x ray production
Download
Skip this Video
Download Presentation
X-ray Production

Loading in 2 Seconds...

play fullscreen
1 / 30

X-ray Production - PowerPoint PPT Presentation


  • 95 Views
  • Uploaded on

X-ray Production. kVp KINETIC ENERGY OF ELECTRONS. CATHODE --------. MADE OF TUNGSTEN + 1%-3% THORIUM. TUNGSTEN. Z # 74 MELTING POINT- 3,410 DEG. CELSIUS. THORIUM. Z # 90. THERMIONIC EMISSION. CATHODE HEATED UP TO AT LEAST 2,200 DEG. CELSIUS. ANODE +++++. TUNGSTEN

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' X-ray Production' - chase-williamson


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
cathode
CATHODE --------

MADE OF TUNGSTEN+ 1%-3% THORIUM

tungsten
TUNGSTEN

Z # 74

MELTING POINT- 3,410 DEG. CELSIUS

thorium
THORIUM

Z # 90

thermionic emission
THERMIONIC EMISSION

CATHODE HEATED UP TO AT LEAST 2,200 DEG. CELSIUS

anode
ANODE +++++

TUNGSTEN

TARGET

tungten as target
TUNGTEN AS TARGET

HIGH Z# - 74------EFFICIENCY OF X-RAY PRODUCTION

HIGH MELTING POINT –3,410 ° C– TARGET HEATED TO 2,000° C

x ray production1
X-RAY PRODUCTION
  • BREMSSTRAHLUNG RADIATION
  • CHARACTERISTIC RADIATION
bremsstrahlung radiation
BREMSSTRAHLUNG RADIATION

If an incoming free electron gets close to the nucleus of a target atom, the strong electric field of the nucleus will attract the electron, thus changing direction and speed of the electron. The Electron looses energy which will be emitted as an X-ray photon. The energy of this photon will depend on the degree of interaction between nucleus and electron, i.e. the passing distance. Several subsequent interactions between one and the same electron and different nuclei are possible. X-rays originating from this process are called bremsstrahlung. Bemsstrahlung is a German word directly describing the process: "Strahlung" means "radiation", and "Bremse" means "brake

brems radiation is
BREMS RADIATION IS:

POLYENERGETIC !

90% OF X-RAYS ARE PRODUCED THROUGH BREMS

INTERACTIONS WHEN 80-100 KVP APPLIED

characteristic x rays
Characteristic X-rays

The high energy electron can also cause an electron close to the nucleus in a metal atom to be knocked out from its place. This vacancy is filled by an electron further out from the nucleus. The well defined difference in binding energy, characteristic of the material, is emitted as a monoenergetic photon. When detected this X-ray photon gives rise to a characteristic X-ray line in the energy spectrum.

characteristic radiation
Characteristic Radiation

KE OF PROJECTILE ELECTRON > BINDING ENERGYORBITAL ELECTRON

tungsten 74
TUNGSTEN-74

BINDING ENERGIES

OF DIFFERENT SHELL ELECTRONS

K-70 KEV

L-12 KEV

M-2.8 KEV

characteristic x rays1
CHARACTERISTIC X-RAYS

L

K

70-12 = 58 keV

70-3 = 67 keV

M

K

M

12-3 = 9 keV

L

each characteristic radiation ex k to l transfer is
EACH CHARACTERISTIC RADIATION ( ex. K TO L TRANSFER) IS:

MONOENERGETIC !

THERE ARE MANY

CHARACTERISTIC RADIATION

PRODUCED IN ONE ATOM

THEREFORE CHARACTERISTIC

RADIATION

IS ALSO POLYENERGETIC !

x rays production an inefficient process
X-RAYS PRODUCTION AN INEFFICIENT PROCESS

80 KVP

99.4% HEAT 0.6% X-RAYS

efficiency of x ray production
% EFFICIENCY OF X-RAY PRODUCTION

% EFFICIENCY= K * Z * kVp

K = 1 * 10-4

x ray emission
X-RAY EMISSION
  • ISOTROPICAL- IN EVERY DIRECTION
off focus radiation
OFF-FOCUS RADIATION

USEFUL

OFF-FOCUS

ad