Cross section Definition and 315 Threads

New here, sorry if I'm in the wrong place or unclear, etc. I've been looking at torsion on solid plates and the torsion constant. I was wondering how to handle the torsion constant on a plate of changing cross section (e.g. there are holes drilled in it, changing the area of the cross section...

Homework Statement DT fusion produces 14.1 MeV neutrons. A diagnostic for a total fusion yield is the Cu-63( n, 2n)Cu-62 reaction. A) what is the threshold for this reaction? Cu-63 also undergoes a radiative capture reaction yielding Cu-64. This reaction has a thermal cross section of 4.5b...

Hi everyone? What is Born cross section? And what is the relation between it and observed cross section? Thank you.

Homework Statement Why don't hydrogen cross-sections exhibit resonances? Homework Equations N/A The Attempt at a Solution I was thinking it had something to do with the spin, the fact that is has only one electron, or elastic scattering, but I can't seem to wrap my brain around...

differential cross section of coulomb scattering can be expressed as a form factor times Rutherford one, we model the charge we used spherically symmetric charge density, if we replace this point charge with other distribution like Gaussian , what is the difference between these two models, is...

Homework Statement A medium carbon annealed steel rod has a rectangular cross section and must cope with a tension of 3 tonnes. The thickness of the rod is 15mm. Calculate the size of the cross section. Tension limit = 3 tonnes Thickness = 15mm Cross Section = ? Homework Equations...

Homework Statement Consider a cylindrical tank filled with water with 2.5-m depth. The water emerges from a small hole at the center of the bottom, as shown in the figure. The diameter of the hole is 1 mm. The cross-section area of the vertical water stream decreases as it falls. Find the...

Homework Statement Hi. I'm trying to calculate the cross section for this process: where \phi is a massive neutral scalar, N is a massive Majorana neutrino and \nuL is the normal SM neutrino. Homework Equations N/A The Attempt at a Solution Apparently the answer should be something like...

Homework Statement In an experiment carried out with a beam of thermal neutrons it is found that on traversing a 2mm thick foil of 197Au, some 70% of the neutrons are removed. What is the total thermal neutron cross-section for this isotope of gold? (Density of gold: 19300 kg m-3) Homework...

Why is it that the differential cross section for processes like Inverse Muon Decay (IMD) are always given in the CM frame? Every paper I have seen that discusses Inverse Muon Decay gives the differential cross section in CM frame. Is it very hard to calculate the differential cross section in...

What is the neutron scattering Differential Cross section .. simple definition? ... Thanks

I do not understand the interpretation of the http://hyperphysics.phy-astr.gsu.edu/hbase/rutsca.html" . To me, that equation says: (1) for a given θ, the proportion of particles exiting at θ does NOT depend on mass or charge; (2) if you integrated over all possible scattering angles, you...

I am replacing an exisitng solid rod with a new rod with a rod made from a different material and a different cross section. The new material has a MOE that varies with skin depth which is making it hard for me to develop an expression for stiffness (EI). The new rod has a hollow...

Hallo Physics Forum, this is my first post, so please be gentle to me :). I am currently studying the relativistic photoionization process, and especially its differential cross section. Let us assume that we have a highly energetic, unpolarized photon beam traveling on the z-axis and...

Rhodium has been measured and the following values have been obtained for the resonance parameters of a well-isolated resonance Eo=1.26 ev , σo=5000 b , Γ = 0.156 ev , σs=5.5 b , Is there anyone can help me HOW to calculate the thermal absorption cross section ? I'm disparate I don't know how to...

Homework Statement The base region of a solid is bounded by y=x, y=(x-1)^2, and x = 1. The cross sections are semicircles perpendicular to the x-axis. Write a riemann sum and definite integral. Homework Equations The Attempt at a Solution First, I wrote down the formula...

