Curso de Métodos experimentales En la Física PCF UNAM Cuernavaca, Agosto 2008 cuarta semana Dr. Antonio M. Juárez Reyes, ICF UNAM

Curso de Métodos experimentalesEn la Física PCF UNAM

Cuernavaca, Agosto 2008

cuarta semana Dr. Antonio M. Juárez Reyes, ICF UNAM

Física Atómica, Molecular y óptica.


TEMARIO PARTE 1

I.- Instrumentos y conceptos básicos (Toño, 5 semanas)I.1.- Conceptos básicos de instrumentación

-Conceptos generales de seguridad en el laboratorio (eléctrica, de gases comprimidos, láseres y químicos. --El proceso de medida y asignación de incertidumbres.

I.2.- Instrumentos básicos2.1 sistemas de vacío. -Conductancia, velocidad de bombeo, viscosidad,-bombas: Rotatorias, de diafragma, difusoras, turbo, de sublimación,

ionicas. razón de compresión en bombas,- transductores de presión, pirani, Bayer Alpert, Baratrón, análisis de

gases residuales.2.2 Instrumentos básicos de electrónica:

-osciloscopios, generadores de señales, electrómetros,

2.3 Instrumentos avanzados-Amplificador Lock In-Integrador Boxcar-Monocromadores


I.3.- Conceptos generales de láseres y fuentes de luz:- Cavidades, ganancia y finesa-Etalones de Fabri Perot,-Quarter wave plates, half wave plates, Stokes parameters

-Optoacustic modulators-Dicroic mirrors

-Láseres pulsados de nitróngeno, Nd:YAG, pulsadores del tipo Q-Switch, láseres de diodo de cavidad extendida,

-Otras fuentes de luz: sincrotrónesy Free electron Lasers,

I.4.-Conceptos generales de diseño: herramientas de dibujo, herramientas de simulación de circuitos, criterios generales de diseño de piezas asociadas a instrumentación científica.El taller de electrónica y el taller de mecánica del ICF 1.5 Elección del proyectos semestrales de instrumentación


-Interferómetro de Fabri-Perot ( etalon)

A Fabry–Pérot interferometer (also called Fabry–Pérot resonator) is a linear optical resonator (or cavity) which consists of two highly reflecting mirrors (with some small transmittivity) and is often used as a high-resolution optical spectrometer. One exploits the fact that the transmission through such a resonator exhibits sharp resonances and is very small between those.

http://www.rp-photonics.com/interferometers.html

http://www.rp-photonics.com/optical_resonators.html

http://www.rp-photonics.com/cavities.html

http://www.rp-photonics.com/dielectric_mirrors.html



For optical spectrum analysis, the Fabry–Pérot interferometer is often made short enough to achieve a sufficiently large free spectral range; the bandwidth of the resonances is then the free spectral range divided by the finesse

Figure 2: Frequency-dependent transmission of a linear Fabry–Pérot cavity with mirror reflectivities of 90%.

http://www.rp-photonics.com/free_spectral_range.html

http://www.rp-photonics.com/bandwidth.html

http://www.rp-photonics.com/finesse.html



free spectral range; The free spectral range of an optical resonator (cavity) is the frequency spacing of its axial (Gaussian-shaped) resonator modes. It is therefore also called axial mode spacing. For an empty standing-wave resonator of length L, it can be calculated as

Bandwidth the width of the frequency range which can be transmitted by some element, e.g. an optical fiber

Finesse The finesse of an optical resonator (cavity) is defined as its free spectral range divided by the (full width

at half-maximum) bandwidth of its resonances.





http://www.rp-photonics.com/resonator_modes.html


http://www.rp-photonics.com/fibers.html








at half-maximum) bandwidth of its resonances.


If a fraction ρ of the circulating power is left after one round-trip (i.e., a fraction 1 − ρ of the power is lost), assuming that there is no incident field from outside the resonator, it can be shown that the finesse, F can be given by:









at half-maximum) bandwidth of its resonances.If a fraction ρ of the circulating power is left after one round-trip (i.e., a fraction 1 − ρ of the power is lost), assuming that there is no incident field from outside the resonator, it can be shown that the finesse, F can be given by:

A high finesse can be useful for optical spectrum analysis, because it allows the combination of a large free spectral range with a small resonator bandwidth. Therefore, a high spectral resolution in a wide spectral range is possible.










