinds of transitions produce x rays

getting a CAT scan…

brain CT scans


What kinds of transitions produce x rays

The idea behind particle accelerators (atom smashers):

________ particles

+ high __________:

old

energy

_______ particles because

________

new

E = mc2

The more the ________________ given to the old particles,

the more _________________ of the new ones by E = ______.

energy

the mass

mc2


What kinds of transitions produce x rays

Ex: Early particle accelerators

used _______________ generators:

van derGraff

voltage V

  • high _______________

  • work done on

    a charge q:

    W=

  • high _______________

  • work done on

    a charge q:

    W =

qV

Ex: How much KE will a proton gain when it is

accelerated through a potential difference of 300,000 V?

= DKE

W = qV

v ~ 7.6 x 106 m/s

crosses the Earth

in 1.7 s, but still

only 2.5% of c

W =

(1 e)(300,000 V)

W =

300,000 eV


What kinds of transitions produce x rays

Ex: An example of a modern particle accelerator is

the_____________________ .

cyclotron.

v

v

v

The _______________ field accelerates the particle.

The ______________ field is ____________________ to v, so it

only causes the particle to ___________________________ .

electric

magnetic

perpendicular

turn in a circle


What kinds of transitions produce x rays

the very

first cyclotron

world’s biggest

cyclotron

a 1939 cyclotron


What kinds of transitions produce x rays

The particle accelerator

at Cornell University

accelerator

storage ring

for positrons


What kinds of transitions produce x rays

SLAC – The Stanford Linear Accelerator Center


What kinds of transitions produce x rays

Fermilab in Chicago – another accelerator

built in the shape of a circle.


What kinds of transitions produce x rays

Find the ladder for scale.

…inside Fermilab


What kinds of transitions produce x rays

One of the largest – at CERN - Angels and Demons


What kinds of transitions produce x rays

A detector at CERN

led to the discovery

of the W and Z

particles – carriers of

the weak force


What kinds of transitions produce x rays

As accelerators with higher and higher _____________ were built, particles with bigger and bigger ____________were discovered.

energy

masses

There seemed to be no _____________

to the________________ of newly

discovered particles.

pattern

hundreds

_____________________

_____________________

tracks of subatomic

particles

Finally, the _________________________ was worked out in

the _______________ . It explained how all of the particles

are made of ________________ fundamental particles and

their _________________________ .


What kinds of transitions produce x rays

Decay of a K+ meson in a bubble chamber:


What kinds of transitions produce x rays

cloud chambers: use

supersaturated gases


What kinds of transitions produce x rays

Bubble chamber:

1 Fill a large cylinder with a liquid heated to just below its boiling point.

2. As particles enter the chamber,

a piston suddenly decreases its

pressure, and the liquid becomes

superheated.

3. Charged particles create an

ionization track, around which

the liquid vaporizes, forming

microscopic bubbles.


What kinds of transitions produce x rays

Ye

Olde

Bubble

Chamber

from

Fermilab

(Chicago)


What kinds of transitions produce x rays

bubble chamber tracks


What kinds of transitions produce x rays

As accelerators with higher and higher _____________ were built, particles with bigger and bigger ____________were discovered.

energy

masses

There seemed to be no _____________

to the________________ of newly

discovered particles.

pattern

hundreds

_____________________

_____________________

tracks of subatomic

particles

Standard Model

Finally, the _________________________ was worked out in

the _______________ . It explained how all of the particles

are made of ________________ fundamental particles and

their _________________________ .

1960s

twelve

antiparticles


What kinds of transitions produce x rays

_______

_______

The Standard Model: All matter (or antimatter) is

made up of ___________or combinations of____________.

leptons

quarks

  • Other 12’s:

  • a dozen

  • Jupiter’s period

  • months in year

  • hours in day

  • inches in foot

  • disciples

  • yrs. of youth

  • teenage elves

quarks

leptons

Let’s look

at leptons first.

read the fine print

__________________


What kinds of transitions produce x rays

increasing____________________

only found at

high energies

(high temps.)

everyday

low-energy

leptons

mass/energy

Neutrinos

have _______

_____ mass.

almost

no

  • Lepton means________________________

  • Leptons all have charge _______or__________________

  • Their antiparticles are charged __________________

  • They occur____________________—they do not

  • ___________________________________________.

“light weight.”

-1e

0 (neutral).

