SlideShare a Scribd company logo
1 of 30
LINEAR ACCELERATOR
1
SAILAKSHMI . P
MSc. Radiation Physics
University of Calicut
I N S L I D E S
 Introduction
 History
 Components
1. Injection system.
2. RF system.
3. Auxiliary system.
4. Beam transport system.
5. Beam collimation and Monitoring system.
 Treatment couch
2
INTRODUCTION
WHAT IS LINEAR ACCELERATOR?
 A linear particle accelerator is a type
of accelerator that greatly increases
the velocity of charged subatomic
particles or ions by subjecting
the charged particles to a series
of oscillating electric potentials along
a linear beamline.
 Linear accelerator is the device most
commonly used for external beam
radiation treatments ( teletherapy) .
3
HISTORY
 In the late 1940s, the idea of using
linear accelerator in the medical
application become interested .
Medical Linear Accelerators have
been in clinical use since the early
1950s.
 During the past 70 years medical
linacs have gone through 5 distinct
generations. Each of the 5
generations introduced new
features.
4
HISTORY
1. Low energy photons (4-8 MV)
straight through beam, fixed flattening filter, external wedges, symmetric
jaws, single transmission ionization chamber, isocentric mounting.
2. Medium energy photons (10-15MV) and electrons
bent beam, movable target and flattening filter, dual transmission ionization
chamber, electron cones.
3. High energy photons (18-25MV) and electrons
dual photon energy and multiple electron energies, achromatic bending
magnet, dual scattering foils or scanned electron pencil beam, automatic
wedge selector, independent collimator jaws.
5
HISTORY
4. High energy photons and electrons
computer controlled operation, dynamic wedge, electronic portal
imaging device, multileaf collimator.
5. High energy photons and electrons
photon beam intensity modulation with multileaf collimator (MLC) , full
dynamic conformal dose delivery with intensity modulated beams
produced with an MLC.
6
HOW DOES IT WORK ?
• The linear accelerator uses microwave technology to accelerate electrons
in a part of the accelerator called the "wave guide", then allows these
electrons to collide with a heavy metal target. As a result of the collisions,
high-energy photons are produced from the target.
• The high energy x-rays will be directed to the patient’s tumor and shaped
as they exit the machine to conform to the shape of the patient’s tumor.
Radiation can be delivered to the tumor from any angle by rotating the
gantry and moving the treatment couch.
7
8
The Main Operating Components Of A Medical
Linac Usually Grouped Into 5 Classes :
1. Injection system.
2. RF system.
3. Auxiliary system.
4. Beam transport system.
5. Beam collimation and Monitoring system.
9
10
INJECTION SYSTEM
ELECTRON GUN
Electrons are produced by thermionic emission from a heated
cathode .
Two basic types of electron gun exist :
THE DIODE TYPE
In the diode gun the voltage applied to the cathode is pulsed, so producing
bunches of electrons rather than a continuous stream.
THE TRIODE TYPE
Produces discrete bunches of electron by introducing a grid , between cathode
and anode.
The injection of electrons into the accelerating waveguide is then controlled by
voltage pulses, which are applied to the grid and must be synchronized with the
pulses applied to the microwave generator.
11
RF SYSTEM
• The electrons are accelerated in the accelerating wave guide using
high power RF fields. Which are set up in the accelerating wave guide
by microwave radiation.
• This radiation is produced by microwave generators that are either
magnetrons or klystrons.
12
RF SYSTEM
• It produces microwave required
for electron acceleration.
• Function as a high frequency
oscillator.
• Peak power up to 5 MW can be
produced by magnetrons.
MAGNETRON
13
RF SYSTEM
