the tools used to detect (and sometimes) characterize ionizing radiation. This tag is appropriate for question about the characteristics and behavior of all such devices from the simplest Geiger-Muller tube, to the compound monsters used by high-energy experiments to the mega-ton instrumented volume ...

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1answer
23 views

Why are high energies needed in collision experiments?

Why are high energies needed in collision experiments? I believe it has something to do with the interactions needed between particles to find other particles only happening at high energies? Is this ...
0
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1answer
69 views

Does elementary particle emit photon?

Charged particles are accelerated by the magnetic field in a particle collider before allowed to smash together at specific location where the detectors are housed. My question is do the ...
7
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3answers
259 views

Fiducial volume in collider/detector physics

I'm trying to make some sense of ATLAS measurements for a personal project to learn how to use Pythia, and part of my work requires me to recreate the distribution for Z boson decay. I encountered the ...
1
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1answer
43 views

Predict spread of signal peak in particle physics experiments, due to detector resolution

I am working on an LHCb experiment, in particular the $B^0 \rightarrow K^{*0} \gamma$ decay. The $K^{*0}$ decays into $K^+$ and $\pi^-$. So the decay products of the decay are $\gamma, K^+ $and $ ...
4
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1answer
39 views

Is it possible to use hot cloudy water as a cloud chamber?

This morning I got some warm water from the shower head to a dark plastic basin to wash some sensitive clothes. During the process lots of tiny bubbles got into the water so it had a cloudy ...
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0answers
10 views

Are there any particles emitted by the sun that can be observed in a Wilson cloud chamber?

Are there any particles emitted by the sun that can be observed in a Wilson cloud chamber? Are there better hours of the day/time of the year to see them? More generally, is there a list of cosmic ...
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0answers
25 views

Difference betwen combinatorial and correlated background in particle physics?

What is the difference, in particle physics experiments, between combinatorial and correlated backgrounds?
4
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1answer
64 views

Rejecting background in $B$-meson decay

I want to reconstruct the $B$ mass from the decay $$ B^0 \rightarrow K^{0*} \gamma \quad\text{ where }\quad K^{0*} \rightarrow K^{+} \pi^{-} $$ and the equivalent antiparticle decay. A key element in ...
0
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1answer
46 views

Trace of gamma particle

Can we have a detector, making traces of gamma particles (gamma photons) visible? Usually they are invisible until pair born or something. UPDATE G-M tube can detect gamma particles. Can we put ...
0
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1answer
33 views

Particle physics plots: on the x-axis, Mass or (Mass)$^2$?

This might be very silly, but I have seen particle physics graphs plotted against $mc^2$ and others plotted against $(mc^2)^2$, which is actually the invariant $p_{\mu}p^{\mu}$. Is there a physical ...
2
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1answer
52 views

Why, in particle physcis experiments, the background is sometimes a decaying exponential?

Take, as an example, the Higgs boson finding: But the same is found in many other particle physics detector graphs... **Why is the shape of the background a decaying exponential? ** At least ...
2
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1answer
37 views

“Double-counting” in particle detectors

Apparently, when analysing events from particle detectors, one may incur in double-counting, which happens when a physics object appears as a single object of its own type, but it may also be ...
1
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2answers
253 views

How are quarks and leptons detected experimentally?

How are quarks and leptons (including subatomic particles) detected in the laboratory,especially when most hadrons and leptons have a lifespan for a considerable small amount of time?Also how do we ...
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2answers
52 views

Photon yield of NaI

We have to calculate the photon yield of the scintillator NaI. We have measured his pulse height spectrum but we have no idea how to solve this problem. Can someone explain it? The source that we used ...
1
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2answers
117 views

can we detect the photons in the interaction of two charged bodies?

if the interaction of two charged bodies is through the photon exchange: 1) how much is the energy of these photons and how do we calculate their energies? 2) can these photons be detected by a photon ...
0
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0answers
48 views

Do twice more atoms absorb twice more photons?