I.3.- Conceptos generales de láseres y fuentes de luz:- Cavidades, ganancia y finesa-Etalones de Fabri Perot,-Quarter wave plates, half wave plates, Stokes parameters-Spacial filters-Optical modulators-Dicroic mirrors

-Láseres pulsados de nitróngeno, Nd:YAG, pulsadores del tipo Q-Switch, láseres de diodo de cavidad extendida,

-Otras fuentes de luz: sincrotrónesy Free electron Lasers,


-Quarter wave plates, half wave plates, Stokes parameters

Optical waveplates (also called wave plates or retarder plates) are transparent plates with a carefully adjusted birefringence, which are mostly used for manipulating the polarization state of light beams.

A waveplate has a slow axis and a fast axis, both being perpendicular to the surface and the beam direction, and also to each other. The phase velocity of light is slightly higher for polarization along the fast axis.

This induces a Phase shift between orthogonal componentsOf light

http://www.rp-photonics.com/birefringence.html

http://www.rp-photonics.com/laser_beams.html

http://www.rp-photonics.com/phase_velocity.html

http://www.rp-photonics.com/polarization_of_laser_emission.html


-Quarter wave plates, half wave plates, Stokes parameters

A waveplate has a slow axis and a fast axis, both being perpendicular to the surface and the beam direction, and also to each other. The phase velocity of light is slightly higher for polarization along the fast axis.

This induces a Phase shift between orthogonal componentsOf light

The wave plate is characterized by the amount of relative phase Γ; that it imparts on the two components, which is related to the birefringence Δn and the thickness L of the crystal by the formula

http://www.rp-photonics.com/phase_velocity.html

http://www.rp-photonics.com/polarization_of_laser_emission.html


Exercise: Proof that, considering

Phase velocity Refractive index

Then: Is the phase shift induced by A biorrefringent material withA given ∆n

The most common types of waveplates are quarter-wave plates (λ/4 plates) and half-wave plates (λ/2 plates), where the difference of phase delays between the two linear polarization directions is π/2 or π, respectively


Ok, this is interesting, but, how does one use waveplates?

•When the plate is a half-wave plate(π -shift), then the polarization stays linear, but the polarization direction is rotated. For example, for an angle of 45° to the axes, the polarization direction is rotated by 90°.

•When the incident polarization is at an angle of 45° to the axes, a quarter-wave (π /2 shift)plate generates a state of circular polarization. (Other input polarizations lead to elliptical polarization states.) Conversely, ccircularly polarized light is converted into linearly polarized light. See mathematica ...


Ok, this is interesting, but, how does one use waveplates?

Waveplates are in a few words, the tools one uses to Manipulate the state of light.

Remember that a general polarization state is expressedIn terms of the Stokes Parameters.

See Stokes parameter .PDF …


-Optical modulators


An optical modulator is a device which can be used for manipulating a property of light – often of an optical beam, e.g. a laser beam.

Depending on which property of light is controlled, modulators are called intensity modulators, phase modulators, polarization modulators, spatial light modulators, etc.

A wide range of optical modulators are used in very different application areas, such as in optical fiber communications, displays, for active Q switching or mode locking of lasers, and in optical metrology.


http://www.rp-photonics.com/phase_modulators.html

http://www.rp-photonics.com/optical_fiber_communications.html

http://www.rp-photonics.com/q_switching.html

http://www.rp-photonics.com/active_mode_locking.html

http://www.rp-photonics.com/lasers.html

http://www.rp-photonics.com/optical_metrology.html


Types of Optical ModulatorsThere are very different kinds of optical modulators:Acousto-optic modulators are based on the acousto-optic effect. They are used for switching or continuously adjusting the amplitude of a laser beam, for shifting its optical frequency, or its spatial direction.Electro-optic modulators exploit the electro-optic effect in a Pockels cell. They can be used for modifying the polarization, phase or power of a beam, or for pulse picking in the context of ultrashort pulse amplifiers.Electroabsorption modulators are intensity modulators, used e.g. for data transmitters in optical fiber communications.Interferometric modulators, e.g. Mach–Zehnder modulators, are often realized in photonic integrated circuits for optical data transmission.

