
==============================  multilayer  ====================================

 Mlayer is a widget based graphical interface to calculate multilayer 
 reflectivities as a function of either the photon energy or incident angle.

 The multilayer code uses python code from shadow4 project:
 https://github.com/srio/shadow4/tree/master/shadow4/physical_models/mlayer
 that evolved from the fortran code witten by J.H. Underwood at CXRO and 
 is part of the SHADOW package. 

 Schematic representation of the multilayer:

               vacuum
    |------------------------------|  \
    |          odd (1)             |  |
    |------------------------------|  | BILAYER # n_bilayers
    |          even (2)            |  |
    |------------------------------|  /
    |          .                   |
    |          .                   |
    |          .                   |
    |------------------------------|  \
    |          odd (2n - 1)        |  |
    |------------------------------|  | BILAYER # 1
    |          even (2n)           |  |
    |------------------------------|  /
    |                              |
    |///////// substrate //////////|
    |                              |

material: Three options are available:
	a) Element(formula): calculation for a single element.
	b) Compounds(formula):  calculation for a compound. The user
		defines the compound formula.
		The syntaxis is the following: string with the chemical
		formula of the compound.
		Examples:
		H20
		SiO2
	c) Compounds(by name) from the NIST list of compounds:

A-150 Tissue-Equivalent Plastic
Acetone
Acetylene
Adenine
Adipose Tissue (ICRP)
Air, Dry (near sea level)
Alanine
Aluminum Oxide
Amber
Ammonia
Aniline
Anthracene
B-100 Bone-Equivalent Plastic
Bakelite
Barium Fluoride
Barium Sulfate
Benzene
Beryllium oxide
Bismuth Germanium oxide
Blood (ICRP)
Bone, Compact (ICRU)
Bone, Cortical (ICRP)
Boron Carbide
Boron Oxide
Brain (ICRP)
Butane
N-Butyl Alcohol
C-552 Air-Equivalent Plastic
Cadmium Telluride
Cadmium Tungstate
Calcium Carbonate
Calcium Fluoride
Calcium Oxide
Calcium Sulfate
Calcium Tungstate
Carbon Dioxide
Carbon Tetrachloride
Cellulose Acetate, Cellophane
Cellulose Acetate Butyrate
Cellulose Nitrate
Ceric Sulfate Dosimeter Solution
Cesium Fluoride
Cesium Iodide
Chlorobenzene
Chloroform
Concrete, Portland
Cyclohexane
1,2-Ddihlorobenzene
Dichlorodiethyl Ether
1,2-Dichloroethane
Diethyl Ether
N,N-Dimethyl Formamide
Dimethyl Sulfoxide
Ethane
Ethyl Alcohol
Ethyl Cellulose
Ethylene
Eye Lens (ICRP)
Ferric Oxide
Ferroboride
Ferrous Oxide
Ferrous Sulfate Dosimeter Solution
Freon-12
Freon-12B2
Freon-13
Freon-13B1
Freon-13I1
Gadolinium Oxysulfide
Gallium Arsenide
Gel in Photographic Emulsion
Glass, Pyrex
Glass, Lead
Glass, Plate
Glucose
Glutamine
Glycerol
Guanine
Gypsum, Plaster of Paris
N-Heptane
N-Hexane
Kapton Polyimide Film
Lanthanum Oxybromide
Lanthanum Oxysulfide
Lead Oxide
Lithium Amide
Lithium Carbonate
Lithium Fluoride
Lithium Hydride
Lithium Iodide
Lithium Oxide
Lithium Tetraborate
Lung (ICRP)
M3 Wax
Magnesium Carbonate
Magnesium Fluoride
Magnesium Oxide
Magnesium Tetraborate
Mercuric Iodide
Methane
Methanol
Mix D Wax
MS20 Tissue Substitute
Muscle, Skeletal
Muscle, Striated
Muscle-Equivalent Liquid, with Sucrose
Muscle-Equivalent Liquid, without Sucrose
Naphthalene
Nitrobenzene
Nitrous Oxide
Nylon, Du Pont ELVAmide 8062
Nylon, type 6 and type 6/6
Nylon, type 6/10
Nylon, type 11 (Rilsan)
Octane, Liquid
Paraffin Wax
N-Pentane
Photographic Emulsion
Plastic Scintillator (Vinyltoluene based)
Plutonium Dioxide
Polyacrylonitrile
Polycarbonate (Makrolon, Lexan)
Polychlorostyrene
Polyethylene
Polyethylene Terephthalate (Mylar)
Polymethyl Methacralate (Lucite, Perspex)
Polyoxymethylene
Polypropylene
Polystyrene
Polytetrafluoroethylene (Teflon)
Polytrifluorochloroethylene
Polyvinyl Acetate
Polyvinyl Alcohol
Polyvinyl Butyral
Polyvinyl Chloride
Polyvinylidene Chloride, Saran
Polyvinylidene Fluoride
Polyvinyl Pyrrolidone
Potassium Iodide
Potassium Oxide
Propane
Propane, Liquid
N-Propyl Alcohol
Pyridine
Rubber, Butyl
Rubber, Natural
Rubber, Neoprene
Silicon Dioxide
Silver Bromide
Silver Chloride
Silver Halides in Photographic Emulsion
Silver Iodide
Skin (ICRP)
Sodium Carbonate
Sodium Iodide
Sodium Monoxide
Sodium Nitrate
Stilbene
Sucrose
Terphenyl
Testes (ICRP)
Tetrachloroethylene
Thallium Chloride
Tissue, Soft (ICRP)
Tissue, Soft (ICRU four-component)
Tissue-Equivalent GAS (Methane based)
Tissue-Equivalent GAS (Propane based)
Titanium Dioxide
Toluene
Trichloroethylene
Triethyl Phosphate
Tungsten Hexafluoride
Uranium Dicarbide
Uranium Monocarbide
Uranium Oxide
Urea
Valine
Viton Fluoroelastomer
Water, Liquid
Water Vapor
Xylene