KLYSTRON
• It acts as a RF power amplifier .
• Peak power on the order of 7MW
or higher.
• Mainly using in high energy linacs
14
ELECTRON BEAM TRANSPORT
• It consists of the evacuated drift
tubes and bending magnets,
which are used in transporting
the electron beam from the
accelerating waveguide to the x
ray target or to the exit window
for electron beam therapy.
• Steering and focusing coils
installed on the accelerating
wave guide are usually linked
with the electron transport
system.
15
ACCELERATING WAVEGUIDE
• There are two different types
of accelerating wave guides
they are ;
• Standing or stationary wave
accelerator.
• Traveling wave accelerator.
16
ACCELERATING WAVEGUIDE
TRAVELLING WAVE GUIDE
• In this Microwaves absorbed
at the end of the wave guide
or exit the waveguide to be
absorbed in a resistive load or
fed back to the input end of
the waveguide.
17
ACCELERATING WAVEGUIDE
STANDING WAVE GUIDE
• Microwaves reflected from
distal surface to produce a
standing wave.
• Each end of the wave guide is
terminated with a conducting
disk to reflect the microwave
power.
18
BENDING MAGNET
Three systems for electron beam bending
90° bending 270° bending 112.5° bending
19
BEAM COLLIMATION AND MONITORING
SYSTEM
 Target
 Primary collimator
 Flattening filter or scattering foils
 Dual Ion chamber
 Secondary collimator
 Multi leaf collimator
20
TARGET
• There are 3 types of target : Thin,
Intermediate, and Thick.
• In linac we use thick targets due to
some practical reasons.
• Efficiency for photon production in
thick target is proportional to the
atomic number Z of the target
material.
• In medical linacs high Z targets (eg :
Pb) would produce beams with
highest efficiency.
21
PRIMARY COLLIMATOR
• It defines the largest available
circular field size and is
essentially a conical opening
projecting into a tungsten
shielding block.
• One end of the conical opening
of the collimator projecting onto
edges of the target and the
other to the flattening filter.
22
FLATTENING FILTER
• The photon dose distribution
produced by a linac is strongly
forward peaked.
• To make the beam intensity
uniform across the field, a
flattening filter is inserted in
the beam.
• The filter is usually made of
Pb, although tungsten,
uranium, steel , aluminum or a
combination has also
suggested.
23
DUAL IONIZATION CHAMBER
• The flattened beam is incident on the dose
monitoring chambers.
• The monitoring system consist of several
ion chambers or a single chamber with
multiple plates.
• The chambers are usually transmission
type, i.e., flat parallel plate or cylindrical
thimble chamber is used in some linacs.
24
SCATTERING FOILS
• In the electron mode of linac
operation , the beam instead of
striking the target , is made to
strike an electron scattering foil
to spread the beam as well as get
a uniform electron fluence across
the treatment field.
• It consist of a thin metallic foil,
usually of lead.
25
SECONDARY COLLIMATOR
• It consist of four blocks, two forming
the upper and two forming the lower
jaws.
• Provide rectangular or square field at
the linac isocenter.
• Usually made of lead or tungsten.
26
MULTILEAF COLLIMATOR
• Using MLC’s we can conform the
treatment fields to the tumor
volume.
• The number of leaves in the
commercial MLC’s are steadily
increasing.
• leaves: 82, 120,160 & width: 1cm
and 1.5 to 6mm is currently
available.
• Each leaves is controlled by
computer controlled motors.
27
28
TREATMENT COUCH
 The treatment couch is the area on which
patient’s are positioned to receive their
radiation treatment, and it has the ability
to move
• up/ down
• Right /left
• In/out
• Hexapod (currently 6 degrees of motions
are available)
 The linac couch 6D displacements
are vertical, longitudinal, lateral, yaw, roll
and pitch
29
30

