instrument rack for nuclear physics experiments
Date: circa 1980
Inventory Number: 2003-1-0269
Classification: Instrument Rack
Dimensions:183 x 68.6 x 58.4 cm (72 1/16 x 27 x 23 in.)
Accessories: large copper template (3), large circuit board (3), black metal frame (3), metal connectors, Texas Nuclear booklet, catalog sheets from RIDL, a plastic 12-inch ruler
DescriptionA tall metallic rack is filled with an assortment of counters. The upper level is filled with Nuclear Instrumentation Modules (NIMs). Here is the list:
(2) EG&G Stretcher Amplifier, Model AW 105. They both have been engraved "WAPP" (for Wide Angle Pair Production) and have small pieces of tape to mark special adjustments on dials.
(1) EG&G Coincidence Counter, model C104. "WAPP" is engraved on it.
(1) EG&G Gate Generator, model GG200. A piece of paper indicates that it was the "Property of / Cyclotron Lab".
(2) EG&G HV Pulser, model HV100. A white sticker mentions "New Krypton / Aug 17 [strikethrough] 21 1968"
The middle level of the rack is made of two modules, which appear to be from a generation before the upper ones. The larger one is an analyzer made by RIDL, model 34-12. One piece of tape, near a dial, says "1K Max / Jan 80".
The lower level of the rack is made of a series of RIDL modules.
(1) RIDL model 30-19. A tag mentions: "U.S. Government Property / USN 1866-S-282" Another tag says "Princeton-Penn / AP-004054 / Accelerator.
(2) RIDL model 33-10B. A sticker mentions "Harvard University / Dept. of Physics / NSF Equipment.
(1) RIDL model 30-19
(1) RIDL model 54-6
The tags attached to the various modules gives a good sense of how these sorts of instruments were used over rather long periods of time and how they were cannibalized from one kind of physics experiment to the other.
Signedmultiple signatures, see description
Inscribedyellow stickers (3): Harvard University / Physics Dept.
yellow sticker: Harvard University Physics Dept. / M. I. Sc.
yellow sticker: Proton Biomedical Group / Harvard University Physics Dept
yellow sticker: Harvard University / Dept. of Physics / NSF Equipment
yellow sticker: Harvard University Physics Dept. / Cyclotron Lab
tag attached to a string: Please Note – / Yellow color-coded BNC connectors indicate outputs / which must be terminated in 50 [ohms] for proper operation / of the instrument / Green color-coded BNC connectors indicate protected / data inputs for analog signals.
FunctionExperiments with cloud chambers relied heavily on photographic images, whereas those with cyclotrons employed logic circuits.
When a high energy beam of particles collided with a target, it triggered thousands of events and scattered particles and photons. These were picked up by detectors, which in turn sent electrical signals (or pulses) to a wide assortment of logical devices for analysis. Logic instruments included count-registers (or scalers), which counted up the events; pulse height analyzers (PHA), which selected and sorted pulses that fit within certain sized windows; and coincidence counters, which recorded simultaneous events.
Historical AttributesThis rack was assembled and used by Andreas Koehler in his osteoporosis experiments using a live cat as a proton beam target (unharmed by the tests) to explore non-invasive means of checking for bone calcium levels. Harvard Cyclotron Laboratory, c. 1980-1984.
ProvenanceHarvard Cyclotron Laboratory
Related WorksPeter Galison, Image and Logic: The Material Culture of Microphysics (Chicago: The University of Chicago Press, 1997), chap. 6.