Matter Element and MaterialP

source/element-kinds.md

@@ -214,26 +214,6 @@ Element parameter groups associated with this element kind are:
 - [**MetaP**](#s:meta.params): Meta parameters.
 - [**ReferenceP**](#s:ref.params): Reference parameters.
 
-%---------------------------------------------------------------------------------------------------
-(s:foil)=
-## Foil Element
-
-Material that can strip electrons from a particle.
-Will also cause energy loss and diffusion.
-
-Under Construction...
-
-Element parameter groups associated with this element kind are:
-- [**ApertureP**](#s:aperture.params): Aperture parameters.
-- [**BodyShiftP**](#s:bodyshift.params): Orientation of element with respect to its nominal position.
-- [**FloorP**](#s:floor.params): Floor position and orientation.
-- [**MetaP**](#s:meta.params): Meta parameters.
-- [**ReferenceP**](#s:ref.params): Reference parameters.
-- [**ReferenceChangeP**](#s:refchange.params): Reference energy change and/or reference time correction.
-- [**TrackingP**](#s:tracking.params): Tracking parameters.
-
-The length of this element is considered to be zero so if `length` is specified, it must be zero.
-
 %---------------------------------------------------------------------------------------------------
 (s:fork)=
 ## Fork Element
@@ -358,6 +338,24 @@ Element parameter groups associated with this element kind are:
 
 The length of this element is considered to be zero so if `length` is specified, it must be zero.
 
+%---------------------------------------------------------------------------------------------------
+(s:matter)=
+## Matter Element
+
+Materials which fully occupy the beamline, like targets, (stripper-)foils, vacuum windows, gas cells or degraders.
+This element can cause energy-loss, angualar and energy straggling, as well as change of charge state or particle type.
+
+Element parameter groups associated with this element kind are:
+- [**ApertureP**](#s:aperture.params): Aperture parameters of the outer (blocking) aperture.
+- [**BodyShiftP**](#s:bodyshift.params): Orientation of element with respect to its nominal position.
+- [**FloorP**](#s:floor.params): Floor position and orientation.
+- [**MetaP**](#s:meta.params): Meta parameters.
+- [**ReferenceP**](#s:ref.params): Reference parameters.
+- [**ReferenceChangeP**](#s:refchange.params): Reference energy change and/or reference time correction.
+- [**TrackingP**](#s:tracking.params): Tracking parameters.
+- [**MatterP**](#s:matter.params): Matter parameters.
+
+
 %---------------------------------------------------------------------------------------------------
 (s:multipole)=
 ## Multipole Element

source/element-parameters.md

@@ -126,6 +126,9 @@ element-by-element.
 ```{include} parameters/magneticmultipole.md
 ```
 
+```{include} parameters/material.md
+```
+
 ```{include} parameters/meta.md
 ```
 

source/parameters/aperture.md

@@ -12,7 +12,7 @@ refp1:                            # [string] user-defined name
   location: ENTRANCE_END          # [string] Aperture location switch
   aperture_shifts_with_body: ...  # [Boolean] ... TODO: describe ... TODO: default
   vertices: {}                    # [Dictionary] ... TODO: describe ...
-  material: ""                    # [string] Material of the Aperture
+  material: ""                    # [MaterialP] Material of the Aperture
   thickness: 0                    # [m] Real number
 ```
 
@@ -103,7 +103,6 @@ The difference between the two lists is simply that lines 2 and 3 are switched a
 ### material
 
 The `material` parameter sets the material of the aperture. 
-Using chemical formulas like `Cu` and `Fe` is the most portable.
 
 ### vertices component
 

source/parameters/material.md

@@ -0,0 +1,54 @@
+(s:material.params)=
+## MaterialP:  Definition of materials
+
+The definition of materials is inspired by Geant4's material handling. One can either use the name, which is the symbol of an element (`"G4_Cu"`, `"G4_H"`, ...) or compound (`"G4_STAINLESS-STEEL"`).
+In the future all elements and materials in the [G4 Manual](https://geant4-userdoc.web.cern.ch/UsersGuides/ForApplicationDeveloper/html/Appendix/materialNames.html) will be supported.
+
+Alternatively custom elements can be defined by
+
+```{code} yaml
+ElementP:
+- name:      # [string] The name of the material
+- density:   # [kg/m^3] The density of the material
+- Z:         # [int]    The atomic number
+- A:         # [int]    The mass number (equals Z+N)
+- N:         # [int]    The neutron number
+- m:         # [u]      The atomic mass
+```
+
+and compunds by
+
+```{code} yaml
+CompundP:
+- name:      # [string] The name of the material
+- density:   # [kg/cm^3] The density of the material
+- elements:  # List of MaterialP
+- ratio:    # List of ratios of the elements
+```
+
+### Examples
+`MaterialP: "G4_Cu"` or `MaterialP: "G4_STAINLESS-STEEL"` or define a new material.
+
+Liquid deuterium can be defined with the `ElementP` parameters:
+```{code} yaml
+MaterialP:
+- name: "Deuterium(l)"
+- density: 160
+- Z: 1
+- A: 1
+- m: 2.01
+```
+and deuterated polyethylene (C2H4) can be defined based on the previous definition
+```{code} yaml
+MaterialP:
+- name: "deutPE"
+- density: 1050
+- elements:
+  - "G4_C"
+  - "Deuterium(l)"
+- ratio:
+  - 2
+  - 4
+```
+
+