More Related Content

What's hot

Physics and Operation of Linear Accelerator
Physics and Operation of Linear AcceleratorPhysics and Operation of Linear Accelerator
Physics and Operation of Linear Acceleratorsailakshmi pullookkara
 
Beam Modification in Radiotherapy
Beam Modification in RadiotherapyBeam Modification in Radiotherapy
Beam Modification in RadiotherapySantam Chakraborty
 
Linac- A Practical Approach
Linac- A Practical Approach Linac- A Practical Approach
Linac- A Practical Approach Aaditya Sinha
 
planning systems in radiotherapy
 planning systems in radiotherapy planning systems in radiotherapy
planning systems in radiotherapyfondas vakalis
 
Interaction of ionising radiation
Interaction of ionising radiationInteraction of ionising radiation
Interaction of ionising radiationKiran Ramakrishna
 
Linear accelerator
Linear acceleratorLinear accelerator
Linear acceleratorNeena John
 
Isodose curves RADIATION ONCOLOGY
Isodose curves RADIATION ONCOLOGYIsodose curves RADIATION ONCOLOGY
Isodose curves RADIATION ONCOLOGYPaul George
 
IMMOBILIZATION IN RADIOTHERAPY
IMMOBILIZATION IN RADIOTHERAPYIMMOBILIZATION IN RADIOTHERAPY
IMMOBILIZATION IN RADIOTHERAPYSubrata Roy
 
Beam Directed Radiotherapy - methods and principles
Beam Directed Radiotherapy - methods and principlesBeam Directed Radiotherapy - methods and principles
Beam Directed Radiotherapy - methods and principlesSantam Chakraborty
 
Beam modification devices
Beam modification devicesBeam modification devices
Beam modification devicesVibhay Pareek
 
Basic principle of gamma camera
Basic principle of gamma cameraBasic principle of gamma camera
Basic principle of gamma cameraUpakar Paudel
 
Medical linear accelerator
Medical linear acceleratorMedical linear accelerator
Medical linear acceleratorAmin Amin
 
Role of immobilisation and devices in radiotherapy
Role of immobilisation and devices in radiotherapyRole of immobilisation and devices in radiotherapy
Role of immobilisation and devices in radiotherapySwarnita Sahu
 
Principles of beam direction and use of simulators
Principles of beam direction and use of simulators Principles of beam direction and use of simulators
Principles of beam direction and use of simulators Anil Gupta
 
Patient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy PlanningPatient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy PlanningSubhash Thakur
 

What's hot (20)

Physics and Operation of Linear Accelerator
Physics and Operation of Linear AcceleratorPhysics and Operation of Linear Accelerator
Physics and Operation of Linear Accelerator
 
Radiotherapy Equipment
Radiotherapy EquipmentRadiotherapy Equipment
Radiotherapy Equipment
 
Linac
LinacLinac
Linac
 
Beam Modification in Radiotherapy
Beam Modification in RadiotherapyBeam Modification in Radiotherapy
Beam Modification in Radiotherapy
 
Linac- A Practical Approach
Linac- A Practical Approach Linac- A Practical Approach
Linac- A Practical Approach
 
Linear Accelerators
Linear AcceleratorsLinear Accelerators
Linear Accelerators
 
planning systems in radiotherapy
 planning systems in radiotherapy planning systems in radiotherapy
planning systems in radiotherapy
 
Interaction of ionising radiation
Interaction of ionising radiationInteraction of ionising radiation
Interaction of ionising radiation
 
Linear accelerator
Linear acceleratorLinear accelerator
Linear accelerator
 
Isodose curves RADIATION ONCOLOGY
Isodose curves RADIATION ONCOLOGYIsodose curves RADIATION ONCOLOGY
Isodose curves RADIATION ONCOLOGY
 
IMMOBILIZATION IN RADIOTHERAPY
IMMOBILIZATION IN RADIOTHERAPYIMMOBILIZATION IN RADIOTHERAPY
IMMOBILIZATION IN RADIOTHERAPY
 
Beam Directed Radiotherapy - methods and principles
Beam Directed Radiotherapy - methods and principlesBeam Directed Radiotherapy - methods and principles
Beam Directed Radiotherapy - methods and principles
 
Dosimetry concepts and dosimeters
Dosimetry concepts and dosimetersDosimetry concepts and dosimeters
Dosimetry concepts and dosimeters
 
Beam modification devices
Beam modification devicesBeam modification devices
Beam modification devices
 
Basic principle of gamma camera
Basic principle of gamma cameraBasic principle of gamma camera
Basic principle of gamma camera
 
Medical linear accelerator
Medical linear acceleratorMedical linear accelerator
Medical linear accelerator
 
Role of immobilisation and devices in radiotherapy
Role of immobilisation and devices in radiotherapyRole of immobilisation and devices in radiotherapy
Role of immobilisation and devices in radiotherapy
 
Thermoluminesence dosimetry
Thermoluminesence dosimetryThermoluminesence dosimetry
Thermoluminesence dosimetry
 
Principles of beam direction and use of simulators
Principles of beam direction and use of simulators Principles of beam direction and use of simulators
Principles of beam direction and use of simulators
 
Patient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy PlanningPatient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy Planning
 

Viewers also liked

LINEAR ACCELARATOR
LINEAR ACCELARATORLINEAR ACCELARATOR
LINEAR ACCELARATORWaqar Ahmed
 
Linear accelerator linac
Linear accelerator linacLinear accelerator linac
Linear accelerator linacSyed Hammad .
 
