Thomas Stewart

D-Pace, Inc.

D-Pace’s 13.56 MHz Radio Frequency (RF) multi cusp negative ion source uses an Aluminium Nitride (AlN) dielectric window for coupling RF power from an external antenna to the plasma chamber. Ion source operation was limited to low RF power (< 3500 W) due to failures (cracks) occurring on the window during experiments. Such events can cause damages...

At the King Abdulaziz City for Science and Technology KACST, a beam line injector is being constructed to provide the multi-purpose low-energy, ELectrostAtic Storage Ring (ELASR), with the required high-quality ion beams. The injector is being equipped with a 90 degree high resolution mass analyzing selector magnet system and a new ECR ion source....

The Siemens Eclipse (RDS111) cyclotron utilizes an internal Penning Ion Gauge (PIG) ion source to provide the negative hydrogen ions for this 11 MeV PET cyclotron. Siemens worked with D-Pace Inc. to optimize the ion source current and transmission through the cyclotron to the radioisotope targets. The goal was to increase the target current from 12...

Acetylene and carbon dioxide gases are used in a filament-powered volume-cusp ion source to produce negative carbon ions for the purpose of carbon implantation for gettering applications. The beam was extracted to an energy of 25 keV and the composition was analyzed with a spectrometer system consisting of a 90° dipole magnet and a pair of slits. I...

Recent progress has been made at the newly commissioned Ion Source Test Facility (ISTF) [1]. Phase II, the final phase of the project, was completed in March 2016. First measurements were performed with D-Pace's TRI-UMF licensed H-ion source [2]. The source was first characterized with Hand an extraction study of the H-ions was performed. A study o...

CW 13.56 MHz radio frequency-driven H− ion source is under development at the University of Jyväskylä for replacing an existing filament-driven ion source at the MCC30/15 cyclotron. Previously, production of 1 mA H− beam, which is the target intensity of the ion source, has been reported at 3 kW of RF power. The original ion source front plate with...

Progress is being made in the development of an Ion Source Test Facility (ISTF) by D-Pace Inc. in collaboration with Buckley Systems Ltd. in Auckland, NZ. The first phase of the ISTF is to be commissioned in October 2015 with the second phase being commissioned in March 2016. The facility will primarily be used for the development and the commercia...

This paper describes the proto-type magnet measurement results for a compact (212 mm, effective length) yet large gap (97 mm) ambient air-cooled laminated AC scan magnet. A large aperture is essential for machine safety in radioisotope production, and Boron Neutron Capture Therapy (BNCT) applications with steady-state beam power up to 50 kW *. Rose...

A CW 13.56 MHz radiofrequency-driven ion source RADIS for production of H− and D− beams is under development for replacing the filament-driven ion source of the MCC30/15 cyclotron. The RF ion source has a 16-pole multicusp plasma chamber, an electromagnet-based magnetic filter and an external planar spiral RF antenna behind an AlN window. The extr...

The ISOTRACE Super-Conducting Cyclotron is PMB-Alcen’s re-developed and modernized version of Oxford Instrument’s OSCAR super-conducting cyclotron [1]. Its extracted 80+ micro-amperes of 12 MeV protons are used for the production of PET radioisotopes. Following the philosophy of Dickie, Stevenson, Szlavik [2] for minimizing dose to personnel, and...

D-Pace has developed a compact cost-effective gamma detector system based on technology licensed from TRIUMF [1]. These photodiode detectors are convenient for detecting the presence of positron emitting radioisotopes, particularly for the case of transport of radioisotopes from a PET cyclotron to hotlab, or from one location to another in an autom...

The THC14 PET Cyclotron produced by THALES specifies two compact cost-effective beamlines for high current PET radioisotope production. The design and development of the beamline system was reported previously in NIM B 261 (2007) pp 809-812. This paper describes the successful testing of this compact beamline at the first installation. A series of...

Many of today's PET cyclotrons are delivered from the factory for fully automated operation in a hospital based clinical program. Simplicity and ease of operation by non-specialists is desired, and this is achieved in part through relatively low current targets attached to the PET cyclotron's main vacuum tank. However, commercial scale production o...

As an ion source developer, D-Pace frequently faces the issue of needing access to a research facility to be able to test equipment or to develop our existing technology further. The closest facility to perform such tasks is hundreds of kilometers away, at TRIUMF, and it is not always feasible to make use of it on a timely basis. With a growing dem...

Most commercial PET Cyclotrons have targets mounted on or near the main cyclotron vacuum chamber. There is often little or no system capability for centering or focusing the extracted beam on target to achieve maximum production. This paper describes the ion-optics, design and development of a compact cost-effective beamline comprised of low activa...

A very short (150 mm long) beamline known as the "Short Port" beamline has been developed. It enables users to mount custom high performance targets on their PETtrace™ Cyclotrons. The "Short Port" beamline comes complete with a gate valve, 4-jaw and water- cooled graphite collimator with beam current readbacks, a thermocouple port, and, in the base...

The TRIUMF H− volume-cusp ion source technology licensed by Dehnel Consulting Ltd ranges in output current from 1 to 15 mA with beam energies in the 22–30 keV range. For those Cyclone 30 cyclotrons installed with an early 1980’s style Lawrence Berkeley Lab (LBL) volume-cusp ion source, an upgrade to a 5 mA TRIUMF H− volume-cusp ion source would pay...

In recent years SPECT radioisotope producers have generally built their businesses around 30 MeV cyclotrons. An important aspect of these production facilities is the beamline system which must have a high transmission rate, low residual radiation, and low maintenance requirements. This paper describes developments in these areas.

SPECT radioisotope producers generally utilize commercial cyclotrons which output proton beams in the 20 - 50 MeV range. To separate the target radiation environment from that of the cyclotron, beamlines are used to transport the extracted beams to one or more shielded target rooms. Industrial beamline systems pose an interesting engineering challe...

High current Hcyclotrons (>1000 μA) are being developed and implemented for radioisotope production, radioactive therapeutic implants and other applications. The beam dynamics and general physics design of these cyclotron systems must be well done. However, to not compromise an elegant and effective physics design, engineering practicalities must b...