What's New at Carroll & Ramsey Associates?

Credit Cards now Accepted

We are now (finally!) able to process credit card purchases for our detector products, small parts, and accessories. We accept VISA and Master Card. Eventually, we will be set up to conduct e-business on-line, with the usual 'shopping cart' protocol, etc. However, for the time being, all credit card sales transactions are being conducted directly by telephone or FAX. Please contact us by 'phone or e-mail to verify product description and price. Then, if you wish to order by credit card, fill out ourcredit card order formand fax it back to us.

New Products, now available from CRA

1) As we first reported at the International Symposium on Radiopharmaceutical Chemistry in Sydney, Australia (ISRC 2003), we have developed a two-position target-switching apparatus which is compatible with standard RDS-112 targets and which fits within the space constraints imposed by the closely-fitting cyclotron shield. download poster-presentation -- beamposter.pdf (2.5 Mbyte) The switcher allows the user to utilize a fifth target -- i.e., to switch between two standard targets plus a beamstop mounted on a single beamline -- without opening the shield. The target-switcher bolts to the main vacuum tank, taking the place of beam-pipe #2. The system also incorporates a new, more durable collimator design for improved power dissipation and greater reliability compared to the original RDS-112 collimator design. The photograph immediately below shows the target-switcher's bare 'chassis' without targets or mechanical actuators. The next photograph shows the complete, functional system now installed on the RDS-112 cyclotron at The University of Southern California.

2) We have delivered a new beamline accessory for cyclotrons: Our Model 412 adjustable collimator system.

The system is primarily intended for research and development on cyclotron targets. The collimator is inserted just ahead of the user's target or target changer. The unit provides 6 different aperture settings of 4 mm dia. through 9 mm dia. in 1 mm steps.

The collimator is implemented as a motor-actuated rotating aluminum drum, controlled remotely from the user's control center. The collimator drum is water-cooled and isolated from ground so that collimator current may be monitored at the control panel. Water-cooling and collimator over-current safety interlocks are also included.

Questions? Please contact us at collimator@carroll-ramsey.com

3) Our newest radiation detector product: EZ-SCANtm; a compact, benchtop scanner / detector system for thin-layer chromatography. EZ-SCAN Brochure -- 500 kbytes

The system comes equipped with our OMNI-RAD® detector -- a versatile, PIN-diode-based module for scanning the commonly-used medical and research isotopes, including positron-emitters such as 18F, or beta (-) emitters such as 131I, as well as low-to-medium energy photon emitters such as 125I, 99mTc, or 123I.

This new, multi-purpose detector (which may also be sold as a separate, stand-alone module) operates in either of two modes:

1) As a beta detector -- a pair of -connected (opposed-polarity), back-to-back PIN-diodes mounted behind a 3 mm wide x 15 mm long aperture in a 6 mm thick Pb shield provides excellent spatial resolution with beta + (positron) or beta (-) emitters, but without the need for bulky lead shielding -- even in the presence of an intense gamma background.

2) When the diode signals are summed instead of subtracted, the module functions in photon-detection mode for use with the low-to-medium-energy gamma or x-ray emitters.

The scanner accommodates TLC plates up to 20 cm long. The unit is compact: The chassis base is only 12" wide x 8" deep x 3.5" high. The scanning bed extends 4" to the left of the base at the beginning of a scan, and 4" to the right of the base at the conclusion of a full (20 cm) scan.

A terminal strip on the back of the scanner base provides auxiliary contact closures ( "start" and "stop" ) used in conjunction with an external recording device. The OMNI-RAD® detector module puts out an analog signal (0-5 V) which is connected to the user's chart-recorder, or to a computer-based chromatography data-acquisition system such as PeakSimpletm.Download OMNI-RAD Brochure -- 500 kbytes. For customers in the European union view OMNI-RAD 'CE Declaration of Conformity'.

9th International Workshop on Targetry and Target Chemistry

This meeting was held in Turku, Finland from May 23 - 25, 2002. I gave the first evening's 'welcome' speech on Commissioning and Decommissioning Used Cyclotrons, along with some advice on dealing with neutron-induced activation of concrete in a cyclotron vault. In addition, I presented two posters: one on our solid-state detector products, the other on the neutron source term for PET targets.

Download 'Commissioning and Decommissioning Used Cyclotrons' Slide Show (PDF -- 2.0 Mbytes)

download 'Source-term' PDF

download 'Solid State Detectors' PDF (2.57 Mbytes)



1) U.S. Patent Number 5,990,745, entitled Discharge Element for Charge Integrating Preamplifier was issued to L. R. Carroll on Nov 23, 1999. This patent teaches a novel method for eliminating the high-ohm feedback resistor (1 gig-ohm or more) which is usually required for low-noise performance in FET charge-integrating preamplifiers used for x-ray and gamma-ray spectroscopy.

2) U.S. Patent Number 6,054,705, entitled Charge-Integrating Preamplifier for Capacitive Transducer was issued to L. R. Carroll on April 25, 2000. This patent teaches a new and novel method for implementing simple, compact, low-power charge-integrating preamplifiers for use with Silicon diodes, or similar devices, which are widely used as radiation detectors -- either directly or in conjunction with a scintillating crystal such as CsI(Tl).