Linear accelator
Linear accelatorLinear accelator
Linear accelatorSUST\RICK
 
Linear Accelerator Acceptance, Commissioning and Annual QA
Linear Accelerator Acceptance, Commissioning and Annual QALinear Accelerator Acceptance, Commissioning and Annual QA
Linear Accelerator Acceptance, Commissioning and Annual QAMiami Cancer Institute
 
Quality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHXQuality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHXSohail Qureshi
 
Radiation Therapy
Radiation TherapyRadiation Therapy
Radiation Therapykathrnrt
 
Quality Management Systems in Radiotherapy based on ISO 9001 standard
Quality Management Systems in Radiotherapy based on ISO 9001 standardQuality Management Systems in Radiotherapy based on ISO 9001 standard
Quality Management Systems in Radiotherapy based on ISO 9001 standardVal Antoff
 
Visualizing Radiation Physics Concepts with photon electron particle tracks
Visualizing Radiation Physics Concepts with photon electron particle tracksVisualizing Radiation Physics Concepts with photon electron particle tracks
Visualizing Radiation Physics Concepts with photon electron particle tracksShahid Naqvi
 
Radiation therapy
Radiation therapyRadiation therapy
Radiation therapyRad Tech
 
CHARGE PARTICLE ACCELERATORCharge particle accelerator
CHARGE PARTICLE ACCELERATORCharge particle acceleratorCHARGE PARTICLE ACCELERATORCharge particle accelerator
CHARGE PARTICLE ACCELERATORCharge particle acceleratorSYED SHAHEEN SHAH
 
Particle accelerator
Particle acceleratorParticle accelerator
Particle acceleratorChen Siyuan
 

Viewers also liked (20)

linear accelerator
linear acceleratorlinear accelerator
linear accelerator
 
LINEAR ACCELARATOR
LINEAR ACCELARATORLINEAR ACCELARATOR
LINEAR ACCELARATOR
 
Linear accelerator linac
Linear accelerator linacLinear accelerator linac
Linear accelerator linac
 
Linac
LinacLinac
Linac
 
Linear accelator
Linear accelatorLinear accelator
Linear accelator
 
Linear Accelerator Acceptance, Commissioning and Annual QA
Linear Accelerator Acceptance, Commissioning and Annual QALinear Accelerator Acceptance, Commissioning and Annual QA
Linear Accelerator Acceptance, Commissioning and Annual QA
 
21 Ex Qa
21 Ex Qa21 Ex Qa
21 Ex Qa
 
Cobalt
CobaltCobalt
Cobalt
 
Cobalt 60
Cobalt 60Cobalt 60
Cobalt 60
 
Linac presentation
Linac presentationLinac presentation
Linac presentation
 
IMPROVISED RADIOTHERAPY TECHNIQUES IN TELE COBALT WITHOUT MLC
IMPROVISED RADIOTHERAPY TECHNIQUES IN TELE COBALT WITHOUT MLCIMPROVISED RADIOTHERAPY TECHNIQUES IN TELE COBALT WITHOUT MLC
IMPROVISED RADIOTHERAPY TECHNIQUES IN TELE COBALT WITHOUT MLC
 
Quality Assurance in Radiotherapy
Quality Assurance in RadiotherapyQuality Assurance in Radiotherapy
Quality Assurance in Radiotherapy
 
Quality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHXQuality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHX
 
Radiation Therapy
Radiation TherapyRadiation Therapy
Radiation Therapy
 
LINAC
LINACLINAC
LINAC
 
Quality Management Systems in Radiotherapy based on ISO 9001 standard
Quality Management Systems in Radiotherapy based on ISO 9001 standardQuality Management Systems in Radiotherapy based on ISO 9001 standard
Quality Management Systems in Radiotherapy based on ISO 9001 standard
 
Visualizing Radiation Physics Concepts with photon electron particle tracks
Visualizing Radiation Physics Concepts with photon electron particle tracksVisualizing Radiation Physics Concepts with photon electron particle tracks
Visualizing Radiation Physics Concepts with photon electron particle tracks
 
