Transcript PRESENTATION NAME

PL7 – 003
Years of experience in ENEA
Frascati Accelerator LAB
Paolo Nenzi
on behalf of ENEA Frascati Team
AccSys Pleasanton (CA), USA
11 December 2014
Outline
• ENEA Frascati Accelerator lab
• History
• UTAPRAD Technical unit
• A short introduction to hadrontherapy and protontherapy
• Comparison with conventional radiotherapy
• The TOP-IMPLART Project
• Description of the project and LINAC structure
• Project schedule
• Actual Layout of the TOP-IMPLART LINAC
• Development of a single room facility
• Our experience with PL7-003
• Features
• Special requirements
• Modifications
• PL7 Operation: our way
• Remarks
• Discussion
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An introduction on Accelerator
Development in ENEA
The
ENEA
Accelerator
Laboratory is in located in the
ENEA
Frascati
Research
Centre.
It grew up as an extension of
the accelerator group that
built the 1 GeV Frascati
Electrosynchrotron
in
the
fifties, and is housed in the
same hystorical building.
Today it is a part of “Technical
Unit for the Development of
Applications
of
Radiation
(UTAPRAD)”.
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UTAPRAD
• UTAPRAD is Directed by Dr. Roberta Fantoni, is formed by
95 staff members, and is addressed to the development of
applications of radiations.
• UTAPRAD is aimed to research and technological services,
by means implementation of technologies for the application
of ionizing and not-ionizing radiations, the development of
particle accelerators of optoelectronics and photonics.
• Its role specifically includes technologies for physical
diagnostics in the fields of: environmental and health
protection, cultural heritage preservation, security and
development of accelerators for medical applications.
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Very short introduction to
HADRONTHERAPY AND
PROTONTHERAPY
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Hadron therapy and Protontherapy
• Hadrontherapy = radiotherapy
Bragg’s peak
with protons and ions.
•Protontherapy = radiotherapy with
protons.
Dose
delivery
limited by
the Bragg’s
peak depth
• Advantages:
•
patial selectivity that implies a
conformal therapy.
•
Less irradiation of surrounding
healty tissue
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Intensity Modulated Proton Therapy (IMPT)
IMPT employs techniques similar to those exploted in IMRT
(Intensity Modulated RadioTherapy) to obtain conformal dose
concentrations in the tissue. IMPT allows for more conformality
with less dose concentrations in surrounding tissue.
7 fields with IMRT
2 fields with IMPT
Comparison
between IMRT
and IMPT
Dose difference
between the IMRT
and IMPT
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Description of
THE TOP-IMPLART PROJECT
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The TOP-IMPLART project
In 2008 the TOP-IMPLART (Intensity Modulated Proton
Linear Accelerator for RadioTherapy) was setup in
collaboration with con ISS e IFO, with the aim of building a
protontherapy LINAC to be housed in the largest oncological
hospital in Rome, IFO.
In 2010 it was approved the Funding of the project with a
11 M€ grant from Regione Lazio, Innovation Department.
30MeV Prototype (first milestone)
TOP-IMPLART layout (230MeV, 3 beam lines)
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The TOP-IMPLART project
Aims of TOP-IMPLART Project are
Setting up a proton therapy
facility highly innovative and compact in the Rome
area in collaboration with prestigious academic
institutions with scientific and clinical expertise
Promote the development
of a marketable product and transferring the knowhow to Italian industries, similarly to what done in the
field of IORT, in order to increase the Italian
technological potential and in particular the Lazio one,
in the field of 'High technology applied to the
biomedical sector’
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The TOP-IMPLART project
•
•
•
•
•
•
•
•
•
•
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Modularity:
the accelerator is composed by a
sequence of subsystems optimized
for medical use.
the system can be built in successive
phases matching funding flow and
allowing fast return of investment
from SSN (public health) or private
insurance plans.
Technical characteristics:
3 GHz RF: compactness, well-known
technology.
Pulsed operation: possibility of XYZSCAN for Intensity Modulated
ProtonTherapy (IMPT).
Beam with high optical quality:
smaller magnets.
Italian project:
Italian design and patents
Italian SMEs are involved in the
development of the prototype in
ENEA .
Long term goal of developing an
italian company or consortium of
SMEs to build medical accelerators.
