ALFMED stands for: Apollo Light Flash Moving Emulsion Detector (but also: Apollo Light Flash Experiment Medical Device), was one of the first devices built to investigate on the effects of cosmic radiation for humans in space.
From the early Apollo missions, but probably before, astronauts claimed to see flashes of light during their missions in space. It did not take long time to suspect that the cosmic rays were responsible for this phenomenon, however the physiological mechanism of vision was not so clear.
To verify and proof if were particles the cause of visual disturbance and to understand what stimulated the flashes of light seen by the astronauts was built ALFMED, an helmet equipped with nuclear photographic emulsions in order to verify and record the passage of the particles in the head of those who worn it.
ALFMED used a photographic plate mounted on a movable mechanism and one or two photographic plates in a fixed position. The astronauts had to wait fifteen minutes in total darkness before starting the experiment (dark glasses inside served as a shield to facilitate adaptation). Once ALFMED turned on, the movable plate began to move slowly, every time the astronaut (in contact with the mission center) saw the flashes of light, he informed the mission center so that every event was recorded (hour, minute and second of the event), the operation lasted about one hour. Once developed the film, through the comparison of the traces left by the particles in the emulsions and the data recorded during the experiment, was possible to check the exact moment of the interaction.
There was no longer doubt, cosmic rays were and are responsible for this phenomenon, also known as phosphenes. The early explanation was attributed to a Cherenkov radiation effect produced by particles in the eyeball. Although this may remain a possible explanation, other mechanisms seem to be more plausible, such as direct interaction with the retina of the eyes or with other components of the human visual system like optic nerve, neurons and interneurons.
The multiple interaction mechanism could explain the variety of events seen, indeed some seem to be like flash bulbs and other to be like moving objects as falling stars.
The ALFMED-R (replica) uses two Geiger Muller tubes placed one on each side, so that when worn they remain in close proximity to the temporal area (temples) of the experimenter. Two led lights (in front to the sunglasses) indicate the passage of particles in the tubes, right and left, and very probably in the head of the wearer. If a particle passes through both tubes and hence the head of the experimenter, there is the coincidence between the signals right and left and thus both the led are lighted. In this case also a third led (on the ALFMED-R front) will be lighted remarking the coincidence and therefore the passage of the horizontal particle.
Nevertheless there is a possible shower effect (say 30%), indeed the tubes (GMT) are placed side by side and not stacked, so that the coincidence may be detected for different particles that pass through the two tubes at the same time (is it possible to drop the shower effect to almost zero, just turning the head and ALFMED-R, 90° on a side).
Is possible to connect ALFMED-R with a cable to any computer and to use the AstroRad software to count the flow of particles
(see: http://www.astroparticelle.it/alfmed-replica.asp)
Why to build an ALFMED replica?
This replica of ALFMED can to persuade – if needed – the most skeptical people about cosmic rays phenomenon, in a let me say psichedelic way.
Rotated 90° on a side it works as a good cosmic rays telescope, that connected to a computer it can measure the flow of particles per unit of time. Connected with an EEG (electroencephalogram) can be used for experiments in quantum entanglement (we’ll see).
And if we want to overdo, carried this version of ALFMED into orbit has no reason to not work as well as the original ALFMED!
ALFMED REPLICA:
Detectors: 2GMT SBM19
Power supply: 2 x 1.5V batteries, 1 x 9V battery
Interface: USB 5V-TTL
Weight: 3.5 Kg
For further information please visit: http://www.astroparticelle.it/alfmed-replica.asp
Astroparticelle 