Radiation therapy
Radiation therapyRadiation therapy
Radiation therapy
 
CHARGE PARTICLE ACCELERATORCharge particle accelerator
CHARGE PARTICLE ACCELERATORCharge particle acceleratorCHARGE PARTICLE ACCELERATORCharge particle accelerator
CHARGE PARTICLE ACCELERATORCharge particle accelerator
 
Particle accelerator
Particle acceleratorParticle accelerator
Particle accelerator
 

Similar to Linear Accelerator

LINEAR ACCELERATOR PRINCIPAL AND WORKING
LINEAR ACCELERATOR PRINCIPAL AND WORKINGLINEAR ACCELERATOR PRINCIPAL AND WORKING
LINEAR ACCELERATOR PRINCIPAL AND WORKINGKrishan Murari Yadav
 
Brief description of Linear accelerator machine
Brief description of Linear accelerator machine Brief description of Linear accelerator machine
Brief description of Linear accelerator machine Dr. Pallavi Jain
 
LINAC- LINEAR ACCELERATOR
LINAC- LINEAR ACCELERATORLINAC- LINEAR ACCELERATOR
LINAC- LINEAR ACCELERATORMariya Kikali
 
Madical liner accelartaer. Morden radiotherapy
Madical liner accelartaer. Morden radiotherapyMadical liner accelartaer. Morden radiotherapy
Madical liner accelartaer. Morden radiotherapyHimanshuYadav588266
 
CLINICAL RADIATION GENERATORS
CLINICAL RADIATION GENERATORS CLINICAL RADIATION GENERATORS
CLINICAL RADIATION GENERATORS Sathish Kumar
 
Clinical Generators in Radiotherapy by Dr.Avilash.pptx
Clinical Generators in Radiotherapy by Dr.Avilash.pptxClinical Generators in Radiotherapy by Dr.Avilash.pptx
Clinical Generators in Radiotherapy by Dr.Avilash.pptxAbhilashBanerjee3
 
Radiation physics
Radiation physicsRadiation physics
Radiation physicsDr Kumar
 
Radiation Generating equipments of LINAC
Radiation Generating equipments of LINACRadiation Generating equipments of LINAC
Radiation Generating equipments of LINACSubhrenduGhosh1
 
DLA 1204 Radiation Physics
DLA 1204 Radiation PhysicsDLA 1204 Radiation Physics
DLA 1204 Radiation PhysicsKatieHenkel1
 
Production of x rays
Production of x raysProduction of x rays
Production of x raysDeepaGautam
 
Ultra violet spectrometer
Ultra violet spectrometerUltra violet spectrometer
Ultra violet spectrometeranshu singh
 
circuit diagram.pptx
circuit diagram.pptxcircuit diagram.pptx
circuit diagram.pptxFAYAZ KHAWAJA
 
Clinical radiation generators
Clinical radiation generatorsClinical radiation generators
Clinical radiation generatorsManish Sandhu
 

Similar to Linear Accelerator (20)

LINEAR ACCELERATOR PRINCIPAL AND WORKING
LINEAR ACCELERATOR PRINCIPAL AND WORKINGLINEAR ACCELERATOR PRINCIPAL AND WORKING
LINEAR ACCELERATOR PRINCIPAL AND WORKING
 
Brief description of Linear accelerator machine
Brief description of Linear accelerator machine Brief description of Linear accelerator machine
Brief description of Linear accelerator machine
 
LINAC- LINEAR ACCELERATOR
LINAC- LINEAR ACCELERATORLINAC- LINEAR ACCELERATOR
LINAC- LINEAR ACCELERATOR
 
Basic of medical linac
Basic of medical linacBasic of medical linac
Basic of medical linac
 
M LINAC JJ.pptx
M LINAC JJ.pptxM LINAC JJ.pptx
M LINAC JJ.pptx
 
Madical liner accelartaer. Morden radiotherapy
Madical liner accelartaer. Morden radiotherapyMadical liner accelartaer. Morden radiotherapy
Madical liner accelartaer. Morden radiotherapy
 