Let's assume you have a photon detector that detect individual photons striking it when exposed to a weak light source. Now let's assume you somehow managed to make a denser detector from the same ...
1
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0answers
77 views

Radiation Safety of some Particle Accelerators in CERN?

I am trying to study the radiation safety and what kind of roles are required there with particle accelerators. Radiation safety groups of CERN is here. I contacted their a few members of them. I ...
1
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0answers
23 views

How would gravitons be detected? [duplicate]

How would gravitons be detected indirectly or directly, in space or on earth? And what experiments are going on to find gravitons?
0
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1answer
67 views

Convolution of Gaussian with exponential decay?

I need to convolve an exponential decay (defined as the exponential $Ae^{-\lambda t}$ from $0$ to $+\infty$) with a Gaussian of known standard deviation $\sigma$, in other words I need to compute the ...
0
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0answers
12 views

What is 'transparency rate' for ionization chambers?

I was reading a paper a little while ago and I saw that the author noted the 'transparency rate' of an ionization chamber. The ionization chamber had field shaping wires at the entrance and exit that ...
1
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1answer
43 views

Using tracking detector in a double slit experiment, what would we see?

Let's say we put tracking detector (eg. a cloud chamber or a more advanced device) behind the double slits. What would we see? I think the interference pattern is three dimensional. So there are ...
2
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1answer
44 views

How doesn't an ionization chamber leak?

I'm sure my understanding of an ionization chamber is incorrect, so please point out the error. Suppose we are using an sealed ionization chamber to detect the energies (trajectories) of a particular ...
0
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0answers
37 views

Why remove hard processes from a particle physics experiment

"2.2.2 The kt algorithm in e+e− The use of the minimal energy ensures that the distance between two soft, back-to-back particles is larger than that between a soft particle and a hard one that’s ...
0
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1answer
53 views

Resolution of experiment is lower than the detector, so how to weigh the data?

I am attempting to create an atomic model based on data from a transmission electron microscope (TEM). Basically you shoot electrons at bunch of identical molecules stuck to a grid, and look at the ...
3
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0answers
37 views

Sensitivity of Cloud Chamber

I have been watching some videos on cloud chambers: https://www.youtube.com/watch?v=Efgy1bV2aQo and they are quite amazing. What I can't figure out, is why aren't these chambers over loaded with ...
1
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1answer
81 views

Neutrinos at Super-Kamiokande

Why did the Super-Kamiokande experiment detect half the number of neutrinos emanating from below the earth as from above it?
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3answers
217 views

Detecting negative energy products in particle accelerators

Are the detectors in a typical particle accelerator experiment, either in Fermilab, or now in LHC, sensitive to negative energy particles? How would a negative energy particle, (say, a negative ...
4
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3answers
192 views

How can a detector distinguish between a photon and a gluon

Considering that both gluons and photons have no mass, no charge and spin 1, I was wondering how one can tell the difference, if they hit a detector after a collision at the LHC. I know that gluons ...
2
votes
1answer
58 views

Why Microchannel Plates can be operated only in vacuum?

Why it is said that the Microchannel Plates can be operated in vacuum? What is the maximum pressure in which it can be operated? Also, while it is not operating, should it be kept in vacuum? Is this ...
4
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5answers
277 views

Effect of wavelength on photon detection

When some photon detector detects a photon, is it an instantaneous process (because a photon can be thought of as a point particle), or does the detection require a finite amount of time depending on ...
4
votes
1answer
114 views

How use the Higgs branching ratio plot to extract information about the Higgs mass compared to experiment?

What does the plot of higgs branching ratio (see figure below) say about the higgs mass anyway? How can one use it as a guide to find the higgs mass experimentally? If we e.g. go to $M_H=126$ GeV ...
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1answer
82 views

Lifespan of particles

After reading a very informative tutorial on elementary particles physics over at http://www.particleadventure.org, I have a question I can't figure out. I understand the need to accelerate a ...
8
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2answers
3k views

Which is the smallest known particle that scientists have actually *seen with their eyes*? [closed]

Which is the smallest particle that has been actually seen by the scientists? When I say "actually seen", (may be using some ultra advanced microscope or any other man made eye, using any wavelength ...
0
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0answers
41 views

Quantum Hall Effect Dark Matter Detector?

