thomas ries selected portfolios_20150604

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Project Work Samples - Thomas C. Ries

Contents

Table 1: TRIUMF ARIEL Electron-Linac Engineering Design/Development Project ............................ 2

Table 2: Isac-II Super Conducting Linac Low Beta 4 RF Cavity (SCB) And High Beta 6-8 RF Cavity

(SCC) Cryomodule Engineering .......................................................................................................... 5

Table 3: Custom Designed Pressurized SF6 Vessel For Housing 300 KV Low Current HV Power

Supply With Special Gas Isolation HV Feed-Through For The M9 Beam Line Particle Separator At

TRIUMF ............................................................................................................................................ 10

Table 4: Custom Designed Computer Controlled Positioning And Beam Line Support System For

The Cesium Iodide (CsI) Detector Assembly For The LANSCE NPDGamma, N + P → D + Γ,

Experiment Collaboration ................................................................................................................ 15

Table 5: Custom Designed Computer Automated And Controlled Magnetic Field Mapper For The

Superconducting G0 And The Room Temperature Q-Weak Magnetic Solenoid Spectrometers ..... 21

Table 6: Custom Designed Computerized Patient Positioning Platform For Cancer Treatment With

Pions ................................................................................................................................................ 26

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Table 1: TRIUMF ARIEL Electron-LINAC Engineering Design/Development Project

As Lead Engineer, Chaired Engineering Design Progress Meetings (Posted Above On ARIEL Site), Took Minutes And Made Presentations, For Over A

Year And A Half, For The Development Of The Superconducting Electron LINAC (E-LINAC), For

The Accelerator Cryomodules, The ACM, Including The Injector Cryomodule, The ICM For The VECC

Collaboration Presently Being Built For The Advanced Rare Isotope Laboratory (ARIEL)

Program At TRIUMF.

Progress Update Report for The ARIEL VECC Injector Cryomodule ICM design for the E-LINAC. Shows the adaptation of the JLab Scissor Tuner to the 9-cell 1.3 GHz RF cavity assembly. Shows the adaptation of the

ISAC-2 LINAC Cryomodule cold mass support Strong Back system to the ACM/ICM cavity cold mass Helium tank unit. Shown below are the thermal intercepts, power coupler and gimbaled support, vacuum

tank and ACM Cryomodule Cold Mass Support concept design.

Beam Line Thermal Intercept

Power Coupler And Gimbaled Support For

Perfect Position Guidance During Cool Down

Displacement Of The Electrode End

ACM Vacuum Tank And Alignment Base Structure

ACM Cold Mass Truss Support System With All Ancillary Devices Mentioned Above

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COVER PAGE FOR MY PRESENTATION TO THE DESIGN REVIEW COMMITTEE

E-LINAC CRYOMODULE MECHANICAL DESIGN VS ISAC-II

Vacuum Tank Concept & Engineering

Strongback Design Specs

Stronback and Struts Deflection and Stress FEA

Struts & Cold Mass Cooling Rates With Stresses And Deflections

The Jefferson Lab Scissor Tuner Adapted to the 9-Cell Cavity

Scissor Tuner & Cavity Unit FEA Simulated For Stresses/Deflections

And Validation Of Performance Specifications

5 - D.O.F. Coupler Support Guide Maintains Electrode Position w.r.t. Cavity Axis During Cool Down Deflections Of Cold Mass

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……….

………..

A Visibly Favorable Evaluation Of The ACM/ICM Concept Design By The Review Committee. Received Continued

Funding For 5 Years As A Result.

……………

…………..

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Table 2: ISAC-II Super Conducting LINAC Low Beta 4 RF Cavity (SCB) and High Beta 6-8 RF Cavity (SCC) Cryomodule Engineering

Publications, Design Notes and Graphics Relating to Contributions to the Engineering of the ISAC-II SCB and SCC LINAC Cryomodule Components

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As Built ICAC II SCB and SCC Cryomodule and Controls Installations and FEA Analysis of Cold Mass Structures

SCB 4 Cavity Cold Mass Assy. Hanging From Vacuum Tank Lid

Diagram of High Band Width Tuner Linear Motor and Linkage System

Tuner Plate/Linkage shown Installed in Class III Clean Room

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X-Deflection of 8-Cavity Strut Support Due to Gravity Loading

