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Transcript of Linac Dental
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Accelerator
sumarsono
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Linear particle accelerator (disebut jugaLINAC) adalah instrumentasi untuk percepatan(acceleration) dari partikel subatomic.
Particle accelerator memiliki banyak aplikasi,salah satunya adalah dibidang medik untukmembangkitkan sinar-X berenergi tinggi bagikeperluan terapi (radioterapi). Desain pesawatlinac tergantung jenis partikel yang dipercepat:electron, proton atau ion. Jangkauan ukuran dariseukuran cathode ray tube hingga sepanjang 2-
mil Stanford Linear Accelerator Center diCalifornia. ; Untuk keperluan radioterapi 0.5 1.5 meter
http://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Stanford_Linear_Accelerator_Centerhttp://en.wikipedia.org/wiki/Californiahttp://en.wikipedia.org/wiki/Californiahttp://en.wikipedia.org/wiki/Stanford_Linear_Accelerator_Centerhttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/Electron -
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Alinear particle accelerator consists of the following
elements:
Sumber partikel.
The design of the source depends on the particlethat is being accelerated. Electrons are
generated by a cold cathode, a hot cathode, aphotocathode, or RF ion sources. Protons aregenerated in an ion source, which can havemany different designs. If heavier particles areto be accelerated, (e.g. uraniumions), aspecialized ion source is needed.
A high voltage source for the initial injection ofparticles.
http://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Cold_cathodehttp://en.wikipedia.org/wiki/Hot_cathodehttp://en.wikipedia.org/wiki/Photocathodehttp://en.wikipedia.org/wiki/RF_antenna_ion_sourcehttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/Ion_sourcehttp://en.wikipedia.org/wiki/Uraniumhttp://en.wikipedia.org/wiki/Ionshttp://en.wikipedia.org/wiki/Ion_sourcehttp://en.wikipedia.org/wiki/Ion_sourcehttp://en.wikipedia.org/wiki/Ionshttp://en.wikipedia.org/wiki/Uraniumhttp://en.wikipedia.org/wiki/Ion_sourcehttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/RF_antenna_ion_sourcehttp://en.wikipedia.org/wiki/Photocathodehttp://en.wikipedia.org/wiki/Hot_cathodehttp://en.wikipedia.org/wiki/Cold_cathodehttp://en.wikipedia.org/wiki/Electron -
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A hollow pipe vacuum chamber. Thelength will vary with the application. If thedevice is used for the production of X-rays
for inspection or therapy the pipe may beonly 0.5 to 1.5 meters long. If the deviceis to be an injector for a synchrotron itmay be about ten meters long. If thedevice is used as the primary acceleratorfor nuclear particle investigations, it maybe several thousand meters long.
Within the chamber, electrically isolatedcylindrical electrodes whose length varieswith the distance along the pipe
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One or more sources of radio frequency energy, usedto energize the cylindrical electrodes. A very highpower accelerator will use one source for each
electrode. The sources must operate at precise power,frequency and phase appropriate to the particle typeto be accelerated to obtain maximum device power
An appropriate target. If electrons are accelerated to
produce X-rays then a water cooled tungsten target isused. Various target materials are used when protonsor other nuclei are accelerated, depending upon thespecific investigation. For particle-to-particle collision
investigations the beam may be directed to a pair ofstorage rings, with the particles kept within the ringby magnetic fields. The beams may then be extractedfrom the storage rings to create head on particle
collisions.
http://en.wikipedia.org/wiki/X-rayshttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/Protonhttp://en.wikipedia.org/wiki/X-rayshttp://en.wikipedia.org/wiki/X-rayshttp://en.wikipedia.org/wiki/X-rays -
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Blok Diagram Linac
Powe supply
modulator
Electron gun
Magnetron
Or
Klystron
Treatment head
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Types of AcceleratorThe acceleration of the particles can be
made with three general methods: Electrostatically: The particles are accelerated
the electric field between two different fixedpotentials. Examples include theVan de Graaf,Pelletron and Tadem accelerators.
Induction a pulsed voltage is applied aroundmagnetic cores. The electric field produced bythis voltage is used to accelerate the particles.
Radio frequensi RF : The electric field
component ofradio waves acclerate particlesinside a partially closed conducting cavity actingas a RF cavity resonator. Examples incude thetravelling wave, Alvarez and Wideroe cavity typeaccelerators.
http://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Van_de_Graaf_generatorhttp://en.wikipedia.org/wiki/Pelletronhttp://en.wikipedia.org/wiki/Particle_acceleratorhttp://en.wikipedia.org/wiki/Van_de_Graaf_generatorhttp://en.wikipedia.org/wiki/Pelletronhttp://en.wikipedia.org/wiki/Particle_acceleratorhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Radio_waveshttp://en.wikipedia.org/wiki/Radio_waveshttp://en.wikipedia.org/wiki/Cavity_resonatorhttp://en.wikipedia.org/wiki/Cavity_resonatorhttp://en.wikipedia.org/wiki/Cavity_resonatorhttp://en.wikipedia.org/wiki/Radio_waveshttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Particle_acceleratorhttp://en.wikipedia.org/wiki/Pelletronhttp://en.wikipedia.org/wiki/Van_de_Graaf_generatorhttp://en.wikipedia.org/wiki/Electric_field -
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AdvantagesMedical linacs utilise monoenergetic
electron beams between 4 and 25 MeV,giving an x-ray output with a spectrum ofenergies up to and including the electronenergy. The x-rays treat both benign andmalignant disease. The reliability,flexibility and accuracy of the radiationbeam produced has largely supplanted
cobalt therapy as a treatment tool. Inaddition, the device can simply bepowered off when not in use; there is nosource requiring heavy shielding.
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Disadvantages The device length limits the locations where one may be
placed. A great number of driver devices and their associated
power supplies are required, increasing the constructionand maintenance expense of this portion
If the walls of the accelerating cavities are made ofnormally conducting material and the accelerating fieldsare large, the wall resistivity converts electric energy intoheat quickly. On the other hand superconductors havevarious limits and are too expensive for very largeaccelerators. Therefore, high energy accelerators suchas SLAC, still the longest in the world, (in its various
generations) are run in short pulses, limiting the averagecurrent output and forcing the experimental detectors tohandle data coming in short bursts.
http://en.wikipedia.org/wiki/SLAChttp://en.wikipedia.org/wiki/SLAChttp://en.wikipedia.org/wiki/SLAC -
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Radioterapi
Pengobatan kanker (tumor ganas) denganradiasi.
Tujuan :
- Menyembuhkan (primer)
- Penunjang / kombinasi terapi
- Meringankan / memperlambatpertumbuhan tumor
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Teknik Radioterapi
Suatu target diberi radiasi sebesar x rad
Untuk mecapai dosis target dilakukansecara bertahap (y kali) pada tempat yangberbeda-beda sehingga targetmemperoleh radiasi sebasar x rad namun
jaringan organ normal disekitarnya di
upayakan tidak dipengaruhi.
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Dental unit dan Pesawat
panoramik
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Panoramik
Mengambilgambar gigi-geligisecara
tomografi/irisan Seluruh gigi
terliputi
FILM
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