Welcome to Carroll & Ramsey Associates' Home Page
TABLE OF CONTENTS
Carroll & Ramsey Associates' Products and
Services
Introduction--Company Profile
Carroll & Ramsey Associates (CRA) provides service and technical support to the community of accelerator builders and users, including leading cyclotron manufacturers, U.S. Department of Energy National Laboratories, University Research and Clinical PET / Nuclear Medicine Imaging Centers, and Commercial Isotope producers.
The principals--Fred Ramsey and Lewis Carroll--are veteran contributors to the accelerator and PET fields. (See List of Publications.) Our experience spans more than 30 years, first as members of the technical staff of The Cyclotron Corporation (TCC), then as founding members of CTI Cyclotron Systems, and now as partners in an independent small company.
Lewis Carroll has worked in the accelerator field since 1969. He also led the development of innovative Positron Emission Tomography Systems, including the first commercially-produced multi-slice BGO Neuro-Tomograph.
Professional craft skills and specialties include:
Fred Ramsey has worked in the accelerator field since 1962. Professional craft skills and specialties include:
Accelerator System Service and Technical Support
Carroll and Ramsey played a major role in the design, development, manufacture, installation, and servicing of most of the biomedical and radiopharmaceutical isotope-producing cyclotrons currently in use world-wide.
We have supervised the overhaul and reconditioning of cyclotron systems (CS-15, CS-22, CS-30, CP-42, 45, etc.) built by The Cyclotron Corporation (TCC), some of which have been in service since 1966. We continue to provide technical support, on- site maintenance, and repair services for these customers, either through service contract or on an as-needed basis.
We also provide technical support and on-site maintenance and repair services to the community of CTI / RDS-112 and -111 users, as well as GE / Scanditronix and IBA sites.
After-Market or hard-to-find Parts and Supplies
The service-life of a PET / biomedical isotope cyclotron, particularly in a clinical or research-medicine environment, is measured in decades--often exceeding the career tenure of an institution's dedicated technical-support professionals.
Components do wear out and fail after long service. Vendors, Original Equipment Manufacturers, and Suppliers come and go, but we are here to help you find exact replacements (new or reconditioned) or updated functional equivalents for maintenance, repair, and overhaul of your system.
We can supply everything from major components such as Dees and Main Magnet and Harmonic coils, to Power Supplies and Control System parts and components, to consumables such as ion source cathodes, extractor foils, septa, etc. (return to beginning)
Cyclotrons have a very long life, but any piece of equipment will eventually have to be retired from service. From time to time, we have the opportunity to help find new homes for used cyclotrons which, with relatively modest overhaul and refurbishment, can have many more years of productive service, and thus represent a very valuable asset.
The reasons for retiring a cyclotron vary, but it is most often due to an institution's changing priorities or changing needs, rather than due to any fundamental age-related deficiency in the system itself.
Terms and conditions for acquiring a machine from a prior owner obviously vary; sale-price is at the discretion of the owner, but we have seen many situations where the owner is willing to part with a used cyclotron for a token fee in order to avoid the cost and administrative burden associated with disposal as waste or scrap. It is often the case that a used cyclotron, including service documentation and a store of spare parts, can be made available to a qualified taker for essentially the cost of disassembly, removal, and transportation.
In general the cyclotron is made available "as is, where is" with no warranty or representation by the owner as to the suitability for any specific application. Of course, qualified, prospective takers are invited to inspect the machine, to examine service records, etc., and to bring in independent, outside consultants to help evaluate the system for their particular program needs.
Carroll-Ramsey Associates is glad to work with a prospective recipient to evaluate a used machine, pointing out areas where new or rebuilt parts may be needed to insure reliable operation. We will help supervise the dismantling and removal so as to facilitate timely restoration of the system, and we will supervise the re-installation and re-commissioning at the new owner's site.
We are also able to supply spare and replacement parts, whether they be standard commercial components, parts built from original design/fabrication drawings, or by re-engineering new and updated parts.
We can help the new owner as consultants on site planning and facility design, including shielding and radiation safety.
Carroll & Ramsey Associates does not accept any equity interest or commission in facilitating the transfer of used cyclotrons. We do our best to help the original owner to find a qualified recipient, then work as consultants on behalf of the recipient in providing the services outlined above. For example, we recently helped Mallinkrodt, Inc. of St. Louis, MO repatriate a used CS-30 cyclotron which had been used for PET isotope production at the University of Aberdeen in Scotland.