Stiffness Test of 8 Cavity SCC Strongback and Strut Support System

Vacuum Load (1 atm) Stress/Deflection FEA of SCC 8 Cavity Vacuum Tank

Z-Deflection of 8-Cavity Strut Support Due to Gravity Loading

Weld stresses and End Cap Deflections for the LHe Reservoir

Modal FEA of the Resonant Frequencies of the 8 Cavity SCC Strongback and Strut Support

System

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Assembly Jig For the Prototype SCB Cold Mass in the Class III Clean Assembly Room

SCB 4 Cavity High Bandwidth Tuner Motors Shown Along With All Cryogenic Ancillary

Equipment on Top of the Vacuum Tank Lid in Class 2 Clean Room, Being Tested

Prototype Low Cost SCC Tuner Actuator

Front of 4-Tuner Control Amp Cabinet, Showing Digital Servo Amps, Safety Interlock Relay PCB, Interface PCB, and Motor Power Cable Chokes

Back of 4-Tuner Control Amp Cabinet, the High Voltage Safety Relays, Power Supplies, and

Serial to Ethernet Converter

Interface PCB between the Digital Motion Controler (DMC) Plugged into the PCI Buss of

the RF Controls Computer and the Motor Control Amplifier Cabinet

Tuner Cabinet Front Door Motor Controls/Amplifiers Status Indicator lights

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One Row Of 4 Cavity Tuners And RF Power Amplifiers And Controls Shown..

10 rows of 4 cavity power amplifier and control cabinets show installed and operational.

ISAC-2 SC LINAC vault showing all of the CRM’s and beam line ancillary devices.

2 Of The 4 Tuner Motors Shown Atop The 4 Cavity Low Beta SCB Cryomodule Shown Installed And

Operational. 5 CRM’s altogether.

The top of the 3 high beta SCC Cryomodules are shown installed and operational.

3 Of The 6 Tuner Motors Shown Atop The 6 Cavity SCC Cryomodule Shown Installed And

Operational. 3 CRM’s of this type.

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Table 3: Custom Designed Pressurized SF6 Vessel for Housing 300 KV Low Current HV Power Supply with Special Gas Isolation HV Feed-through For the M9 Beam Line Particle Separator at TRIUMF

Figure 1: M9 Separator 300KV power supply housing vessel.

Figure 2: HV PS tank located on its leg stand.

Figure 3: The High Voltage SF6 pressure barrier feed through custom design.

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Product Description Custom Designed Pressurized SF6 Vessel For Housing 300 KV Low Current HV Power Supply With Special

Gas Isolation HV Feed-through For the M9 Beam Line Particle Separator at TRIUMF

Capabilities Applied/Processes

Lead Engineering and Project Management.

Design Concept Development:

Conception of the housing systems that meets unique SF6 gas containment pressures and all surface

geometries are configured such that the Factors of Safety are well outside the Breakdown Voltage

values.

Designs sketches and design approvals.

Structural design of the PS and the gas containment housing and support structures.

Control System Development:

LV and HV circuit wiring, cabling, and safety code approved HV stack voltage/current wiring and

packaging.

FEA Stress and Deflection Analysis of All Detector support cassettes to meet maximum allowable

Load/Deflection Requirements.

Supervision of shop drawings, parts fabrication, assembly, setup and commissioning.

Documentation provided in hardcopy and digital form.

Long term product/software testing, development and support.

Features

This “non-ASME pressure vessel” 15psig SF6 tank housing is actually designed for a maximum allowable

working pressure, MAWP of 85psig, but is used at a much lower pressure to avoid having to obtain BCSA

pressure vessel and pressure fitting approval.

This HV PS can be used with SF6 under pressure ≤ 85psig, but BCSA approval of the design is required.

The high voltage connector can be easily replaced without having to depressurize the PS tank housing, in

case the current limiting safety resistor is burnt out, and the feed through must be disconnected for its

replacement.

Each PS tank attached to its stand leg is seismically designed to be earthquake safe to a seismic ground

acceleration of 0.6g in any direction.

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Benefits

At low SF6 pressures, PV approval not required.

Can be used at higher SF6 pressures for higher output voltages, but PV approval required.

The environmentally damaging gas SF6 is contained at all times.

Earthquake safe.

Industry For Use Nuclear Particle Physics Research. Experimental Beam lines.

For powering electrostatic mass separators.

Any other industry where safe low current and High Voltage sources are required.

