Show the full calculation steps to justify why the single-photon energy is 511 keV during the mutual annihilation of a positron (e+ ) and an electron (e- ) in the human body. This is the basic principle of PET.

You are asked to design a spectral filter that practically removes 99.0% of the low energy photons in an X-ray beam. Such photons contribute to the patient dose without contributing to the image and are defined as no more than 1% of these photons making it to the other side of the patient. Assume a patient can be modelled as a 20cm thick homogenous object with linear attenuation coefficients as shown below in Table 1. What is the thickness of the filter needed to eliminate all the energies which satisfy the above requirement? Filter linear attenuation properties are given below in Table 2. Table 1: Linear attenuation coefficients vs. energy of patient equivalent material Energy [keV] Habject (mm| 20 0.02601 30 0.02407 40 0.02303 50 60 0.02151 0.02013 Table 2: Linear attenuation coefficients vs. energy of filter material 60 0.06684 20 Energy (keV] Hrter (mm 30 40 50 70 0.1225 0.1067 0.0872 0.07541 0.06327

A photon produces a proton−antiproton pair according to the reaction γ → p +P- . What is the minimum possible frequency of the photon? What is its wavelength?

A single neutron confined inside a nucleus has a minimum kinetic energy Kmin consider it to be a cube of volume a³. Give your answer to 2 significant figures in units of fm. (fm femtometers = 10 15 m) 20 MeV. Find the size a of the nucleus if we Formulas.pdf (Click here-->)

The purpose of this problem is to show in three ways thatthe binding energy of the electron in a hydrogen atom isnegligible compared with the masses of the proton andelectron. (a) Calculate the mass equivalent in u of the 13.6-eVbinding energy of an electron in a hydrogen atom, andcompare this with the mass of the hydrogen atom obtainedfrom list given. (b) Subtract the mass of the proton given from the mass of the hydrogen atom given . You will find the difference is equal to theelectron’s mass to three digits, implying the binding energy issmall in comparison. (c) Take the ratio of the binding energyof the electron (13.6 eV) to the energy equivalent of theelectron’s mass (0.511 MeV). (d) Discuss how your answersconfirm the stated purpose of this problem.

A neutron is scattered through an angle of 60 degree in the C.M syste m in collision with Carbon.Find the fractional loss the energy of the neutrons.Also calculate the maximum fractional energy loss in this case?Use I given

An electron and a positron collide head on, annihilate, andcreate two 0.85-MeV photons traveling in opposite directions. What were the initial kinetic energies of electronand positron?

According to the article Alien Antimatter Crashes into Earth 2 : More than 60 years ago, future Nobel laureate Sheldon Glashow predicted that if an collided with an antineutrino the antimatter answer to the nearly massless neutrino electron, it could produce a cascade of other particles. The "Glashow resonance - phenomenon is hard to detect, in large part because the antineutrino needs about 1,000 %3D times more energy than what's produced in the most powerful colliders on Earth. Let's compare this event to an ordinary baseball with a mass of 146 g. Please use three significant figures in your calculations.

A photon produces a proton-antiproton pair according to the reaction y → p + p. What is the minimum possible fre- quency of the photon? What is its wavelength?

The Big Bang theory  states that the beginningof the universe was accompanied by a huge burst ofphotons. Those photons are still present today and make upthe so-called cosmic microwave background radiation.The universe radiates like a blackbody with a temperaturetoday of about 2.7 K. Calculate the peak wavelength of thisradiation