Homework Statement Red and green laser (wavelength of 650 nm and 532 nm respectively) are directed towards each other at 20 degrees. Each laser has 5 mW power, with diameter of 1mm. Assuming the intensity of the beams are decreased by 10% each after the 'collision', estimate the upper...

I'm currently starting a large comp-astro project, and trying to understand a bit of the background about heading of Hydrogen and Helium IGM clouds I am a bit confused about the the actual heating process. From the standard photoelectric effect, frequency has to pass a certain frequency (or...

Homework Statement Using conductivity constant (q=1.45*10^6mA) deduce the cross-Sectional area of the wire from the slope of the Data found in the graph. Voltage was kept constant 1.00 volts The wires are each 1m long After graphing the data the Current(mA) # of parralel lines 121.4...

Recently, I had lab. In the lab we took different objects and measured their strain. One object had a varying cross section. The data for strain was recorded. Right now, I'm trying to make a stress strain graph, but the problem is my equation for stress. I don't know how i can take my moment of...

from what I know: cross section in particles physics can be seen as throwing random darts on ballons on a wall, ie the wall is stationary. but if I want to work out the cross section of two laser beams at certain angles, the analogy above wouldn't hold would it? Since photons can never to...

In particle physics, what is a differential cross section? I think I understand what a cross section is, but I can't find any information on what a differential cross section is. I don't see how a cross section could be differentiated.

hi i am currently looking for a derivation of the differential cross section, that is not an abuse of mathematics, cause all derivation i found use differentials that are treated like fractions and so on? greetings Gavroy

So I have been reading about the cross section of neutron capture and have been reading about how the cross section for neutrons in a given material depends on neutron energy, the most important factor obviously. But I have not seen as much information on how, for a neutron of a given thermal...

Homework Statement The Femur bone in the human leg has a minimum effective cross section of about 3.0 cm2 How much compressible force can it withstand before breaking Homework Equations Compressive Strength (bone)(N/m2) = 170 x 106 P = F/A The Attempt at a Solution Not sure what a...

Homework Statement base of a solid is bounded by y=\sqrt{x}, the x-axis, and x=9. each cross-section perpendicular to the x-axis is a semi-circle. find the volume of the solid Homework Equations The Attempt at a Solution I found the answer to be 81\pi/16 by the following steps...

Hi. I am looking for some help calculating a cross section to derive the frequency of reaction in the early universe. The reaction taking place is: \nu_e + n \longleftrightarrow p + e^- After some calculation I came here: n_\nu \langle \sigma v \rangle = \frac {(2\pi)} {8 m^2}...

hi guys, I was wondering what is the equation of cross section between fuselage and wing of the below airplanes:antonov 140 , B-707 , cessna-210 , cessna citation. Can anyone help?a book or a refrence or whatever you have

hi guys, I was wondering what is the equation of cross section between fuselage and wing of the below airplanes:antonov 140 , B-707 , cessna-210 , cessna citation. Can anyone help?a book or a refrence or whatever you have

Homework Statement What target thickness d is necessary to ensure that 1 % of all protons with a laboratory momentum of 10 GeV interact in a C12 – target? Homework Equations I have found af formula that states cross section = N_Reac/(N_beam * N_A * ro*d/M) Where N_Reac is the...

Hi everybody, I have a experimental question. In cross-section calculation of production of particles (say D), one counts the number of produced D. To selection the D one has to apply some kinematic cuts. If cuts are tight, number of D will be less and if cuts are loose, number of D will be...

Hey, The hard cross-section of a 2 to 2 inelastic scattering goes as 1/E^2, where E is the center of mass energy. However, the cross-section in proton proton collisions increases with energy. My question is; does anybody have a good explanation for this and/or a good reference where I can...

Homework Statement Hi, I'm currently carrying out a computing project on Resonant Scattering and when I have identified a resonant state, I need to examine whether it has a "particular signature". However, I'm not really sure what this means... Homework Equations The differential...