Delivery Location 4 units Installed into the rebuilt M9 Beam Line for the µSr Group in the Meson Hall at TRIUMF.

Standards Met Standard Shop Fabrication Drawings and Costumer Specifications.

BCSA and ASME Pressure Vessel Codes.

Documentation

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Table 4: Custom Designed Computer Controlled Positioning and Beam Line Support System for the Cesium Iodide (CsI) Detector Assembly for the LANSCE NPDGamma, n + p → d + γ, Experiment Collaboration

Custom designed, built, and,

commissioned at LANL by TCR for the

U. of Manitoba NPDGamma

experiment collaboration group at

TRIUMF, and was used to support

along with other beam line

experiment specific devices (i.e. spin

flipper, monitor, para-hydrogen target

vessel, etc.), the CSI detector assembly

and facilitate remote control of its’

position and orientation with respect

to the incoming cold polarized

neutron beam. This portable and

remotely actuated carriage system is

able to move the CSI detectors

horizontally and vertically, as well as

adjust its’ roll and pitch angles as

required, by differentially moving the

3 vertical lift points. The movement is

controlled by a PC running TCR

designed and developed Labview

Control GUI programs.

This figure shows the arrangement of the detector array around the liquid hydrogen target. The array comprises 48, 150x150x150 mm3 cubes of

CsI. To determine the effective centre of each CsI cube, the whole array is moved and the cube positions are calculated from the variations in yield

with position. The motion is accomplished by a computer controlled precision motion system developed and built for the TRIUMF/Manitoba

group.

CsI (Cesium Iodide) crystal detector assembly for the NPDGamma experiment as installed into the “cave” on flight Flight Path 12 (FP12) at LANSCE (Los Alamos Neutron Science Centre).

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Product Description

Capable of 5 DOF precision motion, this computer controlled carriage support system positions

from a remote location 48 CsI cubes arranged around a liquid hydrogen target cryostat for the

LANSCE NPDGamma, n + p → d + γ, Experiment Collaboration at LANL (Los Alamos National

Laboratory) while supporting all ancillary devices related to this experiment.


Lead Engineering and Project Management.

Design Concept Development:

o Conception Of Carriage System That Meets Unique Support And Positioning Requirements

o Designs Sketches and Design Reviews Approvals.

o Machine Design of 5-axis positioning stages and support structures.

Control System Development:

o Stand Alone DMC (Digital Motion Controller) configuration software written.

o Labview GUI Panel Control Codes for Jack screw lift synchronization, detector positioning and

orientation control and monitoring, servo amp and DMC startup initialization, limit switch

and failsafe monitoring, servo motor condition monitoring and more.

o Specifying Electromechanical hardware and Purchasing of Digital Motion controllers,

servomotors, absolute encoders, servo amplifiers, cables and wiring, ball screws, linear

bearings, jack screws, etc.

o LV and HV Circuit wiring, cabling, and LANL Electrical Engineering safety Code Approved

controller cabinet packaging.

o Emergency drive system freeze, limit switch safety interlocks design in both hardware and

software. Hard end stops on all drives with safe torque limiting.

FEA Stress and Deflection Analysis of All Detector support cassettes to meet maximum

allowable Load/Deflection Requirements.

Supervision of Shop Drawings, Parts Fabrication, Assembly, Setup and Commissioning.

Documentation Provided in Hardcopy and Digital form.

Long Term Product/Software Testing, Development and Support.

Long term support for users.

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Features

Vertical actuation of support points via 3 Joyce 2 ton lead-screw jacks.

Stand Alone DMC1860-MX "Galil" Digital Motion Controller for supervisory control.

USB or Ethernet communication between PC GUI Code and the DMC controller unit.

Kollmorgen brushless servo gear motors with 1000 line/turn absolute optical encoders for each

axis.

End of travel and home (calibration) limits; end of travel bumpers; adjustable slip torque limits.

Auto start up self calibration codes written.

Benefits

Portability; Ease to transport entire fully loaded detector support assembly via overhead crane

or by fork lift.

Stiff servo actuation systems for producing highly accurate positioning capability.

Overall Measurement Envelope All drives have maximum reach of +/- 15 mm

Maximum Load Capacity & Deflection

Requirements Met 2400 lbs load @ 0.001” average deflection at detector level.