http://www.rp-photonics.com/acousto_optic_modulators.html

http://www.rp-photonics.com/electro_optic_modulators.html

http://www.rp-photonics.com/pockels_cells.html

http://www.rp-photonics.com/pulses.html

http://www.rp-photonics.com/ultrashort_pulses.html

http://www.rp-photonics.com/amplifiers.html

http://www.rp-photonics.com/electroabsorption_modulators.html

http://www.rp-photonics.com/optical_fiber_communications.html

http://www.rp-photonics.com/interferometers.html

http://www.rp-photonics.com/photonic_integrated_circuits.html

http://www.rp-photonics.com/optical_data_transmission.html


Acousto-optic Modulators

An acousto-optic modulator (AOM) is a device which can be used for controlling the power, frequency or spatial direction of a laser beam with an electrical drive signal. It is based on the acousto-optic effect, i.e. the modification of the refractive index by the oscillating mechanical pressure of a sound wave.


http://www.rp-photonics.com/refractive_index.html



The key element of an AOM is a transparent crystal (or piece of glass) through which the light propagates. A piezoelectric transducer attached to the crystal is used to excite a sound wave with a frequency of the order of 100 MHz. Light can then experience Bragg diffraction at the periodic refractive index grating generated by the sound wave; therefore, AOMs are sometimes called Bragg cells



The scattered beam has a slightly modified optical frequency (increased or decreased by the frequency of the sound wave) and a slightly different direction.

The frequency and direction of the scattered beam can be controlled via the frequency of the sound wave


Electro-optic modulators




An electro-optic modulator (EOM) (or electrooptic modulator) is a device which can be used for controlling the power, phase or polarization of a laser beam with an electrical control signal.

typically contains one or two Pockels cells, and possibly additional optical elements such as polarizers.

The principle of operation is based on the linear electro-optic effect (also called the Pockels effect), i.e., the modification of the refractive index of a nonlinear crystal by an electric field in proportion to the field strength.




http://www.rp-photonics.com/electro_optic_effect.html

http://www.rp-photonics.com/pockels_effect.html


http://www.rp-photonics.com/nonlinear_crystal_materials.html



An electro-optic modulator (EOM) (or electrooptic modulator) is a device which can be used for controlling the power, phase or polarization of a laser beam with an electrical control signal.

typically contains one or two Pockels cells, and possibly additional optical elements such as polarizers.

The principle of operation is based on the linear electro-optic effect (also called the Pockels effect), i.e., the modification of the refractive index of a nonlinear crystal by an electric field in proportion to the field strength.










A Pockels cell is a device consisting of an electro-optic crystal (with some electrodes attached to it) through which a light beam can propagate. The phase delay in the crystal (→ Pockels effect) can be modulated by applying a variable electric voltage.

Only non-centrosymmetric materials (mostly crystals) exhibit the linear electro-optic effect, also called the Pockels effect, where the refractive index change is proportional to the electric field strength







Electro-optic modulators The Pockels effect (first described in 1906 by the German physicist Friedrich Pockels) is the linear electro-optic effect, where the refractive index of a medium is modified in proportion to the applied electric field strength.

This effect can occur only in non-centrosymmetric materials. The most important materials of this type are crystal materials such as lithium niobate (LiNbO3), lithium tantalate (LiTaO3), potassium di-deuterium phosphate (KD*P), β-barium borate (BBO), potassium titanium oxide phosphate (KTP), and compound semiconductors such as gallium arsenide (GaAs) and indium phosphide (InP).






Other optical modulators

An electroabsorption modulator (or electro-absorption modulator) is a semiconductor device which can be used for controlling (modulating) the intensity of a laser beam via an electric voltage

Its principle of operation is based on the Franz–Keldysh effect [1, 2], i.e., a change in the absorption spectrum caused by an applied electric field, which changes the bandgap energy

[1]L. V. Keldysh, “Behaviour of non-metallic crystals in strong electric fields”, J. Exp. Theor. Phys. (USSR) 33, 994 (1957); translation: Sov. Phys. JETP 6, 763 (1958)



Electro-optic modulators The Pockels effect (first described in 1906 by the German physicist Friedrich Pockels) is the linear electro-optic effect, where the refractive index of a medium is modified in proportion to the applied electric field strength.

This effect can occur only in non-centrosymmetric materials. The most important materials of this type are crystal materials such as lithium niobate (LiNbO3), lithium tantalate (LiTaO3), potassium di-deuterium phosphate (KD*P), β-barium borate (BBO), potassium titanium oxide phosphate (KTP), and compound semiconductors such as gallium arsenide (GaAs) and indium phosphide (InP).







Mathematically, the Pockels effect is best described via the induced deformation of the index ellipsoid, which is defined by

in a Cartesian coordinate system. An electric field can now change the coefficients according to




Figure 1: Pockels cells of various types.



