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

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11
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3answers
5k views

How to prolong life of liquid nitrogen in hosehold vacuum flask?

I need to do some work with liquid nitrogen at home. The main question is how to store it without buying huge vacuum flask specifically for liquid nitrogen. I've tried to use usual steel household ...
6
votes
2answers
230 views

Are there solid materials with controllable porosity?

In analogy to piezoelectric materials, where the application of an electrical field creates mechanical deformation in the material, I have the following question. Are there solid materials whose ...
0
votes
0answers
156 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 ...
5
votes
1answer
651 views

Atoms' excitation energies as derived from Frank-Hertz experiment data

I'm analyzing the experimental data obtained during Frank-Hertz experiment (conducted with Hg atoms): Accelerating voltage values were multiplied by 0.1 during measurement (i.e. the mean value of ...
3
votes
1answer
432 views

Frank-Hertz experiment setup

The usual schematic representing the setup of Frank-Hertz experiment is the following: However, sometimes, you can see a bit different schematic: My question is: what function does $V_{G_1K}$ ...
14
votes
3answers
1k views

How should I clean a part before installing it in a vacuum system?

What are proven procedures for preparing a part that comes fresh out of the workshop for ultra-high vacuum (UHV) and extremely-high vacuum (XUV)?
10
votes
2answers
1k views

Methods to stabilize and maintain extremely low humidity in a lab environment

My atomic physics lab is in a building that experiences huge swings in humidity levels during the year due to the monsoon season Our building provides temperature, but not humidity control. Using ...
0
votes
1answer
72 views

Uncertainty in approximated relation

I'll give directly an example to fix the ideas. Suppose that you're studying the acceleration of a system of masses that depends from the number $n$ of masses $m$ by the following relation: ...
2
votes
1answer
76 views

Creating a stream of single file atoms

How do you go about creating a stream of single file atoms? The aim is to fire a stream of single file atoms (hydrogen, helium) down a vacuum and detect there arrival on the opposite end. Any ...
3
votes
1answer
122 views

Galaxy Kinematic Fitting: How to deal with Point Spread Function (PSF)

The past few months I have been studying astronomy and Integral Field Spectroscopy (IFS). What I want to do is to fit a galaxy kinematic model to data (ie: estimate the model parameters that give the ...
3
votes
1answer
103 views

Time of Measurement Vs Number of Measurements

Let's say that an experiment has to determine the number of cosmic muon at sea level. The appropriate equipment is ready to measure the counting rate. I can think of two ways Count for 10 minutes, ...
5
votes
2answers
776 views

Optics alignment of a confocal scanning microscope

I am facing a challenge in my project regarding optical alignment. See the figure: The challenge is with the vertical optical system alignment. I considered placing a mirror and check back if the ...
10
votes
2answers
757 views

Mechanical Equivalent of Heat

Recently I have been looking up James Joule's experiment regarding the mechanical equivalent of heat. After viewing some drawings of the apparatus, I assumed that the lines holding the weights would ...
4
votes
1answer
196 views

How important is it, really, to clean vacuum parts?

In every lab I've seen, people are quite meticulous about cleaning parts that are to be used in ultrahigh vacuum, as well as the components of the chamber itself. The parts may be put in an ultrasonic ...
3
votes
0answers
163 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 ...
2
votes
1answer
399 views

Experimental measurement of volumetric flow rate

The other day I with my team had to measure the volumetric flow rate through a pipe only using a 2000 mm$^3$ volumetric flask and a chronometer. The end of the pipe discharged to the atmosphere. As we ...
5
votes
2answers
4k views

Multiple measurements of the same quantity - combining uncertainties

I have a number of measurements of the same quantity (in this case, the speed of sound in a material). Each of these measurements has their own uncertainty. $$ v_{1} \pm \Delta v_{1} $$ $$ v_{2} \pm ...
3
votes
1answer
274 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.
0
votes
1answer
885 views

Experiment to measure initial speed of high speed tennis ball?

I want to devise a way to measure the initial speed of a tennis ball fired from a tennis ball cannon, but without using any speed-measuring devices. Just plan distance-measuring and physics formulas. ...
2
votes
3answers
670 views

Glass pipe cutting

I want to know how to quickly create the straightest possible breaks in glass pipes I apologise if this is only borderline suitable for a physics forum - I just hope experts with a lot of experience ...
3
votes
2answers
301 views

Layman's method to sharpen a wire (STM-tip)

We use a platinum-irididum wire to fabricate our STM tips. And by "fabricate" I mean to cut it with really sharp pliers or scissors. Sometimes we get good tips but most of the time they are not usable ...
0
votes
1answer
89 views

How can I cheat an XRD sample (~10 mg) from a total 1g required? How can I use for the background.

How much can affect (in terms of hump) my X-ray diffraction pattern the "amorphous" glass or maybe someone can suggest me other material to compensate for the small amount of the sample. Note: my ...
5
votes
1answer
214 views

Real World measurements related to phonon dispersion [closed]

I hope no one objects to the style of this question. Let me explain my motives in asking the question first. Condensed matter physics is one of the most beautiful subjects around. But those who are ...
3
votes
2answers
279 views

Do I need to have an airtight container to siphon boiling water?