Tightest Tolerances

Position Repeatability: +/- 50 microns

Position Resolution: +/- 25 microns

Position Absolute: +/- 50 microns


Any other industry where highly accurate positioning is required of very heavy payloads.

Delivery Location Installed into the “cave” on flight Path 12 (FP12) at LANSCE (Los Alamos Neutron Science

Centre).


Product Name NPDGamma Experiment CsI Detector Positioner, Cryogenic Target, and Beam Line Devices

Support.

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Detector Power Amp Control Crate Located Outside Next to Cave FP(12). PC on top left.

Completed Installation Of The NPDGamma CSI Detector Assembly In The FP12 Cave. It

is inside the Black Lead Box Radiation Shield

Brushless Servo Motor/Jack Screw/Hard

End Stop/Soft Limit Switches Drive Cluster.

Servo Amplifiers, Power Supplies, and

Stand Alone DMC Unit (below) is Connected (via white cable) to the 4 Blue Servo Amps.

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Position/Orientation Control Panel GUI and DAQ Written in LabView VPL

Snap Shots of the Visual Codes, Behind the GUI, Running the CsI Detector Positioning and Data Acquisition System

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Power Amp Cabinet Containing Servo Motor Amps, PC, Stand Alone Digital Motion Controller, Power Supplies, …etc.

Cut Away Showing the Array of Individual CsI Detector Cubes Along With the Cryogenic

Target Inserted at the Center.

The 4 Servo Actuator Drive Stages providing 5 DOF Motion, Shown From Bellow

FEA showing stress and deflections of the insulator polyimide crystal CsI detector crystal support plates (2x4 detector matrix support). 1x4 matrix plates, not shown here, were also analyzed.

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Table 5: Custom Designed Computer Automated and Controlled Magnetic Field Mapper for the Superconducting G0 and the Room Temperature Q-Weak Magnetic Solenoid Spectrometers

The Magnetic field mapper in front of the G0 Superconducting Magnet

Solenoid shown in scan ready position

Custom designed and built by TCR for the U. of Manitoba Nuclear

Particle Physics Group at TRIUMF, and was used for the G0 and Q-weak

experiments at JLab, this portable and computerized magnetic field

mapper is able to move along the x, y and z axes (left/right, up/down,

forward/back). The movement is controlled by a PC running Labview

Control Panel GUIs. The G0 Magnetic Field Mapper is used to scan

specific fringe field regions of the G0 Superconducting Magnetic

Spectrometer to locate a series of pre-selected magnetic reference points,

which in turn, allow for the determination of the positions and orientations

of the individual spectrometer coils. As part of a series of required

measurements related to quality control in the spectrometer fabrication

and commissioning process, the Magnetic Field Mapper will be used in

the “Final Acceptance Magnetic Verification Test of both the

superconducting and Room Temperature Magnet Systems”.

Product Description

This Custom Designed Transportable Computer Controlled Magnetic Field Mapper Is Designed For The Magnetic Field Verification Of The G0 Superconducting And Q-Weak Room Temperature Magnetic Solenoid Spectrometers Destined For Verification Of The Two Basic Types Mentioned Spectrometer Solenoids At Jefferson Lab. Is Also Being Used For Mapping Solenoids, Quadrupoles, Focusing Magnets, Benders, Etc., Where Ever Needed.


Project engineering management

Design Concept Development: o Conception Of Carriage System That Meets Unique Support And Positioning Requirements o Designs Sketches And Design Reviews Approvals. o Machine Design Of 3 Axis Gantry Mapper Carriage System. o Design and Development

Development Of Labview GUI Control Panel Software:

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o Control Codes for Manual and Automated Magnetic Field Mapping and Field/Position Data Acquisition.

o Codes For Calibrating Mapper Using Laser Tracker With Corner Cube Reflector Attached To Probe Head Housing.

o Safety codes for contact preventions between the probe head and magnet.

Electrical hardware design/development: o Servo gear motor/encoder cabling to digital servo amplifiers. o Cable track design and installation. o Emergency drive system freeze, limit switch safety interlocks design in both hardware and

software.

FEA Stress/Deflection/Buckling/Modal Analysis of Entire Structure to Meet Safety and Maximum Allowable Deflection to meet Specified Load/Deflection Requirements.

Supervision of Shop Drawings, Parts Fabrication, Assembly and Setup/Commissioning.

Documentation Provided In Hardcopy and Digital form.

Long Term Product/Software Testing, Development and Support.