-Dicroic mirrors


-Dicroic mirrors

Definition: mirrors with significantly different reflection or transmission properties at two different wavelengths

http://www.rp-photonics.com/glossary.html


-Dicroic mirrorsDefinition: mirrors with significantly different reflection or transmission properties at two different wavelengths

Figure 1: Reflectivity spectrum of a dichroic mirror coating, designed for high transmission (low reflectivity) around 808 nm and high reflectivity at 1064 nm.

http://www.rp-photonics.com/glossary.html


-Dicroic mirrors

A dielectric mirror consists of multiple thin layers of (usually two) different transparent optical materials (→ dielectric coatings, thin-film coatings, interference coatings).

Dielectric coatings, also called thin-film coatings or interference coatings, consist of thin (typically sub-micron) layers of transparent dielectric materials, which are deposited on a substrate. Their function is essentially to modify the reflective properties of the surface by exploiting the interference of reflections from multiple optical interfaces.

http://www.rp-photonics.com/dielectric_coatings.html

http://www.rp-photonics.com/interference.html


-Dicroic mirrors

Even if the Fresnel reflection coefficient from a single interface between two materials is small (due to a small difference in refractive indices), the reflections from many interfaces can (in a certain wavelength range) constructively interfere to result in a very high overall reflectivity of the device.

he simplest and most common design is that of a Bragg mirror, where all optical layer thickness values are just one-quarter of the design wavelength.


http://www.rp-photonics.com/interference.html

http://www.rp-photonics.com/bragg_mirrors.html


-Dicroic mirrors

A Bragg mirror (also called distributed Bragg reflector) is a structure which consists of an alternating sequence of layers of two different optical materials.

The most frequently used design is that of a quarter-wave mirror, where each optical layer thickness corresponding to one quarter of the wavelength for which the mirror is designed.

http://www.rp-photonics.com/quarter_wave_mirrors.html


-Dicroic mirrors

The principle of operation can be understood as follows. Each interface between the two materials contributes a Fresnel reflection. For the design wavelength, the optical path length difference between reflections from subsequent interfaces is half the wavelength; in addition, the reflection coefficients for the interfaces have alternating signs.


-Dicroic mirrors

Figure 1: Field penetration into a Bragg mirror.

The intensity distribution inside the dielectric mirror can be rather complex!


Figure 3: Field penetration into the Bragg mirror as a function of wavelength. The colors indicate the optical intensity inside the mirror.

More complex separations cangive rise to mirrors whichReflect over a wide band of frequencies


-Zone Plates


-Zone Plates

A zone plate is a device which focuses light using diffraction instead of refraction.

They were devised by by Augustin-Jean Fresnel and are also called Fresnel zone plates For this reason

A zone plate consists of a set of radially symmetric rings, known as Fresnel zones, which alternate between opaque and transparent. Light hitting the zone plate will diffract around the opaque zones. The zones can be spaced so that the diffracted light constructively interferes at the desired focus,

http://en.wikipedia.org/wiki/Focus_%28optics%29

http://en.wikipedia.org/wiki/Diffraction

http://en.wikipedia.org/wiki/Refraction

http://en.wikipedia.org/wiki/Augustin-Jean_Fresnel

http://en.wikipedia.org/wiki/Symmetric

http://en.wikipedia.org/wiki/Fresnel_zone

http://en.wikipedia.org/wiki/Opacity_%28optics%29

http://en.wikipedia.org/wiki/Transparency_%28optics%29

http://en.wikipedia.org/wiki/Diffraction

http://en.wikipedia.org/wiki/Interference


A zone plate consists of a set of radially symmetric rings, known as Fresnel zones, which alternate between opaque and transparent. Light hitting the zone plate will diffract around the opaque zones. The zones can be spaced so that the diffracted light constructively interferes at the desired focus,

-Zone Plates

http://en.wikipedia.org/wiki/Symmetric

http://en.wikipedia.org/wiki/Fresnel_zone

http://en.wikipedia.org/wiki/Opacity_%28optics%29

Fuentes de luz UV.

1.- Introducción

2.- Principios básicos de radiación sincrotrónica.

2.1 Un poco de historia.2.2 Propiedades de la radiación sincrotrónica2.3 Aplicaciones y usos.

3.- Fotoionización de hidrógeno molecular, H2.

3.1 Ortho y para-hydrógeno: O, de como la estadística Fermi-Dirac nos brinda dos tipos de moléculas de H2.3.2 Como obtener para-H2 a partir de H2 normal.3.3. Medición de niveles rotacionales en para-H2 usando radiación sincrotrónica.