CLINICAL RADIATION GENERATORS
CLINICAL RADIATION GENERATORS CLINICAL RADIATION GENERATORS
CLINICAL RADIATION GENERATORS
 
Clinical Generators in Radiotherapy by Dr.Avilash.pptx
Clinical Generators in Radiotherapy by Dr.Avilash.pptxClinical Generators in Radiotherapy by Dr.Avilash.pptx
Clinical Generators in Radiotherapy by Dr.Avilash.pptx
 
Radiation physics
Radiation physicsRadiation physics
Radiation physics
 
Radiation Generating equipments of LINAC
Radiation Generating equipments of LINACRadiation Generating equipments of LINAC
Radiation Generating equipments of LINAC
 
DLA 1204 Radiation Physics
DLA 1204 Radiation PhysicsDLA 1204 Radiation Physics
DLA 1204 Radiation Physics
 
Linear accelerator.pptx
Linear accelerator.pptxLinear accelerator.pptx
Linear accelerator.pptx
 
Linear accelerator
Linear acceleratorLinear accelerator
Linear accelerator
 
U.V Spectroscopy.
U.V Spectroscopy.U.V Spectroscopy.
U.V Spectroscopy.
 
Production of x rays
Production of x raysProduction of x rays
Production of x rays
 
Ultra violet spectrometer
Ultra violet spectrometerUltra violet spectrometer
Ultra violet spectrometer
 
circuit diagram.pptx
circuit diagram.pptxcircuit diagram.pptx
circuit diagram.pptx
 
Lecture (2)
Lecture (2)Lecture (2)
Lecture (2)
 
Linear Accelerators.pptx
Linear Accelerators.pptxLinear Accelerators.pptx
Linear Accelerators.pptx
 
Clinical radiation generators
Clinical radiation generatorsClinical radiation generators
Clinical radiation generators
 

Recently uploaded

Education and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxEducation and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxraviapr7
 
The basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptxThe basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptxheathfieldcps1
 
HED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdfHED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdfMohonDas
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfTechSoup
 
The Singapore Teaching Practice document
The Singapore Teaching Practice documentThe Singapore Teaching Practice document
The Singapore Teaching Practice documentXsasf Sfdfasd
 
Benefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationBenefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationMJDuyan
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17Celine George
 
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptxClinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptxraviapr7
 
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptxPISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptxEduSkills OECD
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxDr. Santhosh Kumar. N
 
How to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 SalesHow to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 SalesCeline George
 
Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...raviapr7
 
2024.03.23 What do successful readers do - Sandy Millin for PARK.pptx
2024.03.23 What do successful readers do - Sandy Millin for PARK.pptx2024.03.23 What do successful readers do - Sandy Millin for PARK.pptx
2024.03.23 What do successful readers do - Sandy Millin for PARK.pptxSandy Millin
 
CapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptxCapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptxCapitolTechU
 
Philosophy of Education and Educational Philosophy
Philosophy of Education  and Educational PhilosophyPhilosophy of Education  and Educational Philosophy
Philosophy of Education and Educational PhilosophyShuvankar Madhu
 
CAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxCAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxSaurabhParmar42
 
How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17Celine George
 
Practical Research 1: Lesson 8 Writing the Thesis Statement.pptx
Practical Research 1: Lesson 8 Writing the Thesis Statement.pptxPractical Research 1: Lesson 8 Writing the Thesis Statement.pptx
Practical Research 1: Lesson 8 Writing the Thesis Statement.pptxKatherine Villaluna
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxraviapr7
 

Recently uploaded (20)

Education and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxEducation and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptx
 
The basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptxThe basics of sentences session 10pptx.pptx
The basics of sentences session 10pptx.pptx
 
HED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdfHED Office Sohayok Exam Question Solution 2023.pdf
HED Office Sohayok Exam Question Solution 2023.pdf
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
 
The Singapore Teaching Practice document
The Singapore Teaching Practice documentThe Singapore Teaching Practice document
The Singapore Teaching Practice document
 
Benefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationBenefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive Education
 
Finals of Kant get Marx 2.0 : a general politics quiz
Finals of Kant get Marx 2.0 : a general politics quizFinals of Kant get Marx 2.0 : a general politics quiz
Finals of Kant get Marx 2.0 : a general politics quiz
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17
 
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptxClinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
 
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptxPISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptx
 
How to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 SalesHow to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 Sales
 
Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...
 