I'm attempting to siphon boiling water into another container for a school project. I have researched the physics of a siphon but I can't seem to make my boiling water siphon out of its initial pot. ...
0
votes
1answer
258 views

Repulsive Magnetic Hammering Experiment

I have been thinking about something thing... I want to attach four or any number of magnets with arms to an axle.. Blue dots be magnets. Its is not a wheel configuration, all arms can move ...
4
votes
1answer
2k views

Ways to create controlled small bubbles in water within plastic tubing

What is a practical way in an engineering or physics laboratory to create bubbles of a specified size in water within plastic tubing? The tubing is a few mm inner diameter. We'd like to make bubbles ...
1
vote
1answer
2k views

How do you calculate the equivalent absorbed radiation dose from activity, type of emission, and the energy of the emission?

I have a sample of U-238 of which my Geiger counter detects beta activity at 700 events per second. Based on the counter's efficiency of 98.6% for U-238, the activity would be about 710 becquerels, I ...
5
votes
2answers
466 views

statistics for photon counts in photomultiplier

It seems that a common statistical model for the count numbers of a photomultiplier is a Poisson distribution whose parameter $\lambda$ equals to the square-root of the number of counts.(e.g. ...
2
votes
1answer
369 views

Difference between Diamond anvil cell and Bridgman cell

In high pressure physics what is the difference between diamond anvil cells (DAC) and Bridgman cells? My understanding is that they are both forms of anvil cell but in the scientific literature I'm ...
0
votes
1answer
41 views

What is pulsed neutron diffraction?

I have tried a google search and checked my condensed matter books but I can't find out what pulsed neutron diffraction is and how it differs from inelastic neutron scattering.
3
votes
1answer
284 views

Rutherford's Gold Foil Experiment

Can anybody explain how Rutherford bombarded a 0.0004 cm thick gold foil? How did he put it in a photographic sheet? Wasn't the foil too thin to be held? How did he know that the atoms were deflected ...
5
votes
3answers
380 views

experimental technique for measuring temperature of an ant

I am taking a course on thermodynamics. I have a question from my text(halliday & resnick,physics-1). They asked me to measure temperature of an ant or an insect or a small body,like a small ...
3
votes
3answers
668 views

How to determine whether a large container is air-tight?

In constructing a kitchen-waste digester at home, I use a 50 Litre HDPE drum. The base of the drum is holed with a plug fitted to allow drainage when necessary. The top has two openings - one for ...
0
votes
1answer
685 views

Calculational method for determining surface tensions from photograph of menisci?

How can I get from a photograph of a liquid surface to a value for the surface tension.
3
votes
0answers
147 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 ...
0
votes
2answers
220 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 ...
1
vote
1answer
215 views

Calibrating an electronic temperature sensor based on power consumption

I'm working with an electronic temperature logger that is being affected by heat generated internally. How does one come up with a calibration equation to calculate a more accurate reading of ambient ...
5
votes
1answer
954 views

How the bond angle of a water molecule is measured?

How the angle of a water molecule is measured? The bond angle for water was first determined by vibrational and rotational analysis of its infrared absorption spectra. How is bond angle extracted?
5
votes
0answers
203 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 ...
6
votes
3answers
440 views

Vector Boson Fusion

I have been reading about the production mechanisms for the Higgs at the LHC. It is always mentioned that for Vector Boson Fusion, the initial quarks cause jets that are back to back and with a higher ...
0
votes
1answer
180 views

Increase the signal-to-noise ratio of photomultiplier

It is a GRE physics problem. A technique would most likely increase the signal- to-noise ratio of a photomultiplier tube is to operate the tube at a lower temperature operate the tube at higher ...
0
votes
2answers
176 views

Image contrast as function of exposure for a CCD detector

In a laser interferometry experiment, we project a pattern of interference fringes onto a CCD sensor. For best results, we want good contrast between the bright and dark fringes, and we carefully ...
2
votes
1answer
93 views

random triggers

I understand that a small proportion of events at the LHC that would not trigger on any deterministic trigger are saved on what might be called a random trigger, so that, amongst other uses, proposed ...
3
votes
1answer
197 views

What's an efficient way to produce graphite on TEM-Grids?

I am trying to produce graphene with few layers(<10) on a TEM-Grid. Until now I've been trying this with the scotch-tape-method with slight modifications. Unfortunately it requires a lot of time ...
5
votes
2answers
200 views

What has been measured at the Higgs experiment and what do we know now?

Explained at the level of a 5$^{\text {th}}$ semester physics student (i.e. pre QFT, but far beyond the level of a news article for non-physicists, which avoids all details and only deals in ...
0
votes
1answer
2k views

Franck-Hertz Experiment explanation

Can anyone explain to me how the Franck-Hertz experiment works? (in term of electric current and voltage changes) I am getting all confused. More specifically, why is an accelerating grid (or mesh ...
3
votes
1answer
1k views

Liquid nitrogen and liquid helium

In cryogenics, liquid nitrogen and liquid helium are often used as coolants. Other than their low boiling point of 77K and 4.2K respectively, what properties make them suitable as coolants? Are there ...
2
votes
1answer
229 views

Amount/flow rate of N2 needed to cool substrate

I'm trying to cool a substrate inside a vacuum chamber with liquid nitrogen. The substrate holder is a block of copper suspended from the top of the chamber via nylon screws (for thermal insulation). ...
0
votes
1answer
173 views

How was Dorsey able to measure speed of light with 3 significant digits?

How was Dorsey able to measure speed of light with 3 significant digits in the year of 1907?
4
votes
2answers
335 views

How does one get the value of acceleration of gravitation on earth accurately by experiment without electronic device?

How does one get the value of acceleration of gravitation on earth accurately to 5 significant digits by experiment without electronic device?