A non-absorbing detector is supposed, at least in theory, to report that a particle passes through it, though, the particle is allowed to exit the detector, s.t. we can do additional tests on it. No doubt, the non-absorbing detector "collapses" the wave-function, but additional detectors in continuation, may tell us in which state the 1st detector left the particle, which we can only guess we use absorbing detectors.
Now, does somebody know, do we have such detectors "on shelf", i.e. in practice?
Dear Mrs. Sofia D. Wechsler!
Could non-absorbing detectors be more useful in quantum tests, than absorbing detectors? - Of course, they will be more useful.
Если Вы сможете открыть тему по разработке непоглощающих детекторов в размере двух-трёх мл. $, то за 20 лет совестными усилиями мы с вами докажем их абсолютную полезность и может быть изменим закон сохранения энергии. Сами не сможем – юристы приедут, помогут.
Yours sincerely, Ivan Dolgov, 20170924 Д\д
Hopefully very very small gas filled detector (CONVENTIONAL) may act as almost non-absorbing detector when it absorbs little of deposited energy i.e. deltaE ---->0 in detector. Such detectors may have negligible efficiency. I wish all detectors used to detect 100's of MeV of gammas are practically non-absorbing detectors. For Quantum mechanical regime it will be interesting to know any such detector.
Dear @Ivan Ivanovich,
I am about to send you a message. Unfortunately, each time I place a question on RG, they block me for 2-3 days from sending messages.
So, I invite you to pay attention to RG messages in the next days. But, what I can already tell you is that I am not an industrialist, if you speak about financial investments, they are not in my possibilities. What I can do is to make theoretical proposals.
Best regards,
Sofia
Dear @MUNISH KUMAR,
I see on your profile page that you are an expert in radiation detection. I am no experimenter, so, I'd like to ask you some questions.
Please see, you speak in your comment of gamma detection. Well, if the efficiency is poor with gamma, what about alpha detection? A strongly charged particle may leave part of its energy in a medium, and get out of the detector through a back window. Then, can we have non-absorbing alpha detectors with not so low efficiency?
I am aware that inside the medium in the detector the alpha may be scattered, but since it is a charged particle, can we place near the back window collimators consisting in electric fields?
I am also aware that the alpha may attach one or two electrons, s.t. a further detection becomes less probable. Finally, as far as I know about cross sections, th more rapid is the alpha, the cross section of interaction with the medium is smaller. But my question is not if we can achieve very high efficiency, it is about non-negligible efficiency.
With best regards,
Sofia
Well, if the efficiency is poor with gamma, what about alpha detection?
As Such detectors not suitable for alpha as window thickness much greater than range of alpha.
A strongly charged particle may leave part of its energy in a medium, and get out of the detector through a back window. Then, can we have non-absorbing alpha detectors with not so low efficiency?
No, Even 10 MeV proton has range of
@Munish,
Then, no hope for non-absorbing detectors? Wow! You know, there are theoretical articles which rely on the existence of such detectors.
So, you say, if we want non-absorbing detectors we have to speak of gamma detectors, and take in consideration that their efficiency is poor?
With best regards!
Bubble chambers are "partially non-absorbing" detectors, because they allow many detection events for a single particle.
Measurement of one partner of an entangled pair measures the other partner as well without leading to its absorption. By entangling a particle with n others, you can make n measurements on the particle that do not lead to absorption, each measurement destroying the entanglement with the locally measured particle. Finally, you can make, besides the n non-local measurements an (n+1)st one, when the particle of interest is in a single-particle state and this will normally be absorbing. But the n preceding ones are non-absorbing.
@Klaus,
"Measurement of one partner of an entangled pair measures the other partner as well without leading to its absorption."
Yes, that's true, though non-rigorous. The correct formulation is: by measuring one partner, A, in an entanglement, one prepares the other particle, B, in a state specified by the wave-function on which one will measure B.
With this occasion I want to repeat something that I already said: to the studied particle is appended a macroscopic object, the bubble.
"Bubbles grow in size as the chamber expands, until they are large enough to be seen or photographed. Several cameras are mounted around it, allowing a three-dimensional image of an event to be captured. Bubble chambers with resolutions down to a few μm have been operated.
The entire chamber is subject to a constant magnetic field, which causes charged particles to travel in helical paths . . . " https://en.wikipedia.org/wiki/Bubble_chamber
The bubble is not a set of n particles as you say, and we don't get an entanglement of n+1 particles, where the (n+1)th particle is the one we study. Such an entanglement would still obey a wave-function - a complicated one - but it won't be a trajectory there. The wave-funcyion is a superposition of many possibilities of multi-particle trajectories.
But what is recorded on the photographic plate is not the particle, but the bubbles, the macroscopic objects whose centers-of-mass are aligned along one single trajectory.
From the multitude of possible trajectories allowed by the wave-function of the charged particle, at the contact with the macroscopic bubble one is picked (non-deterministically).
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