Homework Statement I do need to calculate the mean free path for an ion with a radius of 9 x 10‐8 cm in pressures of 10‐8 Torr, 10‐6 Torr, 10‐4 Torr and 10‐2 Torr Homework Equations There are different equations I found but the most one is λ= 1/Nσ N gas number density which I do not...

Homework Statement Calculate the differential cross section for A+B---> C+D with an invariant matrix element Homework Equations See attachment The Attempt at a Solution I have no idea how to even begin this problem. The course I am taking is an undergraduate course in intermediate modern...

Homework Statement A cmedium carbon steel rod has a rectangular cross section and must cope with a tension of 29 430 Newtons . The thickness of the rod is 15 mm calculate the siz of the cross section? Homework Equations A=P/Ok [b]3. The Attempt at a Solution [/b O = UTS = 750...

hi how to calculate the traces of product of Dirac matrices in QED. i want caculate crossection of process scattering in QED. a program to calculate it

Does anyone know how SolidWorks calculates the stresses for this simulation. Can anyone give me an idea, is it second moment of area? y/r = m/i? Thanks Richard.

Photon interaction cross section? What?!? Hey guys-- I'm practicing for the GRE, and I came across a question that has stuff that's not even in my textbook! I haven't found much from googling either. Here is the question: My instinct was to guess (C) because graphs I had seen of the...

Homework Statement a) Define the differential cross section \frac{d\sigma}{d\Omega} in “experimental” terms, i.e., in terms of the number of scattered and incident particle. b) Show that for a situation in which there is a scattered wave f^+\left(\theta\right)\frac{e^{ikr}}{r} asymptotically...

design a tension member w/ cross section... Homework Statement You are to design a tension member (square rod) with a cross section to carry a mass of 575 000 kg with a safety factor of 2 against yield and a safety factor of 3 against static fracture (overload). a) What is the design...

Hi, Has anyone tried using the HFSS software to get the extinction cross section of a particle? I've been told that the extinction cross section of a particle is the imaginary part of the radar cross section in forward direction, so I did exactly what the RCS tutorial from HFSS did, except...

I wanted information on the 18F production rates of 18O(p,n)18F compared to 20Ne(d,alpha)18F. I found a 1979 graph that showed some nice curves between 2.3 and 22 MeV but I wanted to see what things looked like between 1 MeV and 2.5 MeV. So I went here...

Homework Statement the prism is made from glass, and its cross section is an equilateral triangle. the indices of refraction for the red and violet light are 1.662 and 1.698, respectively. the angle of incidence for both the red and violet light is 60 degrees. find the angles of refraction at...

Homework Statement I need to calculate the differential cross section in order of Mandelstam variable t, instead of the angle \theta. My problem is with the change of variable not the amplitude of the process. I'm getting a global minus sign which can only be wrong. It seems I'm making a very...

It strikes me that this may well be fairly easy, but i can't quite get my head round the correct way to lay this problem out (at least in a mathematical sense). If you are considering a neutron flux onto a fully understood material, and you also know the neutron interaction cross section of...

I need help with my beam structure in abaqus. The beams I need to model are hollow and elliptical. This is not included in abaqus' library or profiles. So I want to make a Meshed beam cross section as described in the manual. However, the manual is quite difficult to understand. Can someone...

Hey guys I am new here i was wondering if anyone can help me understand this problem better Homework Statement The base of a certain solid is the circle x^2 + y^2 = 9. Cross sections of the solid with planes perpendicular to the y-axis are semicircles with their diameter in the base of the...

What's the relation for the Compton cross section? I remember it going as 1/(1-cos(theta)) but can't remember the rest. I searched for a derivation but can't find one at the moment.

hi We all know when velocity of fluid increases then cross section decreases for same mass flow rate and this can be well seen at water flowing from a height as in waterfalls. But why this doesn't happen when water flows down through a vertical held pipe of constant cross section. Well you may...