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The TOP-IMPLART project
The structure of TOP-IMPLART LINAC showing modularity in the
accelerating structures and in the RF distribution. All the RF sources are
10MW peak power (10 kW average) TH2157A klystron tubes. This
guarantees more than 30% power margin. Duty cycle will be lower than
5e-4.
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PL7 and TOP IMPLART important dates
•
1999:
–
•
2000:
–
•
Ragione Lazio approved funding the project with a grant of 11M€
2013:
–
•
TOP-IMPLART project presented to Regione Lazio
2010:
–
•
End of site preparation and granting of authorizations (started in 1994)
Injector installation and operation
2008:
–
•
Factory Acceptance Tests
Delivery on May 10th
2005:
–
–
•
Injector order placed on March 7th
2001:
–
–
•
Tender with JPAW Acc Works and Northrop Grumman
Selections for recruiting new personel for the project (physicists, engineers and
technicians). Recruiting completed in Dec 2013. 11 people assigned to the project: 4
physicists, 3 engineers, 2 technicians, 1 administrative assistant, and 1 PhD student
(electromagnetism track)
2014:
–
Installation and commissioning of first 3GHz SCDTL structure
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PL7 and TOP IMPLART important dates
•
2015:
– First quarter: installation and commissioning of the first three SCDTL
accelerating sections to reach 27MeV
– Second quarter: installation and commissioning of the fourth SCDTL to
reach 35MeV
– Final part of the funding (6.5 M€) will be released from Regione Lazio.
Condition for release is reaching an energy of (about) 30MeV
•
2016:
– Energy of clinical interest will be reached
•
2017:
– 150 MeV milestone
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Description of the
ACTUAL LAYOUT OF TOP-IMPLART
LINAC
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Actual Layout
Radiobiology line 3-7 MeV
11.6 MeV
Injector
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The injector
TOP-IMPLART injector is a commercial LINAC manufactured by AccSys-Hitachi
(4.6 m long). It is composed by:
• Duoplasmatron source with current limiter (focusing + perture) to 30 uA
• 3 MeV RFQ operating at 425 MHz
• DTL up to 7 MeV at 425 MHz
Beam spot
Pulsed current:
fuorescent screen
• Pulse width (20-100 μs)
dia =20 mm
Beam size 2 mm
• Pulse rep. freq. 0-200 Hz
Current can be varied in
the
0 – 30 μA varying
Einzel lens voltage (pulsed
operation underway
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PL7 – 003 and LEBT
Panoramic (distorted) picture of the injector and LEBT (Low Energy Beam Transfer)
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Vertical line
Steel holder (=13mm) contains cells (6µm
thickness) on Mylar (60µm thickness) over
their culture medium.
90°
magnet
69 cm
Kapton window (50µm thickness)
Scatterer (gold foil, 2µm
thickness)
Aluminum collimator ( =2 mm)
The vertical extraction line, situated in
the middle of the LEBT is dedicated to invitro radiobiology experiments.
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SCDTL-1 Module
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SCDTL-1 Module
Accelerating
SCDTL-1 tanks number
Length
Pipe radius
(proton beam
hole radius)
Input power
Starting energy
Ending energy
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1.1 m
2 mm
1.3 MW
7 MeV
11.6 MeV
Made by CECOM
(Guidonia, Roma)
PMQ
tank
PMQ dissassembly
Tank interior
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Experimental verification of SCDTL-1
performances
6000
11.6
4000
3000
2000
1000
0
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6
7
8
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energy(MeV)
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Energy measurement obtained
from range measurement in
Aluminum.
Transmission curve vs Al
thickness.
1000
900
800
700
600
500
400
300
200
100
0
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11.1
11.2
11.3
1.2
11.4 11.5 11.6
energy(MeV)
11.7
11.8
11.9
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Accelerated beam
current =15 µA
1
Transmission
5000
43% of the
beam has an
energy
greater then
11 MeV.
Energy peak
is around
11.63 MeV
0.8
0.6
Measurements
0.4
computed transmission curve
for 11.6 MeV
0.2
0
630
660
690
720
750
Al (um)
780
810
840
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New development:
TOP-IMPLART SINGLE ROOM
FACILITY
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Single Output facility
In a Green field situation, the low beam losses
(35% transmission) and the low average
energy of the lost particles allow thinking of a
locally shielded accelerator, with single output
beam, The heavy shielding would only be
necessary for the treatment room
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Our experience with
PL7 - 003
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Features of PL7-003
• Proton source:
– Duoplasmatron Source 30 keV
•
Acceleration
– RFQ 3 MeV
– DTL 4 MeV
• Control Software:
– LINCON 1.1 written by Marianne Hamm on Labview 6.1, running on
Windows 98
– LabView source available
– We have an updated version of the software running on a newer PC.