Training Provided For Operations And Maintenance.

Features

Utilizes Bosch Linear Bearings With Belt Drives For Anti-Backlash Highly Reproducible Positioning Of Field Probe Head.

DMC1860-MX PCI bus "Galil" Digital Motion Controller for supervisory control.

Kollmorgen brushless servo gear motors with 1000 line/turn optical encoders for each axis.

End of travel and home (calibration) limits; end of travel bumpers; adjustable slip torque limits.

Auto start up calibration.

Benefits

Portability; breaks down into 3 sections; packs into single compact unit which fits into a standard panel truck.

Stiff servo actuation systems for producing highly accurate positioning capability (Bosch Spec: +/-50 microns).

Universal mapping device for measuring the magnetic fields from both large and small solenoids and magnets.

Large Dynamic Range.

Short Settling Time at Maximum Extension (~2 seconds with S-curve velocity profiling).

Overall Measurement Envelope Width (X-dir. Base Carriage Length): 4.51m (177")

Height (Y-dir Vertically): 4.4m (173")

Depth (Z-dir. Beam Axis): 1.94m (76")

Maximum Load Capacity & Deflection

Requirements Met 0.1mm/lbf deflection rate, total, at probe head level.

Maximum load capacity of probe head support = 15lbs.

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Tightest Tolerances Position Repeatability @ Probe Head Level: +/- 100 microns

Position Resolution @ Probe Head Level: +/- 50 microns

Position Absolute @ Probe Head Level: +/- 1mm (+/- 200 microns If Calibrated with Laser Tracker)


Any industry where accurate 3D magnetic field mapping is required.

Delivery Location NPL at UIUC (Nuclear Physics Lab at University of Illinois Champain/Urbana)

MIT BATES Lab (Nuclear Physics Lab at MIT)

Jefferson Lab (Nuclear Physics Lab in Virginia)


Product Name G0 (and QWeak) Solenoid Spectrometer Magnetic Field Mapper.

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The Gantry being Calibrated In front of the Q-weak experiment mass spectrometer @ the MIT Bates Nuclear Physics Lab.

G0 Gantry Motion Control and DAQ Panel GUI. Contains integrated position calibration, field scanning, motor control, safety interlock

and Data Acquisition software.

Showing the Vertical Carriage @ UICU Nuclear Physics Lab.

Showing the XYX Motion Carriages With the Field Sensor on the Boom Head On @ UICU Nuclear Physics Lab.

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Using a Mock Up Solenoid Cover Plate to Test the NO GO ZONE Safety Interlock Software @ UICU Nuclear Physics Lab.

Setting up the 6-Axis Magnetic Field Probe at the End of the Boom @ UICU Nuclear Physics Lab.

Corner qube reflector marking the position of the 6 D.O.F. magnetic field probe calibrating the Gantry position sensors @ JLab.

The Leica laser tracker team recording the absolute positions of the moving corner cube during calibration of the Gantry @ JLab.

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Table 6: Custom Designed Computerized Patient Positioning Platform for Cancer Treatment with Pions

Custom designed and built, by TCR for

TRIUMF, this computerized treatment

couch is able to move along the x, y and z

axes (left/right, up/down, forward/back).

The movement is controlled by a

computer which can position it precisely

in front of the pion beam. The patient lies

on the couch and the computer controls

the couch's movement so that the tightly

focused beam of pions will sequentially

and very precisel irradiate throughout the

tumor volume.

Product Description

This Custom Designed Cancer Treatment Couch Was Used By The B.C. Cancer Agency

(for a total of 10 years, the life cycle of the experiment) For Researching The Use Of Pion

Beams For The Treatment Of Brain And Pelvic Cancerous Tumors.


Project Engineering and Management.

MACHINE DESIGN of 5 Axis (Total) Couch Support Gantry Carriage System Design.

Conception Of Carriage System That Meets Unique Support And Positioning

Requirements.

Drawings Of Concept Designs And Obtain Approval At Design Reviews.

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Stress / Deflection Analysis Of Entire Structure To Meet Safety And Maximum Allowable

Deflection Under Specified Load Requirements.

Supervision Of Parts Fabrication And Installation.

Start-Up.

Documentation Provided In Hardcopy.

Training Provided For Operations And Maintenance.

Long Term Product Testing Support.

The Electrical Design And Controls Software Was Done By The Electronics Division.