1. Introducción1. Introducción

* La investigación basica inicia como un ejercicio de curiosidad… e inevitablemente se traduce en

aplicaciones en campos diversos y distintos del original.

El desarrollo de fuentes de luz , como el laser y la radiacion sincrotrónica (de la que hablaremos en esta plática) son ejemplos de lo anterior.

1. Introducción.

Que cosa es, antes que nada, la radiacion sincrotrónica

Brevemente, se puede definir como la radiación electromagnética emitida por un electrón que se acelera mientras viaja a velocidades cercanas a la velocidad de

la luz, C .

Esta radiación va de el infrarrojo a los rayos X (pasando por el ultravioleta) , es continua en frecuencia y muy intensa.

2.- 2.- Principios básicos de radiación sincrotrónicaPrincipios básicos de radiación sincrotrónica..2.1 Un poco de historia...2.1 Un poco de historia...

El fenomeno de difracción de Bragg…..

...Así como el descubrimiento de

la doble hélice de ADN.


A pesar de esa importancia, las fuentes de luz en el utravioleta y los rayos X estuvieron limitadas por más de medio siglo a fuentes relativamente débiles, y que emitían luz en unas cuantas frecuencias...

Aparato de rayos X (esquema)


El interés en colisiones a altas energías en la década de los 50´s llevo a los físicos a desarrollar aceleradores que permitieran realizar colisiones frontales entre partículas a velocidades enormes ( y observar los productos resultantes)

Las partículas se hacen girar en órbitas circulares opuestas, y se hacen colisionar en lugares específicos del tunel.

Tunel en CERN


Luz emanando del famoso acelerador en laboratoriosde la General Electrics.

En 1947 (mientras se pretendia hacer otra cosa), técnicos y cientificos de la General electrics descrubrieron la radiación sincrotrón.

Esto fue un tanto accidental puesto que la cámara de vacío del acelerador era de vidrio.

A la radiación descubierta se le llamo inicialmente Radiación de Schwinger


Cuando fue evidente que los usos de la radiación sincrotrón merecian un acelerador por derecho propio, aceleradores mas eficientes fueron desarrollados con el objetivo específico de aprovechar al máximo las ventajas de la radiación sincrotrónica.

(Segunda generación)

Laboratorio de Daresbury

Laboratorio Bessy, Berlin.


Estas fuentes de segunda generación producen luz sincrotrón acelerando electrones con imanes de alta intensidad de campo magnético.


Avances ulteriores en el diseño de imanes arreglados en forma periódicos, así como de óptica optimizada para su uso en el ultravioleta y los rayos X llevaron al desarrollo de fuentes cada vez mas brillantes y especializadas, que constituyen las fuentes de “tercera generación”.

Estas fuentes se caracterizan por el uso de “elementos de inserción”


La periodicidad del campo magnético se arregla de tal manera que los electrones realicen una oscilacion sinusoidal. En cada punto de inflexión de esta trayectoria ondulante los electrones emiten radiación

Si el período del los imanes se elige adecuadamente, se conseguirá interferencia constructiva. Esto su vez lograra que se multiplique en órdenes de magnitud, la intensidad de a luz producida.


Los sincrotrones que basan su operacion en el uso de elementos de inserción se les denomina de “tercera generación”

Sincrotrón Elettra, Trieste,ItaliaALS, Berkeley, vista de una estación experimental


Cuarta generación… Fuentes de radiación sincrotrón por electrones libres.

Aunque los laseres de electrones libres ya existen, las fuentes de cuarta generacion planean extender sus rangos espectrales al UV y los rayos X (4GLS)

2.- 2.- Principios básicos de radiación sincrotrónicaPrincipios básicos de radiación sincrotrónica..2.2 Propiedades de la radiación sincrotrónica2.2 Propiedades de la radiación sincrotrónica

2.2 Propiedades de la radiación sincrotrónica

Un electron, de carga e, que es acelarado con aceleracion a, radia energia electromagnética en distintas direcciones. En particular, la potencia por unidad de angulo sólido esta dada por la siguiente expresion:

ΘdΩdP sincε16π

ar 23

o

2

22

Electrodinámica no-relativista


cos

sintan

Donde Θ es el ángulo de un observador en reposo y Θ ´es el angulo medido en el sistema de referencia que se mueve.

