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baboons [2014/06/09 17:59]
cook
baboons [2014/06/10 18:49]
brown Added help for humans take two
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   - The mean life of the decaying particle X -> 2n  (some magic decay. Not very physical, probably. But hey, we don't actually know what WIMPS are).   - The mean life of the decaying particle X -> 2n  (some magic decay. Not very physical, probably. But hey, we don't actually know what WIMPS are).
   - The energy of these neutrons (although if it is high enough, it may not matter too much?)   - The energy of these neutrons (although if it is high enough, it may not matter too much?)
-  - The abundance of X. +  - The abundance of X. Jedamzik, 2004: 7Be is suppressed if O(10^-5) neutrons per proton are injected. Increases D/H. Lifetime of ~1000 s required
   - n interaction rates with every other nucleus. ​   - n interaction rates with every other nucleus. ​
   - Mass of the WIMP. Chosen to be 100 GeV, based on the wikipedia WIMP entry, the font of all wisdom. ​   - Mass of the WIMP. Chosen to be 100 GeV, based on the wikipedia WIMP entry, the font of all wisdom. ​
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 from CDMS in 2004 suggests that this value isn't too far off.  from CDMS in 2004 suggests that this value isn't too far off. 
 +
 +**Code: ** 
 +
 +  - **How to add an Isotope to bigbang**
 +    - Add pointer identifier, id, in network.dek (e.g. ini56)
 +    - In subroutine init_bigbang:​
 +      - Add 1 to ionmax ​
 +      - Set id number (usually +1 of the last isotope)
 +        - id = number
 +      - Set ratnam (name e.g. "​ni56"​)
 +        - ionam (id) = isotope name
 +      - Set zion (# of protons)
 +        - zion (id) = Z
 +      - Set aion (mass number)
 +        - aion (id) = A
 +      - Set bion (binding energy)
 +        - bion (id) = binding energy
 +    - In net_input
 +      - Add initial abundance in xin
 +        - xin (id)
 +    - In init_isotope_rate_pointers
 +      - Set pointer to 0
 +        - id = 0
 +  - **How to add a Reaction Rate to bigbang**
 +    - Add reaction subroutine
 +    - Add reaction and reverse reaction pointers, irid and irrid, in network.dek
 +    - In subroutine init_bigbang:​
 +      - Add 2 to nrat
 +      - Set id numbers, usually +1 of last reaction
 +        - irid = number
 +        - irrid = number + 1
 +      - Set names
 +        - ratnam (irid) = reaction name
 +        - ratnam (irrid) = reverse reaction name
 +    - In subroutine init_isotope_rate_pointers
 +      - Set pointers to 0
 +        - irid = 0
 +        - irrid = 0
 +    - In subroutine bigbangrat
 +      - Call reaction subroutine
 +        - call rate_id (btemp,​bden,​ratraw(irid),​dratrawdt(irid),​dratrawdd(irid),​ratraw(irrid),​dratrawdt(irrid),​dratrawdd(irrid)
 +          - Arguments
 +            - temp => temperature in K
 +            - den => density in g/cm^3
 +            - fr => forward reaction rate, N_a<​sigma v>
 +            - dfrdt => derivative of fr with respect to temp
 +            - dfrdd => derivative of fr with respect to den
 +            - rr => reverse reaction rate, N_a<​sigma v>
 +            - drrdt => derivative of fr with respect to temp
 +            - drrdd => derivative of fr with respect to den
 +    - In subroutine bigbangtab
 +      - Add density dependence
 +        - dtab(irid) = 1.0d0 for decay
 +        - dtab(irid) = bden for 2-body interaction
 +        - Likewise for irrid
 +    - In subroutine rhs:
 +      - Add dy/dt terms
 +        - dydt(isotope1) = dydt(isotope1) - y(isotope1) * y(isotope2) * rate(irid)
 +        - dydt(isotope2) = dydt(isotope2) - y(isotope1) * y(isotope2) * rate(irid)
 +        - dydt(output) = dydt(output) + y(isotope1) * y(isotope2) * rate(irid)
 +        - Likewise for reverse reaction
 +    - In subroutine bbigbang
 +      - Add tree calls for reaction if they don't exist
 +        - call tree(isotope1,​isotope1,​eloc,​neloc,​nterms,​nzo,​iloc,​jloc,​np)
 +        - call tree(isotope1,​isotope2,​eloc,​neloc,​nterms,​nzo,​iloc,​jloc,​np)
 +        - call tree(isotope2,​isotope1,​eloc,​neloc,​nterms,​nzo,​iloc,​jloc,​np)
 +        - call tree(isotope2,​isotope2,​eloc,​neloc,​nterms,​nzo,​iloc,​jloc,​np)
 +        - call tree(output,​isotope1,​eloc,​neloc,​nterms,​nzo,​iloc,​jloc,​np)
 +        - call tree(output,​isotope2,​eloc,​neloc,​nterms,​nzo,​iloc,​jloc,​np)
 +    - In subroutine sbigbang
 +      - Add Jacobian elements
 +        - For example, for d(isotope1)/​d(isotope2)
 +          - a1 = -y(isotope1)*ratdum(irid)
 +          - nt = nt + 1, only if this Jacobian element doesn'​t already exist
 +          - iat = eloc(nt), only if this Jacobian element doesn'​t already exist
 +          - dfdy(iat) = dydy(iat) + a1
 +          - xsum(isotope2) = xsum(isotope2) + a1 * mion(isotope1)
 +          - Likewise for d(isotope1)/​d(isotope1),​ d(isotope2)/​d(isotope1),​ etc.
 +        - For example, for d(output)/​d(isotope2)
 +          - a1 = -y(isotope1)*ratdum(irid)
 +          - nt = nt + 1, only if this Jacobian element doesn'​t already exist
 +          - iat = eloc(nt), only if this Jacobian element doesn'​t already exist
 +          - dfdy(iat) = dydy(iat) + a1
 +          - xsum(isotope2) = xsum(isotope2) + a1 * mion(output)
 +          - Likewise for d(output)/​d(isotope1)
 +        - Do likewise for the reverse reaction rate, making sure not to repeat any of the above lines that shouldn'​t be done if the element already exists
 +
 +
 +
  
 Reference Papers: ​ Reference Papers: ​
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 Kamionkowski 1994. Diffuse Gamma Rays from WIMP Decay and Annihilation [[http://​arxiv.org/​pdf/​astro-ph/​9404079v1.pdf]] Kamionkowski 1994. Diffuse Gamma Rays from WIMP Decay and Annihilation [[http://​arxiv.org/​pdf/​astro-ph/​9404079v1.pdf]]
 +
 +Pierre Salati, 2014. Dark Matter Annihilation in the Universe [[http://​arxiv.org/​pdf/​1403.4495.pdf]]
  
 **Logbook** ​ **Logbook** ​
baboons.txt ยท Last modified: 2014/06/13 10:24 by cook