2024.03.23 What do successful readers do - Sandy Millin for PARK.pptx
2024.03.23 What do successful readers do - Sandy Millin for PARK.pptx2024.03.23 What do successful readers do - Sandy Millin for PARK.pptx
2024.03.23 What do successful readers do - Sandy Millin for PARK.pptx
 
CapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptxCapTechU Doctoral Presentation -March 2024 slides.pptx
CapTechU Doctoral Presentation -March 2024 slides.pptx
 
Philosophy of Education and Educational Philosophy
Philosophy of Education  and Educational PhilosophyPhilosophy of Education  and Educational Philosophy
Philosophy of Education and Educational Philosophy
 
CAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxCAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptx
 
How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17
 
Practical Research 1: Lesson 8 Writing the Thesis Statement.pptx
Practical Research 1: Lesson 8 Writing the Thesis Statement.pptxPractical Research 1: Lesson 8 Writing the Thesis Statement.pptx
Practical Research 1: Lesson 8 Writing the Thesis Statement.pptx
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptx
 

Linear Accelerator

  • 1. LINEAR ACCELERATOR 1 SAILAKSHMI . P MSc. Radiation Physics University of Calicut
  • 2. I N S L I D E S  Introduction  History  Components 1. Injection system. 2. RF system. 3. Auxiliary system. 4. Beam transport system. 5. Beam collimation and Monitoring system.  Treatment couch 2
  • 3. INTRODUCTION WHAT IS LINEAR ACCELERATOR?  A linear particle accelerator is a type of accelerator that greatly increases the velocity of charged subatomic particles or ions by subjecting the charged particles to a series of oscillating electric potentials along a linear beamline.  Linear accelerator is the device most commonly used for external beam radiation treatments ( teletherapy) . 3
  • 4. HISTORY  In the late 1940s, the idea of using linear accelerator in the medical application become interested . Medical Linear Accelerators have been in clinical use since the early 1950s.  During the past 70 years medical linacs have gone through 5 distinct generations. Each of the 5 generations introduced new features. 4
  • 5. HISTORY 1. Low energy photons (4-8 MV) straight through beam, fixed flattening filter, external wedges, symmetric jaws, single transmission ionization chamber, isocentric mounting. 2. Medium energy photons (10-15MV) and electrons bent beam, movable target and flattening filter, dual transmission ionization chamber, electron cones. 3. High energy photons (18-25MV) and electrons dual photon energy and multiple electron energies, achromatic bending magnet, dual scattering foils or scanned electron pencil beam, automatic wedge selector, independent collimator jaws. 5
  • 6. HISTORY 4. High energy photons and electrons computer controlled operation, dynamic wedge, electronic portal imaging device, multileaf collimator. 5. High energy photons and electrons photon beam intensity modulation with multileaf collimator (MLC) , full dynamic conformal dose delivery with intensity modulated beams produced with an MLC. 6
  • 7. HOW DOES IT WORK ? • The linear accelerator uses microwave technology to accelerate electrons in a part of the accelerator called the "wave guide", then allows these electrons to collide with a heavy metal target. As a result of the collisions, high-energy photons are produced from the target. • The high energy x-rays will be directed to the patient’s tumor and shaped as they exit the machine to conform to the shape of the patient’s tumor. Radiation can be delivered to the tumor from any angle by rotating the gantry and moving the treatment couch. 7
  • 8. 8
  • 9. The Main Operating Components Of A Medical Linac Usually Grouped Into 5 Classes : 1. Injection system. 2. RF system. 3. Auxiliary system. 4. Beam transport system. 5. Beam collimation and Monitoring system. 9
  • 10. 10
  • 11. INJECTION SYSTEM ELECTRON GUN Electrons are produced by thermionic emission from a heated cathode . Two basic types of electron gun exist : THE DIODE TYPE In the diode gun the voltage applied to the cathode is pulsed, so producing bunches of electrons rather than a continuous stream. THE TRIODE TYPE Produces discrete bunches of electron by introducing a grid , between cathode and anode. The injection of electrons into the accelerating waveguide is then controlled by voltage pulses, which are applied to the grid and must be synchronized with the pulses applied to the microwave generator. 11