Features

Utilizes Ball Screw Drives And Linear Bearings For Anti-Backlash Highly Reproducible

Positioning Of Table.

3 Axis Are Computer Controlled, 2 Axis Are Manually Adjustable At Table Level.

Carriage System Supported Only From Ceiling. Leaves False Floor Free For Low Weight

Payload (I.E. Patients, Nurses, Doctors And For Cable/Piping Maintenance Below) Use.

Disconnectable Room Length Ceiling Track Drive For Moving Couch Out Of Way Of

Patient Set Up And Beam Line Equipment.

Fail Safe Breaks And Absolute Encoders Were Used To Meet Safety Requirements.

Local Velocity Control Pendant For Prepositioning Couch Before Computer Takes Over.

Benefits This Device Allows For Highly Precise And Repeatable Treatment Of Cancerous Tumors

For Research.

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Maximum Possible Travel Along THK Linear Bearings

Width (X-dir. Table Length): 180"

Height (Y-dir Vertically): 60"

Depth (Z-dir. Beam Axis): 60"

Overall Treatment Envelope

Width (X-dir. Table Length): 48"

Height (Y-dir Vertically): 40"

Depth (Z-dir. Beam Axis): 48"

Maximum Load Capacity & Deflection Requirements Met

1000 lbs./1mm deflection at couch table level. Used for beam calibration with water

tank.

Tightest Tolerances

Position Repeatability @ Couch Table Level: +/-0.005"

Position Resolution @ Couch Table Level: +/-0.002"

Industry For Use Cancer Research Using Nuclear Particle Accelerators.

Delivery Location Batho-Biomedical Research Center At TRIUMF (Now Occupied By The Musr Group)

Standards Met Standard Shop Fabrication Drawings, Cancer Agency specifications and Site Safety

Requirements.

Product Name Custom Designed Computerized Cancer Treatment Couch

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TRIUMF - Cancer Therapy with Pions

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TRIUMF: Cancer Therapy with Pions

Each year more that 500 Canadians develop glioblastoma brain tumors, and 35,000 Canadians receive radiation for all types of

cancer. In situations where the cancer has not spread beyond the original tumor site, localized radiation treatment may be more effective that other treatments in achieving tumor control and possible cure, if higher radiation doses can be delivered without excessive damage to normal tissues. This is the challenge for pion therapy.

Pion therapy

Pion radiotherapy is a novel form of cancer treatment that has been extensively investigated for tumors of the brain and pelvic area. A drawback of conventional radiation therapy (with photons) is the unwanted radiation which it delivers to the healthy tissue surrounding the tumor as it penetrates to where the cancer cells are located. In contrast, pion therapy concentrates the cell-killing power of the radiation more selectively in the tumor, while reducing the effects on nearby normal tissue.

Welcome Page Research Areas Pion Therapy

http://legacyweb.triumf.ca/welcome/index.html

http://legacyweb.triumf.ca/welcome/research.html

http://legacyweb.triumf.ca/welcome/pion_thrpy.html

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What is a pion?

Pions belong to a group of short-lived subatomic particles called mesons. They are the lightest of the mesons, having about one seventh the mass of protons or neutrons. Some are electrically neutral, while others carry a single positive or negative charge. (Only the last kind is used in pion therapy.) Pions are not normally found in the free state in nature: they exist inside the nuclei of atoms, where they constitute the "glue" that holds the neutrons and protons together. But in some types of reactions, e.g. when a nucleus is struck by a proton having a certain energy, pions are ejected from the nucleus. TRIUMF uses this method to generate vast numbers of pions in its meson hall. Beams of charged pions can be guided, bent or focused by magnetic fields, just as light beams are controlled by prisms or lenses.

Producing pions

The pions employed for this unique form of cancer therapy are produced using the TRIUMF cyclotron. This cyclotron, the world's largest, accelerates hydrogen ions (which are composed of one proton and two electrons each) to 75% of the speed of light. The ions are then passed through a thin piece of metal foil which strips off the electrons, leaving a beam of protons. These protons travel away from the cyclotron at 225,000 kilometres per second inside a metal pipe. Next the protons collide with a target of carbon or beryllium, and pions (or "pi-mesons") are knocked out of the target's atoms. Although they exist for only 26 billionths of a second, the pions travel extremely fast. There is enough time for them to be channelled up a second pipe (called the biomedical beam line) to reach the cancer treatment area.

