BBd/2008 1

Energistyrning 4

PRF

PRF

S/H

Power amplifier

ADC Computer program DAC

Pulse transformer

High voltage

Gun

e-

270 degree bending magnet

*

*

BBd/2008 2

Energistyrning 5

Comparator

Up- down

counter PROM DAC

Control

In modulator

Thyratron driver

Target

Ionisation chamber

Accelerator wave-guide

Gun

Thyratron

BBd/2008 3

Energy switch

BBd/2008 4

BBd/2008 5

Böjmagneter

e-

E0 E0-∆E E0+∆E

E0±∆E E0, B N S

e-

E0+∆E

E0-∆E

E0

e-

Target Slits

E0- ∆E

E0+∆E

Magnet

Magnet

Magnet

Magnet 90°

270°

Slalom

BBd/2008 6

e-

e-

e-

E0 E0-∆E E0+∆E

E0

E0

E0±∆E E0, B

B

B

90°-böjmagnet

BBd/2008 7

270°-böjmagnet

Siemens http://www.khulsey.com/oncordet.html

BBd/2008 8

Slalom-böjkammare

BBd/2008 9

Slalom-böjmagnet

BBd/2008 10

Vad finns i strålhuvudet?

BBd/2008 11

e-

e-

MLC MLC

Primary collimator

Primary scatter foil Target Electron

window

Bending magnet

Ionisation chamber Wedge

Lamp

Secondary scatter foils Filter

Collimators

Accelerator wave-guide

Bellow

Bending chamber

Mirror

photons

Strålhuvud; fotoner

BBd/2008 12

e-

e-

MLC MLC

Primary scatter foil Target

Bending magnet

Ionisation chamber Wedge

Lamp

Secondary scatter foils

Filter

Collimators

Accelerator wave-guide

Bellow

Bending chamber

Mirror

photons

Strålhuvud; elektroner

Electron applicator

Sänkt elektronström med en faktor ca 100

Primary collimator

Electron window

BBd/2008 13

Target

1MV

5MV

8MV

2MV

0.5MV Fotoner

Elektroner Energispektrum

e-

N

γ

E

Dålig effektivitet i target

BBd/2008 14

Utjämningsfilter

Energi

N N

Energi

Target

Avstånd i vatten

Avstånd

Profiler på olika djup i patienten

BBd/2008 15

Filterkarusell

BBd/2008 16

Scattering foil 1

Scattering foil 2

Treatment plane

Dubbla spridningsfolier

BBd/2008 17

Diaphragms

a) b)

Double scattering foils Single scattering foil Elektron- applikatorer

BBd/2008 18

Collimators

Scanning magnets

Skannande elektronstråle

BBd/2008 19

Jonisationskammare

BBd/2008 20

+ -

Figure 137.ppt Time

Output voltage

v

Zero

Comparator Reference

Mono stable

Counter

Digital comparator

Set absorb dose register

⇓

⇑

Terminate radiation

v

Dosimetrisystem

BBd/2008 21

300V

Dose-rate

Excess dose-rate

300V Monitoring In software

Dummy dose-rate generator

from software

Integrator and tracker

Ionisation chamber

Control Status latches

Dummy dose-rate generator

from software

Dose-rate

Excess dose-rate

Control

Integrator and tracker

Dose 1 and timer 1 in software

Dose difference in software

Air temperature and air Pressure compensation

Dose 2 and timer 2 in software

Dosimetrisystem

BBd/2008 22

A B C D A C D

Elektroner träffar target

B

Primär- kollimator

Primär- kollimator

BBd/2008 23

Elektronbehandling

N

E

Vid bending- magneten

Ytan av objektet

Vid 2cm djup

BBd/2008 24

Primärkollimering

BBd/2008 25

Sekundärkollimering

BBd/2008 26

Asymmetrisk kollimering och block

Isocenter

BBd/2008 27

Flerbladskollimator (MLC)

BBd/2008 28

Flerbladskollimator (MLC)