The way we work is exemplified by our recent participation in the relocation and successful restoration of a used TCC CP-42 cyclotron, which we helped move from M.D. Anderson Hospital in Houston to Denton, Texas. View Document (HTML) or (PDF)
Read Synopsis of Article "...Shipping a Used Cyclotron Overseas"
Getting the most out of an isotope-producing accelerator, as well as coping with those unusual, challenging, and urgent service situations requires that your key technical personnel have fundamental knowledge and understanding of the system, its various components, and their complex interactions.
We'll take you beyond rote instruction; we'll share our engineering know-how and experience and leave you with genuine insight. Carroll & Ramsey Associates provides in-depth Training for your lead operators and maintenance personnel. Learn about your accelerator from the people that designed and built it! We'll tailor a program to suit your staff's level of knowledge, need, and schedule requirements. (return to beginning)
Large cyclotrons, along with their beamlines and targets for commercial production of medium- to long-lived radioisotopes, have to be installed in thick, concrete-walled shielding vaults or bunkers.
Smaller accelerators used for the production of short-lived, neutron-deficient isotopes for PET, can be configured with self-contained surface shielding. We developed the concept and carried out the design and implementation of the radiation shielding used on the RDS-112 and -111 Radioisotope Delivery Systems, setting the world-wide standard for compact, efficient, self-shielded cyclotrons.
The design of a shield vault or a self-shielded accelerator for isotope production demands a thorough understanding of the underlying nuclear reactions, the strongly-coupled primary and secondary processes which produce the radiation, and the material properties, shielding attenuation factors, engineering trade-offs, and fabrication techniques involved in building the shield itself.
We have the experience, the insight, the codes and computational tools to help you develop an optimum solution. Contact Carroll & Ramsey Associates for help with your difficult accelerator and isotope-production radiation-safety and shielding problems. (return to beginning)
CRA Radiation Detector Systems are used as radiation exposure monitors inside hot cells and fume hoods, for flow-cell monitoring in HPLC and column-separation chemistry, and for monitoring radiochemical synthesis and labeling apparatus in radiochemistry laboratories.
Solid-State Radiation Detectors
In our medium- and high-sensitivity solid-state radiation detectors, the active element is a silicon PIN photodiode closely coupled to a compact, charge-integrating preamplifier (covered by USA Patent #'s 5,990,745 and 6,054,705), encapsulated together in a small probe. In applications where relatively high levels of radiation are encountered, gamma rays and x-rays are detected through direct interaction in the PIN photodiode itself.
Our medium-sensitivity detector probes operate in ac-coupled pulse mode, which provides excellent signal-to-noise ratio and--most importantly--blocks leakage current, substantially eliminating drift and instability due to changes in temperature. This is obviously and particularly important when measuring low activity levels.
For applications where the detector probe is closely coupled to concentrated sources containing relatively high levels (e.g. several tens to hundreds of millicuries) of high-energy, gamma-emitting isotope, temperature drift is much less of a problem. For these applications a simpler, lower cost detector is available which operates in DC-coupled mode.
High-Sensitivity
For analytic HPLC, gas chromatography, or any application requiring highest sensitivity and gamma-ray spectroscopy capability, we offer a new detector system built around a 1 cm3 CsI(Tl) crystal / silicon PIN diode /low-noise preamplifier module, in conjunction with a shaping post-amplifier, threshhold discriminator, and built-in ratemeter.. No additional amplifiers are needed--the power supply is included--just plug it in!
A gamma-ray spectrum from a 56Co / 57Co check-source is shown above. The prominent peaks are 122, 511, 846, and 1238 KeV. The noise floor is approximately 42 KeV.
The "DC" signal output from the system drives your chart recorder or computer data-acquisition system; the analog "pulse" signal output will directly drive your multi-channel analyzer.
Environmental Monitoring
For environmental or effluent-monitoring applications, a more sensitive (1 cm x 1 cm x 3 cm) CsI(Tl) crystal / PIN diode / preamplifier probe is available in a compact (1" dia. x 3" long) cylindrical package that can be easily "fished" through pipes and ducts. For highest sensitivity, we also supply a 2" x 2" x 1" CsI(Tl) crystal + PIN diode + preamplifier packaged in a (2.5" x 2.6" x 1.4") sealed aluminum can. Either probe is connected through a short length of coaxial cable to the chassis unit (same as described above) containing power supply, post-amplifier, threshold discriminator, and integrating filter.
Interested? -- See our CRA on-line catalog of radiation-detector products.
Application Note: "Scintillation Detector Applications Using Silicon Diodes"
Application Note: "Detection of X-ray and Gamma-ray Photons using Silicon Diodes"
Please call, write, or e-mail us for more detailed information and specifications on our radiation detector systems. (return to beginning)
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Telephone (510) 559-8153; FAX (510)559-8158
Mailing address: 950 Gilman Street, Berkeley, CA 94710