of watts at frequencies above 200 GHz. Gyrotrons look promising for plasma diagnostics and various pump-probe spectroscopy methods. For instance, gyrotrons are already successfully used for dynamic nuclear polarization (DNP) in nuclear magnetic resonance (NMR) spectroscopy (-- removed HTML --) (-- removed HTML --) 1–5 (-- removed HTML --) (-- removed HTML --) where significant sensitivity enhancement was observed with sub-terahertz irradiation power of 1–10 W. (-- removed HTML --) (-- removed
at a low pressure to a carrier gas such as oxygen, argon or nitrogen. At such high frequencies, electrons due to their small masses, can accelerate toward the higher energy-levels, however, this is not the case for the heavier ions, therefore, the temperature of electrons increases, but for heavier ions it will remain low, and so this is a non-isothermal plasma. In the microwave plasmas, the electrons with their high energy levels are responsible for collision with the gas molecules to dissociate
PET Scan Up until the 1970’s, physicians had access to several different imaging systems such as CT (Computed Tomography) and MRI (Magnetic Resonance Imaging), but these types of imaging only allowed physicians to see the internal structures of the body, not how they functioned. With the advent of PET, the physicians are now able to see and record these functions. PET stands for Positron emission tomography. PET is a medical diagnostic imaging procedure that uses nuclear medicine in a noninvasive
--) The electron Bernstein mode is one of the fundamental modes of plasma which was first studied by Bernstein in 1958. (-- removed HTML --) (-- removed HTML --) 19 (-- removed HTML --) (-- removed HTML --) This is a perpendicularly propagating electrostatic mode investigated in hot magnetized uniform plasma and can propagate towards the core of the plasma without encountering density cut-off and interacts strongly with electrons in the vicinity of the Doppler shifted electron cyclotron resonance
nuclear medicine in their lifetime. To understand what a radioactive isotope is a basic understanding of the atom is necessary. Atoms are comprised of three subatomic particles : protons, neutrons and electrons. Protons and neutrons bind together to form the nucleus of the atom, while the electrons surround and orbit the
because of their characteristic nature of producing radiation and their energies. Isotopes are used in various areas like industries, agriculture, medical field and research centers. They are decayed by emission of energy in the form of alpha, beta (electron) beta plus (positron) and gamma rays. (1) Types of radiation Alpha particles cannot be used for measurement from outside the body because they are such low penetrating power. A sheet of paper stops alpha particles. Beta particles have a modest penetrating
frequencies employed range from about 100 kHz to 40 MHz at gas pressures between 50 mtorr to 5 torr. Under these conditions, electron and positive-ion densities number between lo9 and 101*/cm3, and average electron energies range from 1 to 10 eV. This energetic discharge environment is sufficient to decompose gas molecules into a variety of component species, such as electrons, ions, atoms, and molecules in ground and excited states, free radicals, etc. The net effect of the interactions among these
Shortly after Roentgen discovered x-rays in 1895, studies were done observing “the transfer of energy from the beam of radiation to the biologic system and the … effects of this interaction”, becoming the basic principles of radiation oncology (Frank et al, 2012, p. 469). As people were experimenting with the new founded x-ray, scientists began to notice the immediate and delayed effects of radiation (Frank et al, 2012, p. 469). Two of the main effects that were noticed were “epilation (loss of hair)
Física da Radiação, 1º semestre, IST, 2010/2011 1 Radiopharmacology Radiopharmacology Diogo Ferreira, diogo.cunha.ferreira123@gmail.com MSc student in Biomedical Engineering, Instituto Superior Técnico, student no58548 Abstract Nuclear Medicine is the branch of medicine concerned with the use of radio-nuclides in the study and the diagnosis of diseases, eg. the assessment of organ function, detection and treatment of some diseases or monitoring of treatment’s effects. It provides physiological
Fullerene was first recorded in a Japanese article, Kagaku, written by Eiji Osawa in 1970 which stated the prediction on the existence of C60 compound [1]. In the following year, a conjecture on the stability of C60 was established by Osawa and Yoshida where the aromatic characteristic of C60 was described further. The stability was further better-explained when the Hückel’s calculation method was applied and introduced to the icosahedron structure of C60 by Bochvar and Gal’pern [2]. The prediction