Target

Reflector

Mylar mirror

Leaf

Light projector

Mirror

Semi permeable mirror Mirror

Video camera

Patient plane

Video

Monitor Control To leaf motors

Leaf motors

BBd/2008 29

Video camera

Monitor

Demultiplexer

Frame grabber

Multi- plexer

Flexible cables

Leaf motors

Flerbladskollimator (MLC)

BBd/2008 30

Kil

Physical Wedge Flying Wedge Dynamisk Wedge

BBd/2008 31

Kil

BBd/2008 32

Kompensatorer

BBd/2008 33

Bildgivande system (EPID), film

Luft

Vatten

Ben

100%

30%

25%

6MV Rtg

25cm

BBd/2008 34

Jonisationskammare

BBd/2008 35

Epid med fosforskärm och kamera

BBd/2008 36

Elekta iView Cablon Theraview

Siemens Beamview Eliav PORTpro

Indirekt detektering

Direkt detektering

EPID

BBd/2008 37

Aluminium Luftgap

Grafit

Lanex FastTM(Gd2O2S:Tb) Attenuator

Koppar

Fotodioder, amorft kisel

-

-

Rtg

Jöns Jacob Berzelius

Panel från PerkinElmer

BBd/2008 38

CT-system på acceleratorn

BBd/2008 39

Elektas XVI-system

BBd/2008 40

Intensitets Modulerad Radioterapi (IMRT)

www.raysearchlabs.com/ContentPage____159.aspx...

www.nd.edu/~hliu/schoolpage/medical.html

BBd/2008 41

Tomotherapy

BBd/2008 42

BBd/2008 43

GammaKnife och CyberKnife

www.aapm.org/.../SingleTopic/ICyberknife.asp

www.gammaknifestockholm.com

BBd/2008 44

Enhanced dielectric-wall linear accelerator 09/22/1998

Document Type and Number: United States Patent 5811944

Link to this page: http://www.freepatentsonline.com/5811944.html

Abstract: A dielectric-wall linear accelerator is enhanced by a high-voltage,

fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and

insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the

edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly.

Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by

adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

BBd/2008 45

Dielectric Wall Accelerator

www.aapm.org/.../SingleTopic/innovative.asp

Ett pulsat accelerationsfält bildas i asymmetriska Blumlein Korta pulser <10 ns och hög ström >1 kA.

Användning av höggradientisolatorer. Mål: 250 MV på 2.5 m.

BBd/2008 46

Vad är en transmissionsledning?

www.sm.luth.se/~urban/master/Theory/4.html

ε

i(z,t) i(z+Δz,t)

Δz

≈0

≈∞

koaxialkabel

Ekvivalent schema

BBd/2008 47

l

Hög- spännings-

källa (V0) 2R

Om den karakteristiska impedansen Z0 = R

t=0

V0

l t=l/2νp

V0

l t=l/2νp

V0

l t=3l/2νp

V0

l

Single line

V0/2

tid 2l/νp

Utspänning

Slås till vid t=0

längd

Spänning över kabeln

2R

Hur ser spänningen ut längs kabeln?

BBd/2008 48

Blumlein line

Hög- spännings-

källa (V0)

R

V0

tid 3l/νp

Utspänning

l/νp

Induktans

l

ε ε ε ε

Öppnar vid V0

BBd/2008 49

V0

0

V0

0

V0

0

0

t<0

l/νp<t<3l/νp

l

Stackade Blumlein line

ε

ε ε

ε

ε

ε

Kortslut vid t=0

t>3l/νp

= ∑0 ∑0

BBd/2008 50

ε ε

+ - -

ε ε

+ -

ε ε

+ -

- +

ε ε

+ - -

- + V

t

ε ε

+ - - t1 t2 t3 t4 t5

t1 t2 t3 t4 t5

Symmetrisk Blumlein

BBd/2008 51

Höggradientisolator (HGI) Överslag (elektriskt fält)

1000kV/cm HGI

Pulsbredd 104ns

Motsvarande isolator

BBd/2008 52

BBd/2008 53

Gitterstuktur

Silicon Carbide (SiC) crystals

BBd/2008 54 /Caporaso et. al. Silicon Carbide (SiC) crystals

BBd/2008 55 /Caporaso et. al.