Has anyone used a Quantum Hall effect detector to detect dark matter? I was looking at the following animation on wikipedia: ...
1
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0answers
31 views

Superconducting loop as a particle detector?

Imagine that one has induced a persistent current in a superconducting loop. If a particle interacted with an electron in one of the Cooper pairs then would some decoherence and dissipation occur? I ...
6
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1answer
937 views

How does one detect a single photon?

I understand the double slit experiment up until the point that we begin "detecting" single photons. What does it mean to detect. You cant place a camera in the slit because that would capture the ...
2
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0answers
117 views

What does it take to recreate double slit experiment with detectors?

Is there anyway to recreate this experiment with detectors at home? I want detectors because I want to get non interference pattern too. I have a little know-how in electronics so If I need to buy a ...
8
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2answers
640 views

Does a muon detector on Earth's surface correctly measure the mean lifetime of a muon?

Just a simple question. Does a muon detector on Earth's surface correctly measure the mean lifetime of a muon? I would think the answer is no because most muons detected are created about 15 km above ...
3
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1answer
89 views

Why apply voltage on an Si detector only on atmosphere or high vacuum

The general instruction when using a silicon detector is to either apply voltage only in atmospheric pressure or in high vacuum. Not in between! I can't find a physical answer to it. Why is it so ...
3
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0answers
52 views

Alternative ways to take particle tracks photographs in a cloud chamber

I know that the most common type of particle tracks photography is in photographic plates, but i'm using a cloud chamber and I would like to know if there are alternative ways to take photographs of ...
0
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0answers
58 views

Compare Dynamics of Cosmic Ray Neutron Radiation

Examining cosmic ray neutron radiation near ground by neutron monitors for example (http://www.nmdb.eu), different stations show similar dynamics in the signal. At one station, I like to "substract" ...
7
votes
1answer
265 views

Is it feasible to measure the energy of cosmic ray muons with a consumer Digital Single Lens Reflex camera?

I have read this article SIBBERNSEN, Kendra. Catching Cosmic Rays with a DSLR. Astronomy Education Review, 2010, 9: 010111. and it talks about estimating the muon cosmic ray flux by means of a DSLR ...
0
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1answer
48 views

What is the nature of Young's Double Slit Experiment with detectors?

If a detector is kept at the two slits the fringes disappear. But, when the detectors are removes do the fringes come up immediately without any significant time lag? Can there be a way to switch on ...
1
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1answer
93 views

What is the state of the art in particle detection and localization

I am researching methods to detect the position of radioactive materials (emitting gamma and beta particles), and would like to know what current methods are used to do this. What type of sensors are ...
3
votes
1answer
530 views

How to measure (missing) transverse energy

There is traditionally a bit of confusion between missing transverse energy, and missing transverse momentum. I've seen both used interchangably, and sometimes even things like "$\not E_T = -|\sum ...
4
votes
1answer
793 views

Neutrinos arrived before the photons (supernova)

A while back I read about the super Kamiokande detector detected a large neutrino flux and then several hours later a supernova was seen. Anyone know of this with sources? I don't recall the source at ...
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0answers
57 views

Recover activity from photo at Fukushima

This photo was published at stern magazine online. I wonder which information about the physical quantities could be reconstructed or computed given this photograph, the exposure time, and the ...
6
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2answers
112 views

Deciding what to collide at particle accelerator

Different particle accelerators use different types of collisions. For instance at the LHC they investigated p Pb collisions while its predecessor (LEP), used to collide electrons with proton and at ...
0
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1answer
217 views

How does a synchroton work?

I know that a linear accelerator (linac) works by having terminals that get longer progressively and changes polarity due to AC current. And I also know that a cyclotron works by having two ...
12
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1answer
382 views

Operator that describes particle detector

In non-relativistic QM, the position of a particle is an observable. In QFT, fields are the observables. However, particles must have some sort of position, otherwise we wouldn't see pictures like the ...