  • 12. RF SYSTEM • The electrons are accelerated in the accelerating wave guide using high power RF fields. Which are set up in the accelerating wave guide by microwave radiation. • This radiation is produced by microwave generators that are either magnetrons or klystrons. 12
  • 13. RF SYSTEM • It produces microwave required for electron acceleration. • Function as a high frequency oscillator. • Peak power up to 5 MW can be produced by magnetrons. MAGNETRON 13
  • 14. RF SYSTEM KLYSTRON • It acts as a RF power amplifier . • Peak power on the order of 7MW or higher. • Mainly using in high energy linacs 14
  • 15. ELECTRON BEAM TRANSPORT • It consists of the evacuated drift tubes and bending magnets, which are used in transporting the electron beam from the accelerating waveguide to the x ray target or to the exit window for electron beam therapy. • Steering and focusing coils installed on the accelerating wave guide are usually linked with the electron transport system. 15
  • 16. ACCELERATING WAVEGUIDE • There are two different types of accelerating wave guides they are ; • Standing or stationary wave accelerator. • Traveling wave accelerator. 16
  • 17. ACCELERATING WAVEGUIDE TRAVELLING WAVE GUIDE • In this Microwaves absorbed at the end of the wave guide or exit the waveguide to be absorbed in a resistive load or fed back to the input end of the waveguide. 17
  • 18. ACCELERATING WAVEGUIDE STANDING WAVE GUIDE • Microwaves reflected from distal surface to produce a standing wave. • Each end of the wave guide is terminated with a conducting disk to reflect the microwave power. 18
  • 19. BENDING MAGNET Three systems for electron beam bending 90° bending 270° bending 112.5° bending 19
  • 20. BEAM COLLIMATION AND MONITORING SYSTEM  Target  Primary collimator  Flattening filter or scattering foils  Dual Ion chamber  Secondary collimator  Multi leaf collimator 20
  • 21. TARGET • There are 3 types of target : Thin, Intermediate, and Thick. • In linac we use thick targets due to some practical reasons. • Efficiency for photon production in thick target is proportional to the atomic number Z of the target material. • In medical linacs high Z targets (eg : Pb) would produce beams with highest efficiency. 21
  • 22. PRIMARY COLLIMATOR • It defines the largest available circular field size and is essentially a conical opening projecting into a tungsten shielding block. • One end of the conical opening of the collimator projecting onto edges of the target and the other to the flattening filter. 22
  • 23. FLATTENING FILTER • The photon dose distribution produced by a linac is strongly forward peaked. • To make the beam intensity uniform across the field, a flattening filter is inserted in the beam. • The filter is usually made of Pb, although tungsten, uranium, steel , aluminum or a combination has also suggested. 23
  • 24. DUAL IONIZATION CHAMBER • The flattened beam is incident on the dose monitoring chambers. • The monitoring system consist of several ion chambers or a single chamber with multiple plates. • The chambers are usually transmission type, i.e., flat parallel plate or cylindrical thimble chamber is used in some linacs. 24
  • 25. SCATTERING FOILS • In the electron mode of linac operation , the beam instead of striking the target , is made to strike an electron scattering foil to spread the beam as well as get a uniform electron fluence across the treatment field. • It consist of a thin metallic foil, usually of lead. 25
  • 26. SECONDARY COLLIMATOR • It consist of four blocks, two forming the upper and two forming the lower jaws. • Provide rectangular or square field at the linac isocenter. • Usually made of lead or tungsten. 26
  • 27. MULTILEAF COLLIMATOR • Using MLC’s we can conform the treatment fields to the tumor volume. • The number of leaves in the commercial MLC’s are steadily increasing. • leaves: 82, 120,160 & width: 1cm and 1.5 to 6mm is currently available. • Each leaves is controlled by computer controlled motors. 27
  • 28. 28
  • 29. TREATMENT COUCH  The treatment couch is the area on which patient’s are positioned to receive their radiation treatment, and it has the ability to move • up/ down • Right /left • In/out • Hexapod (currently 6 degrees of motions are available)  The linac couch 6D displacements are vertical, longitudinal, lateral, yaw, roll and pitch 29
  • 30. 30