Olika längd på ljusledarna => olika tillslagstider

BBd/2008 56

BBd/2008 57

http://www.spi.uni-hannover.de/2001/presentations/lee.pdf

http://www.iee-cambridge.org.uk/arc/seminar04/slides/TeraView.pdf

Fotoledande switch

BBd/2008 58

Fotoledare eller elektronstråle inducerad solid-state switchar. Gaser under högt tryck och flytande dielektriska switchar

dI/dt >1013 A/s

Laser

200kV

Vakuum

https://www.llnl.gov/str/March07/Felton.html

Vakuum ytöverslag-switching

BBd/2008 59

https:/.../2006/SF-06-04-02p.html

Jacqueline McBride/LLNL

Above: Engineer John Harris prepares the vacuum test chamber used to subject high-gradient insulators (HGIs) to high-voltage electric fields. The HGI is the candidate dielectric wall material that will be used for the beam tube in LLNL?s compact proton-beam accelerator. Since it can sustain a very high electric field parallel to its surface, it will be able to provide a high accelerating gradient for the proton beam. Below: A time-integrated open-shutter photo of an HGI flashing over in a 150,000- to 200,000-volt-per-centimeter electric field. Elevating the flashover threshold of these insulators is key to the success of the project.

BBd/2008 60

Proton-Tomotherapy In the Works: Compact, Low-cost Proton Therapy System

It looks like proton therapy will be developed into a compact device, after a technology transfer agreement

between Lawrence Livermore National Laboratory and TomoTherapy Inc., a Madison, Wisconsin company, was announced just a few days ago.

medgadget.com/archives/nuclear_medicine

The DWA, currently being built as a prototype at Livermore, can accelerate protons to up to 100 million electron volts in just a meter. A two-meter DWA could potentially supply protons of sufficiently high energy to treat all tumors, including those buried deep in the body, while fitting in a conventional radiation treatment room.

BBd/2008 61

Intensity Modulated Proton Therapy (IMPT)

www.europhysicsnews.com/.../article6.html

BBd/2008 62

Fixed Field Alternating Gradient

BBd/2008 63

Skillnader mellan olika fabrikat (konventionella linjäracceleratorer)

Elekta Varian Siemens 1. Standing Wave 2. Klystron 3. Dynamisk wedge 4. 2 fotonenergier 5. 270° böjmagnet 6. MLC, 120 blad 7. MLC placerad under kollimatorerna 8. Dubbla spridningsfolier 9. Triod-GUN 10.Modulator med tyratron 11.Sliding window IMRT 12.MLC linjär rörelse 13.Starttid: ca 200 ms 14.Tillverkas i USA 15.Lägger till PRF-pulser

1. Traveling Wave 2. Magnetron 3. Flying wedge 4. 3 fotonenergier 5. Slalom böjmagnet 6. MLC, 80 blad 7. MLC placerad ovanför kollimatorerna 8. Dubbla spridningsfolier 9. Diod-GUN 10.Modulator med tyratron 11.Step and shoot IMRT 12.MLC linjär rörelse 13.Starttid: ca 2 sek 14.Tillverkas i England 15. Ingen doshastighets- reglering

1. Standing Wave 2. Magnetron, klystron 3. Dynamisk wedge 4. 2 fotonenergier 5. 270° böjmagnet 6. MLC, 82 blad 7. MLC placerad under kollimatorerna 8. Dubbla spridningsfolier 9. Diod-GUN 10.Kompakt modulator 11.Sliding window IMRT 12.MLC cirkulär rörelse 13.Starttid ca 200 ms 14.Tillverkas USA 15.Spänningsstyrd oscillator