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which allows them to penetrate down into the tumor - but no further. By the time a pion reaches the tumor, it has slowed down so much that it can be drawn into the nucleus of an atom within a cancer cell. The capture of this foreign object makes the nucleus unstable, and it breaks up violently into smaller fragments which fly apart, producing what is called a "pion star". Since the fragments will damage surrounding cells within a short distance, more than just the unstable nucleus is destroyed.

The pion's action can be likened to a depth charge. It sinks through matter (healthy tissue) until, at the end of its "life", it comes in contact with the target (cancer cells) and produces a tiny "atomic explosion" within the cancer. In this way, pions can be used to destroy cancer cells without causing much damage to healthy tissue surrounding the tumor. In addition experiments have shown that the pion star radiation is, dose-for-dose, more effective against certain slow growing and hypoxic (starved of oxygen) cancer cells than conventional radiation. The effective

cancer-destroying power of pion radiation, therefore, is higher than the same dose of photon radiation.

Focusing the pion beam

There is an exact point in space where pions will have slowed down enough to be

absorbed by a nucleus within a cancer cell. The location of this point must be not only known, but precisely controllable. A system was designed and built for collecting pions and concentrating them into a beam. It acts something like a telescope. As a telescope uses lenses to gather light from a large area and focus it into a single spot, the beam transport system uses giant electromagnets to select pions in a specific range of speeds as they exit in all directions from the pion-producing target, and to focus them into a narrow, circular beam. This complex focusing system consists of nine large electromagnets, weighing up to 5000 pounds each, and surrounding a 25-foot- long beam line pipe that extends from the pion production target to the

treatment room in the biomedical facility. The magnets are remotely controlled and monitored by a computer to ensure that all pions reach the same irradiation focus. A high vacuum is maintained in the beam pipe to ensure that the pions do not scatter out of the beam line.

At the point where the pions exit the beam line pipe, a special device is used to adjust the pions' depth of penetration into the tumor. It consists of a series of plastic slabs of different thicknesses, arranged in a circle. The pions are slowed down in proportion to the total thickness of the slabs inserted in their path at a given moment.

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A computerized treatment couch

TRIUMF designed and built the computerized treatment couch which is

able to move along the x, y and z axes (left/right, up/down, forward/back). The movement is controlled by a computer which can position it precisely in front of the pion beam. The patient lies on the couch and the computer controls the couch's movement so that the tightly focused beam of pions will sequentially irradiate throughout the tumor.

In order to keep the patient in the same spot on the couch, a mold is made of the affected area - hip or head. From this, a close-fitting, rigid plastic "mask" is formed. During treatment the mask surrounds

the corresponding part of the patient and is fastened to the couch, firmly holding the patient stationary. The cancerous tumor is now at a known point above the couch, which can then be moved across the pion beam so that the central part of the tumor will receive radiation. The computer can easily direct the pion beam to within half a millimetre of any spot within the body. Prior to the treatment of a brain tumor, CT scans - special X-ray images of the head - are obtained, to assist in planning the treatment. The CT scan images define the exact size, shape and location of the tumor. This information is used to program the computer that operates the treatment couch. (Similar procedures are used to plan the pion treatment of pelvic cancer.) Data from the CT scans may also be used in producing the plastic slabs that are placed between the pion beam and patient, to control the penetration of the pion beam.

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feel a pion beam. Like all forms of radiation therapy there are side effects on the surrounding tissues that limit the dose of radiation that can be administered.

Pion therapy is not currently being used for patient treatments, pending the final results of randomized studies performed in the early 1990's.

More information on radiation therapy and cancer treatments can be obtained from the British Columbia Cancer Agency, 600 West 10th Ave, Vancouver. (604) 877 6000. Toll free (BC only ) 1-800 663 3333.

The National Cancer Institute (US) has an excellent web site with detailed cancer information for both patients and health care providers.

Welcome Page Research Areas Pion Therapy

This page maintained by the Scientific Services Group.

Last changes: Jan 02, 1997.

http://www.bccancer.bc.ca/

http://icicc.nci.nih.gov/

http://legacyweb.triumf.ca/welcome/index.html

http://legacyweb.triumf.ca/welcome/research.html

http://legacyweb.triumf.ca/welcome/past-tech.html

mailto:[email protected]

thomas ries selected portfolios_20150604

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