filling in the unspecified details of elegant-sounding descriptions of experimental methods.

learn more… | top users | synonyms

3
votes
2answers
77 views

How to measure transverse current-current correlation at arbitrary wave vector and frequency

Let $\hat J^{\mu}(t,\boldsymbol r) \equiv (c \hat \rho(t,\boldsymbol r), \hat{\boldsymbol J}(t,\boldsymbol r))$ be the density-current operator at spacetime coordinate $(t,\boldsymbol r)$, in the ...
0
votes
2answers
55 views

Creating nanosecond pulses from a CW laser source

Experimental setup question. If anyone aware of a technique to create pulses of several nanoseconds at a around 10Hz repetition rate from a CW laser source?
5
votes
1answer
356 views

How does one align a laser using two adjustable mirrors?

Suppose we would like to get a laser beam to pass through a particular point in space in a particular direction. At our disposal we have a laser, two adjustable mirrors (can rotate up/down and left/...
2
votes
1answer
46 views

High $p_T$ and high $Q^2$ in deep inelastic hadronic collisions

When reading about high energy collisions (for example proton-proton collisions at LHC), I always find the relation $Q\sim p_T$, which, for me, is hard to demonstrate. Moreover, I found statements ...
2
votes
1answer
142 views

Good algorithm for in-experiment 1-D optimization?

I'm running an experiment -- for the question, it doesn't matter which one, but I'm measuring an optical intensity $I$ as a function of two parameters: reflection angle $\theta$ and wavelength $\...
1
vote
1answer
34 views

Is it possible to measure the resistivity of something using A.C. Current and a capacitor?

I've read that A.C. current "passes" through a capacitor. Is it possible to use this and measure the resistivity of the medium between the plates? Any sources or links would be appreciated.
1
vote
1answer
94 views

Uncertainty of approximately sinusoidal voltage measurement

Say one is interested in measuring the mean value an approximately sinusoidal voltage with an instrument that has an accuracy of 0.01 V, according to its spec sheet. 10 periods of the oscillation have ...
0
votes
1answer
22 views

Pound-Drever-Hall frequency stabilisation technique

I am having some difficulty understanding the Pound-Drever-Hall frequency stabilisation technique, when locking a laser to a stable cavity. As far as I understand: We emit the laser frequency, f0....
0
votes
1answer
47 views

why am i getting lower mass after melting iron dust?

I've been trying to melt iron dust for a long time but after melting I lose a lot of mass. Any idea what is causing this? I've used gas and electrical arc to melt the dust.
0
votes
1answer
36 views

measure barometric pressure using boiling water

I have set a cup of water in a bell jar, with a thermometer. I am able to lower the pressure until the water boils and I am able to measure the temperature of the water simultaneously. I then looked ...
0
votes
1answer
41 views

prototyping a cyclotron , a charging problem

I'd like to model a cyclotron but not with subatomic particles but with a small metallic ball but the problem is i need to charge the metallic ball with certain amount of charge and i must know it to ...
0
votes
1answer
22 views

How to experimentally identify the exposed face of a crystal?

After depositing a material (e.g, TiO2) on a substrate, what methods can I use to check whether the material is crystalline, and what face (e.g, 001, 101, etc..) of the crystal is exposed?
25
votes
0answers
847 views

Are the fast axes on Thorlabs quarter-waveplates mislabeled?

Some members of my lab are performing a polarization-sensitive experiment where they need to use a quarter-waveplate (QWP) with the fast axis in a specific direction. In the process of carefully ...
5
votes
0answers
219 views

Parity and Helicity of the Higgs Boson

I have been studying how the spin and parity of the new boson discovered at the LHC will be studied and have run into some confusion. The Standard Model Higgs is expected to be a scalar (i.e. have ...
3
votes
0answers
62 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 ...
3
votes
0answers
173 views

Production vs. Collection, and Contaminants vs. Depositions, what might be missing in cold fusion research

I though cold fusion and LENR were discredited, but just a few days ago I found out that NASA is claiming LENR is real. So I thought if they're detecting something, what could it be, and why wasn't it ...
3
votes
0answers
167 views

Obtaining point of application of Ground Reaction Force with use of a hyperstatic load-cell array platform

I'm looking for the theory of an experiment that is giving me a hard time to perform. I have an instrument composed of a rigid horizontal square plate rigidly supported under each corner by a load-...
2
votes
0answers
13 views

Have the BaF2 scintillators a strong correlation with the alimentation current that cause the shifting of the centroids in the distribution?