– We tested the new combination but we never used it because of
many controls are unconsinstent to settings
– Alternative to optical control boards ? (Group3 are obsolete)
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Special requirements for our PL7-003
• Pulse Current:
– Availability of Low and High current for different
applications:
• Radioisotope production : 8 mA per pulse
• Protontherapy linac injector: 100-10-1 μA per pulse
– Retractable (1 mm dia) copper aperture at RFQ input
• Pulsed Einzel Lens current to modulate output
current:
– Hard tube pulser designed by George Engemann(?)
never worked
• Reduced DTL pulse:
– 3GHz LINAC works with a 4μs pulse
– Need for a DTL pulse of up to 7 us
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Modifications applied to our PL7-003
• We ended high current operation of the injector.
– Only low current is available now.
• Beam aperture has been changed and slightly increased to reach
200 uA beam current.
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Modifications applied to our PL7-003
• We have manufactured a new Einzel Lens for
the injector in our laboratory as ACCSYS did
non repair it.
Old Einzel Lens
New Einzel Lens
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Planned or undwerway Modifications to
our PL7-003
• The following modifications have been planned to give better control to injector
current and eventually suppress it for one or more pulse.
• Current control is important for medical applications.
• We have commissioned to a SME company an High Voltage pulsed source for the
Einzel:
– The pulser has been delivered to our facility and is currently under HV test.
• An external enabling arc discharge is in development.
• We are evaluating the possibility of inserting a chopper (10kV, 4cm) in front of the
Einzel lens.
– Hints ?
• (?) Negative pulse on Pierce electrode (?)
• We would like to set and read injector variables from our control system (LabView
2014) to integrate it into the higher level control system.
– How we can do this ?
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PL7-003 operation: Our Way
• We always operate PL7-003 at low current (200
uA) with external trigger using a PRF in the 10 –
50 Hz range
• Cavity fields:
– RFQ Cavity field 4 -4.25 (Standard 4.11)
– DTL Cavity Field 4.7 – 5.35 (standard 5.2 – 5.34)
• Remark: it is impossible, of course, to make
reflected power vanish both in RFQ and DTL
– We asked Accsys several times to adjust coupling
coefficient by loop rotation, without uccess.
– Never mind, we can still operate this way: we can
loose some power.
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Remarks
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We found that the PL7 machine has been well done.
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The old control systems (LINCON 1.1) it is functional and well designed.
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There is no written explanation of procedure,
Potentiometers on the boards have no clear mark of their function
Sometimes at high rep rate DF yellow light prevents operation
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•
How we can improve arc stability at low currents ?
Feedback loops are hard to adjust:
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The drawback is that is not possible to interface it with an higher level control system
We need an open system.
Arc is not properly stable for very accurate and stable operation at low currents
–
•
Electronics systems are well explained in the schematics (This is very important for such kind
of machines).
We experienced some complexity and redundancy in controls and interlocks that sometimes
seems to cause strange faults
We could not trace back to the cause
We need for an electronic maintenance training course
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Thank you for attention!
Coming to the
END
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Merry Christmas and happy 2015
… from TOP-IMPLART teame
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Discussion
Some point for discussion
1.
2.
3.
4.
differences between actual machines and the one we have.
Understanding the AM loop and how to tune it
Tube testing system
Latest developments on the control software: latest release, controller
boards, source availability
5. Ask John Sexton about a possible visit to us
6. Request for offer for a maintenance course for the PL7
7. Are you using FPGA boards on newer machines ?
8. Have you a working Einzel Lens pulsed source ? We have a design from
George Engemann but we do not know if it works and how to operate
it
9. New development in duoplasmatron source
10.Visit to factory
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