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 2 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

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)”. An introduction on Accelerator Development in ENEA 3

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. 4

HADRONTHERAPY AND PROTONTHERAPY Very short introduction to 5

Hadron therapy and Protontherapy Hadrontherapy = radiotherapy with protons and ions. Protontherapy = radiotherapy with protons. Advantages: patial selectivity that implies a conformal therapy. Less irradiation of surrounding healty tissue Bragg’s peak Dose delivery limited by the Bragg’s peak depth 6

Dose difference between the IMRT and IMPT 7 fields with IMRT2 fields with IMPT Comparison between IMRT and 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. Intensity Modulated Proton Therapy (IMPT) 7

THE TOP-IMPLART PROJECT Description of 8

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. 9 30MeV Prototype (first milestone)TOP-IMPLART layout (230MeV, 3 beam lines)

10 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 know- how 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’ The TOP-IMPLART project

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 XYZ- SCAN 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. The TOP-IMPLART project 11

12 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. The TOP-IMPLART project 12

PL7 and TOP IMPLART important dates 1999: – Tender with JPAW Acc Works and Northrop Grumman 2000: – Injector order placed on March 7 th 2001: – Factory Acceptance Tests – Delivery on May 10 th 2005: – End of site preparation and granting of authorizations (started in 1994) – Injector installation and operation 2008: – TOP-IMPLART project presented to Regione Lazio 2010: – Ragione Lazio approved funding the project with a grant of 11M€ 2013: – Selections for recruiting new personel for the project (physicists, engineers and technicians). Recruiting completed in Dec 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 13

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 14

ACTUAL LAYOUT OF TOP-IMPLART LINAC Description of the 15

Actual Layout Radiobiology line 3-7 MeV 11.6 MeV Injector 16

Beam spot fuorescent screen dia =20 mm Beam size 2 mm 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 Pulsed current: Pulse width ( μs) Pulse rep. freq Hz The injector Current can be varied in the 0 – 30 μA varying Einzel lens voltage (pulsed operation underway 17

PL7 – 003 and LEBT 18 Panoramic (distorted) picture of the injector and LEBT (Low Energy Beam Transfer)

The vertical extraction line, situated in the middle of the LEBT is dedicated to in- vitro radiobiology experiments. Steel holder (=13mm) contains cells (6µm thickness) on Mylar (60µm thickness) over their culture medium. Scatterer (gold foil, 2µm thickness) Aluminum collimator ( =2 mm) Kapton window (50µm thickness) 69 cm 90° magnet Vertical line 19

SCDTL-1 Module 20

Made by CECOM (Guidonia, Roma) SCDTL-1 Module SCDTL-1 Accelerating tanks number 9 Length1.1 m Pipe radius (proton beam hole radius) 2 mm Input power1.3 MW Starting energy7 MeV Ending energy11.6 MeV tank PMQ dissassembly PMQ Tank interior 21

43% of the beam has an energy greater then 11 MeV. Energy peak is around MeV Accelerated beam current =15 µA 22 Experimental verification of SCDTL-1 performances Energy measurement obtained from range measurement in Aluminum. Transmission curve vs Al thickness. 11.6

TOP-IMPLART SINGLE ROOM FACILITY New development: 23

Single Output facility 24 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

PL Our experience with 25

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) Features of PL

Pulse Current: – Availability of Low and High current for different applications: Radioisotope production : 8 mA per pulse Protontherapy linac injector: 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 Special requirements for our PL

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. Modifications applied to our PL

We have manufactured a new Einzel Lens for the injector in our laboratory as ACCSYS did non repair it. Modifications applied to our PL7-003 Old Einzel LensNew Einzel Lens 29

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 ? Planned or undwerway Modifications to our PL

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 (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. PL7-003 operation: Our Way 31

We found that the PL7 machine has been well done. – 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 The old control systems (LINCON 1.1) it is functional and well designed. – 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 – How we can improve arc stability at low currents ? Feedback loops are hard to adjust: – 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 – We could not trace back to the cause We need for an electronic maintenance training course Remarks 32

END Coming to the 33 Thank you for attention!

34 Merry Christmas and happy 2015 … from TOP-IMPLART teame

35 Discussion Some point for discussion 1.differences between actual machines and the one we have. 2.Understanding the AM loop and how to tune it 3.Tube testing system 4.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