Ademas: =v/c y =1/(1-v2/c2)1/2

Para apreciar de manera fácil que pasa con la radiación emitida por un electron relativista, tal como es vista por un observador en reposo, basta observar que, en el limite relativista, 1, >>1

En este limite, Θ queda acotado por el valor maximo 1/


Comparación de los patrones de radiación electromagnética entre (a) un electron que se observa en el mismo sistema de referencia y (b) un electrón que se mueve a velocidades relativistas, desde un sistema de referencia fijo en el laboratorio.


2.2.2. Composición espectral de la radiación sincrotrónica. Por que es continua la luz sincrotrón?

Debido a que la radiación es emitida en un cono de luz, un observador fijo vería, conforme el electrón gira en su órbita, un pulso de luz solo cuando el electrón pasara frente al observador, como se muestra en la figura 2.


2.2.2. Composición espectral de la radiación sincrotrónica.

322

cRt

Un argumento físico sencillo para explicar la presencia de un continuo de colores en la radiación sincrotron es, notando que el tiempo de tránsito del electrón para un observador fijo es:

Recordando que: Et=/2

Entonces:R

cE

32


Free Electron Lasers

Definition: laser devices where light amplification occurs by interaction with fast electrons in an undulator

Figure 1: Setup of an undulator, as used in a free electron laser. The periodically varying magnetic field forces the electron beam (blue) on a slightly oscillatory path, which leads to emission of radiation.




Figure 1: Setup of an undulator, as used in a free electron laser. The periodically varying magnetic field forces the electron beam (blue) on a slightly oscillatory path, which leads to emission of radiation.




A free electron laser is a relatively exotic type of laser where the optical amplification is achieved in an undulator, fed with high energy (relativistic) electrons from an electron accelerator.


uch devices have been demonstrated with emission wavelengths reaching from the terahertz region via the far- and near-infrared, the visible and ultraviolet range to the X-ray region

K.-J. Kim and A. Sessler, “Free-electron lasers: present status and future prospects”, Science 250, 88 (1990)

G. R. Neil and L. Merminga, “Technical approaches for high-average-power free-electron lasers”, Rev. Mod. Phys. 74, 685 (2002)

W. Ackermann et al., “Operation of a free-electron laser from the extreme ultraviolet to the water window”, Nat. Photonics 1, 336 (2007)


The underlying principle of the intense pulses from the X-ray laser lies in the principle of Self-Amplified Stimulated-Emission which leads to the microbunching of the electrons.

Self-Amplified Spontaneous (or Stimulated) Emission (SASE) is a process within a Free electron laser (FEL) by which a laser beam is created by the high-energy electron beam.


The underlying principle of the intense pulses from the X-ray laser lies in the principle of Self-Amplified Stimulated-Emission which leads to the microbunching of the electrons.

Self-Amplified Spontaneous (or Stimulated) Emission (SASE) is the process responsible of the coherence and laser-like properties present in a Free electron Laser



El ancho de banda proporcionado por la radiación (del infrarrojo a los rayos X duros, e incluso gamma, no puede obtenerse de ninguna otra fuente hecha por el hombre… de ahí su importancia práctica …

2.- 2.- Principios básicos de radiación sincrotrónicaPrincipios básicos de radiación sincrotrónica..2.3 Algunas aplicaciones de la radiación sincrotroón2.3 Algunas aplicaciones de la radiación sincrotroón

2.3 Aplicaciones

2.3 lista breve de algunos usos y aplicaciones de radiación sincrotrónica.

1.- Caracterizacion de esfuerzos de tension y esfuerzo de materiales. Por ejemplo, en alas de aviones (airbus, en sus esudios de aleaciones para sus nuevos modelos)

Estudios de difracción de rayos X de las juntas de componentes críticas. (valido par un sinfín de materiales.. Acero, concreto…


2.- Estudio de la estructura por difracción de rayos X, de proteínas de importancia biológica, como la hemoglobina y la insulina.

3.- Estudio de fotoionización, disociación, recombinación de moléculas y radicales libres de importancia atmosférica ( O2, O3, SO2, NO, N2O, NO2) .


Litografía con ultravioleta para desarrollo de microcomponentes, memorias magneticas de alta densidad, estudio de nanoestructuras, orientacion de cristales líquidos… la lista es tan grande como uno quiera.

Documents

Curso de Métodos experimentales En la Física PCF UNAM Cuernavaca, Agosto 2008 cuarta semana Dr. Antonio M. Juárez Reyes, ICF UNAM