In gamma gamma correlation I suspect the presence of systematic error maybe caused by a non optimal alimentation voltage according to someone there is a quadratic correlation between centroids ...
2
votes
0answers
24 views

Creating a structural dynamic model using only modal test data

Short version: Suppose I excite a vibrational response in some structure and measure its mode shapes and natural frequencies. Is it possible to create a structural dynamic model of the structure ...
2
votes
0answers
40 views

Determining the spatial imaging resolution based on a pinhole diffraction pattern

I aimed a 780 nm/1mW laser at a 1μm pinhole and took a picture of it using a lens and a CCD camera. The magnification of my imaging system is ~25 times. I wrote some code that takes the image of the ...
1
vote
0answers
28 views

Galileo's pendulum and any references

In some texts about the simple pendulum we use to see references about some "experiments" Galileo Galilei did realize and whereby he found some important results, including that the period of the ...
1
vote
0answers
10 views

Anoxic sample containers

I am preparing pure Si samples, etching the oxide layer, in an argon glovebox, and I have to transfer them to the AFM. We don't have any sample containers in the lab, so I have to buy some. I wasn't ...
1
vote
0answers
26 views

Procedure for wrapping a superconducting coil around a cylindrical shell?

I don't know if experimental physics questions are allowed on this site - please direct me to the proper SE if it doesn't belong here. I need to wrap a few layers of superconducting wire (~80 ...
1
vote
0answers
34 views

How is it possible to combine various techniques in cold atom experiments?

I’ve been reading about laser-trapped cold atoms (6Li in particular, which is a fermion) and was amazed at the number of things to keep track of in the experiments, just to gain that degree of control ...
1
vote
0answers
40 views

Can water seep in?

Today morning I was sweating a lot, and a drop of it directly fell on my iPhone's home button. Considering the height of fall to be approx. $30 cm$, I started wondering whether water could seep in. ...
1
vote
0answers
56 views

Kirchoff's voltage law doesn't seem to hold in an experiment conducted with series resistor, diode and signal generator

I've conducted an experiment to look at the electronic characteristics of a diode. This was done using a series diode, resistor ($R$) and signal generator. The signal generator was made to supply a ...
1
vote
0answers
306 views

Help understanding Fizeau's calculation of speed of light

While searching for different methods of calculating Speed of light, I came across one of the methods that Fizeau discussed below which I cannot fully understand. In short, in Fizeau’s apparatus, a ...
1
vote
0answers
37 views

Using GPS Satelites as dark matter detectors

Recently, two scientists have proposed a new way of detecting dark matter, using GPS Satellites. A part of the article is posted online: Hunting for topological dark matter with atomic clocks. Can ...
1
vote
0answers
52 views

What is the error on measuring the phase of a sine wave?

Let's say I have a wave, with frequency $\omega$ and phase $\phi$, of the form: $$y(t) = 1 + A \sin(\omega t+\phi)$$ where $A < 1$. I have measured this wave N times, and we can assume these ...
0
votes
0answers
32 views

how can I detect cosmic muons from background?

Is there anything I should be careful with if I would like to detect muon at sea level? Noise background? Threshold? Even signals from other particle with stronger flux rate?
0
votes
0answers
27 views

What difference does it make if the turns in a tesla coil overlap?

Would a tesla coil in which the primary coil is made by overlapping the turns of the wire work?
0
votes
0answers
14 views

Measurement of Quantum Hall Effect

I'm somewhat confused about the original measurement of the QHE in a Si-MOSFET, which might stem from my not understanding MOSFETs very well. In their measurement, von Klitzing et al. measure the ...
0
votes
0answers
37 views

How are optical lattices created, and how big can they be?

I am asking about the basic concept and the schematics of the laser configuration. How are atoms forced to stay in optical lattices? What lasers (power, wavelength, etc.) are used, and how are they ...
0
votes
0answers
20 views

What is needed to be taken into consideration when measuring torque in dynamic mode?

Let's consider a DG generator connected with a hydraulic turbine through a shaft. To the stator of the generator it's attached a arm connected to a load cell. The load cell is measuring the force that ...
0
votes
0answers
19 views

Interferences while using two ToF cameras

Im using two time-of-flight (ToF) cameras, a DS325 from SoftKinetic and a Creative Senz3D, at the same time with the DepthSense-SDK and the Point-Cloud-Library (on Ubuntu 15.04). But I got strong ...
0
votes
0answers
53 views

How big can be gradient of magnetic induction (in lab)

I'm thinking about magnetic levitation and how big force can push a diamagnetic when we put it in inhomogenious magnetic field. As far as I know, force exerted on a diamagnetic is proportionald to $\...
0
votes
0answers
182 views

Measuring a quantity using two measuring devices

I would like to ask how I can reduce uncertainty by designing an experiment. I need to measure a quantity( say speed, in m/s). I have to calibrate the device and then move the device to measure this....