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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2
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1answer
22 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
23 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
votes
1answer
48 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
votes
0answers
29 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 ...
2
votes
1answer
77 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?
2
votes
3answers
168 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
votes
3answers
113 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
27 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
votes
5answers
235 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
83 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 ...
-1
votes
1answer
61 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
votes
2answers
2k 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
35 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
vote
0answers
28 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 ...
5
votes
1answer
370 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
votes
0answers
63 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
votes
2answers
571 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
votes
1answer
67 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
votes
0answers
46 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
votes
0answers
55 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" ...
6
votes
1answer
198 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
votes
1answer
44 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
vote
1answer
88 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
262 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 ...
3
votes
1answer
309 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 ...
1
vote
0answers
56 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
votes
2answers
106 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 ...
-1
votes
1answer
148 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 ...
11
votes
1answer
325 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 ...
8
votes
1answer
165 views

How to distinguish high-energetic muons and electrons in the CMS and ATLAS muon detectors?

At a typical energy of about 100 GeV, a muon has a Lorentz factor of about 1000, an electron about 200.000. The flight time to the detector should be around 30 ns (assuming d= 10m from the collision ...
4
votes
2answers
190 views

Energy measurement of W- and Z- bosons

W bosons decay into an electron and electron-neutrino or into a muon and muon-neutrino. The W lifetime is about $3 \cdot 10^{-25} s$, that means the decay occurs close to the collision point, not in ...
2
votes
0answers
78 views

How the dielectric rigidity depends on the shape of material?

A research article says that, "The conical shape improves the dielectric rigidity", but how I am not able to understand.
2
votes
1answer
138 views

How do micro-channel plates detect neutral molecules?

Micro-channel plate (MCP) detectors are used to detect photons, electrons or charged particles. But how can MCPs be used to detect neutral particles? In ion traps, the neutral molecules (after being ...
2
votes
1answer
2k views

What is Transverse Energy?

What is transverse energy? Why we use transverse total energy instead of energy and transverse momentum in place of Total momentum in the particle detectors?
3
votes
1answer
286 views

Explain background pattern in particle tracing image

I'm trying to understand this image of a particle tracing experiment (which can be found all over the net if you google for "bubble chamber"): ( There are two things that I can't figure out: The ...
3
votes
1answer
226 views

What algorithms are used for track reconstruction in cloud chambers?

In particular I'm interested in any algorithms that can separate multiple tracks from one another reliably.
4
votes
3answers
233 views

Does a Photon leave trace in a silicon tracker?

I am having this image from ATLAS Detector. In gray you can see the ATLAS's Si Tracker.In Green you see the Electromagnetic Callorimeter. In red there is the Hadron Callorimeter and in Blue there ...
2
votes
1answer
181 views

Understanding how mass spectroscopy works

Let me start by saying that I've posted this question here as well. I've posted it here because I think the questions I've asked involve the physics of molecules. So I’m trying to get a deeper ...
0
votes
0answers
52 views

The things to consider when choosing a mesh for an electron detector (MCP detector)

I am designing a electron velocity map imaging setup. I need a copper mesh just infront of the detector to accelerate the electrons towards the MCP detector. I am doing the instrument design for the ...
2
votes
1answer
62 views

How does a noseblow counter detect alpha radiation?

After working in air fed suits,operatives are required to give samples from their nasal passages by blowing their nose into a tissue,which is then counted in a noseblow counter. How does this work?
3
votes
1answer
74 views

Single electron non-perturbing detector

I am designing an experiment where I need to trigger the release of an electron by a radioactive source (Sr-90). The easy way to do it is to use a thin scintillator right after the source collimator. ...
2
votes
2answers
158 views

CERN projects on gravity

Recently I was reading about CERN's upgrade to work on gravitational theories. But if most of the work has been done by General Theory of Relativity than with other theories are there that need to be ...
6
votes
1answer
111 views

Measuring nucleons using electron beams

sorry if the question is too elementary. From: The Britannica Guide to Particle Physics: The sizes of atoms, nuclei, and nucleons are measured by firing a beam of electrons at an appropriate target. ...
1
vote
1answer
116 views

Where can you get a photon detector?

Say I'm doing the double-slit experiment with photons as the particle and want to add a detector just behind each slit to eliminate the interference pattern. Where would I get a detector like that?
0
votes
2answers
202 views

How to choose a $\alpha$, $\beta$, $\gamma$ measurement detector?

There are many different detectors for different radiation,such as NaI,HpGe,CsI for $\gamma$ detection,and ionization chamber,proportional counter,Geiger counter for $\alpha$, $\beta$ detection,but ...
2
votes
3answers
142 views

New physics at high energies, cosmic rays, particle-detectors in space

New physics is expected at high energies and cosmic rays have high energies, so have there been or are there any plans to put particle detectors in space to study cosmic rays for new physics ?
1
vote
0answers
211 views

How do I calculate the Radiation length of a Molecule

I want to calculate the Radiation length in a Molecule with the Formula given on wikipedia. How do I calculate Z and A for a molecule to put it into the Formula?
3
votes
1answer
188 views

Cloud chamber video showing large particles - What are they?

Watching a video of a cloud chamber on wikipedia (http://en.wikipedia.org/wiki/File:Cloud_chamber.ogg), I cannot help noticing the large collisions that take place at 00:12 and 00:24. What are ...
3
votes
0answers
94 views

Proton flux model or data at energy range up to 100 keV

I am looking for a model or at best the database of proton fluxes (solar p+) at a energy range of some eV up to 100 keV. I have already found the SOHO database: http://umtof.umd.edu/pm/ But the ...
6
votes
2answers
4k views

What is p_T? (transverse momentum?)

I've been looking at a few papers in experimental physics (from the ATLAS collaboration, for example) and I've often run across phrases such as "high-p_T electron." What exactly is p_T? Is it simply ...