+1e or 0.

by themselves

combine to form bigger particles


What kinds of transitions produce x rays

increasing __________________

only found at

high energies

(high temps.)

everyday,

low-energy

quarks

mass/energy

  • Quarks all have charge _________or ___________

  • Their antiparticles are charged _________ or_________

  • They ___________________by themselves because you

  • cannot have a particle with a_________________________.

  • They occur in groups of _____________________

(-1/3)e.

(+2/3)e

(+1/3)e

(-2/3)e

never occur

non-integer charge

2’s or 3’s.


What kinds of transitions produce x rays

q

q

q

q

q

particles

made from

___________

quarks

“mes-”

means

_________

masses

“bary-”

means

_______

masses

middle

heavy

qqq

Must be all

__________ or

all_____________

or

matter

antimatter


What kinds of transitions produce x rays

Ex. A certain particle is made up of

3 quarks: 2 ________ quarks and

1 _____________ quark.

u

d

u

up

down

What is the total charge of the particle?

Add up the charges:

u:

(+2/3) e

u:

(+2/3) e

[(+2/3) + (+2/3) + (-1/3)] e

d:

(-1/3) e

= 1 e

Is this a baryon, a meson or a lepton?

3 quarks  a baryon

proton.

This particle is also known as a________________


What kinds of transitions produce x rays

d

d

Ex. A certain particle is made up of 2

quarks: 1 ____ quark and 1 __________

quark.

u

antidown

up

What is the total charge of the particle?

Add up the charges:

(+2/3) e

u:

[(+2/3) + (+1/3)] e

:

(+1/3) e

= 1 e

Is this a baryon, a meson or a lepton?

2 quarks  a meson

p+ (positive pion).

This particle is also known as a ______________________


What kinds of transitions produce x rays

Ex. A certain particle is made up of

3 quarks: 1 _____ quark and 2 ________

quarks.

d

up

down

d

u

What is the total charge of the particle?

u:

(+2/3) e

Add up the charges:

d:

(-1/3) e

[(+2/3) + (-1/3) + (-1/3)] e

d:

(-1/3) e

= 0 e

Is this a baryon, a meson or a lepton?

3 quarks  a baryon

neutron.

This particle is also known as a_____________________


What kinds of transitions produce x rays

Ex. A certain particle is made up of

3 quarks: 2 ________________ quarks

and 1 _________________ quark.

u

u

u

u

d

d

d :

u :

u :

u

u

u

u

u

u

d

d

d

antiup

antidown

What is the total charge of the particle?

(-2/3) e

Add up the charges:

[(-2/3) + (-2/3) + (+1/3)] e

(-2/3) e

= -1 e

(+1/3) e

u

u

Compare this one: to:

d

antiproton

The left-hand particle is an _______________________ . It is

an example of ___________________ . It has the __________

mass as the proton, but the _________________ charge.

same

antimatter

opposite


What kinds of transitions produce x rays

s

s

u

u

u

b

d

d

d

Determine the charge and type of each particle.

a whole number of e's

The total charge must be ____________________________


What kinds of transitions produce x rays

What is matter made up of?

neutron or

a proton


What kinds of transitions produce x rays

Forces

The Fundamental __________________ of Nature:


What kinds of transitions produce x rays

Ex: How can gravity hold Earth to the Sun if it is the

weakest force?

  • Earth and Sun have a lot of ______________

  • Earth and Sun are _________________ , so the

  • __________________________ force is not important.

  • 3. Earth and Sun are_______________ , so the

  • ________________________ forces are not important.

mass.

neutral

electromagnetic

far apart

two nuclear

Ex: The total amount of mass-energy in the universe

is:

ordinary matter: ______% (baryons and leptons)

dark matter: ______% (unknown)

dark energy: ______% (unknown)

5

23

72


What kinds of transitions produce x rays

Total after

Conservation Laws:

Total before =________________

Charge q

1. _____________________ is always conserved.

q1 + q2 + …

q1’ + q2’ + …

=

momentum (p)

  • In the absence of_______________ , ________________

  • is always conserved.

friction

=

p1’ + p2’ + …

p1 + p2 + …

3. In the absence of________________, ________________

is always conserved.

energy (E)

friction

Modern physics:

Classical physics:

ET ET’

mass-E mass’-E’

=

=

=

using E = mc2

KE + PE KE’ + PE’


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