Discussion with Marco

General Overview
Questions or Discussion.

7/10/2020 (with Umberto, Skype)
- Pick up typical elements from massive stars Sr, Zr (weak s-process massive stars) - 98% of these elements come from massive stars - To reproduce solar system composition - GCE - Last generation stars (typical composition) - 0.01Z – alpha elements 0.06%, (Canfar) massive star - Ge (weak s massive stars; 70 s-only) 70Ge/Ge72 → (73Ge(n,g) nTOF) impact - C-shell (kippenhaman diagram) - See C-composition - Mesa.py → kippenhahn→this should be ok (stra.log from mesa), kip_cont - 4300 – 4400 cycle, Mass < 1.25-2 mass (check middle of the zone)

import mesa as ms ls st1=ms.star_log('.') st1.kippenhahn? st1.kippenhahn(1,'logtimerev') plt.gca.invert_yaxis st1.kippenhahn(1,'logtimerev') plt.gca.invert_xaxis st1.kippenhahn(1,'model')

- 94Zr(n,g) - PPN - Networksetup.txt → change rate from 1 to XX - ININET = 3 in ppn_physics (this means read reaction rate from networksetup.txt)

9/1 - 9/7/2019 (NuGrid Meeting, Budapest)
- To change reaction rates by factors, change rate_factor in NuPPN/physics/source/physics_knob.F90 (Ashly).

- OZone is single zone trajectory (Adria).

- PPN doesn't handle convection, but MPPNP does. Running MPPPNP is almost same as running MESA, so no trajectory input is needed. MPPNP needs to be run on cluster computer for efficient computation.

- How to avoid reaching MAX_SUBSTEP and calculation stopping?

- Why some trajectory files (in example codes) seem like time-reversal? (temperature and density decreases with time, e.g., M25_ccsn) --> because the time is delta t (time interval).

- Why some trajectory files (in example codes) contain same time but different temp and rho (e.g., M25_weak_s/center, mixed)? --> because the time is delta t.

8/21/2019 (read a paper)
- I like Marco's this paper (about 12C+12C in massive stars for s-process; hard to read, but important and related to my interest].

7/17/2019
- If I need to make trajectory.input from MESA. How? (which output variables in MESA?; especially case of shell burning)

--> Not needed. Already there exist many calculations using different patters of metallicity, solar mass, initial abundances on http://www.canfar.net/en. For example, check https://www.canfar.net/storage/list/nugrid/data/set1ext/set1.2. or https://www.canfar.net/storage/list//nugrid/data/set1ext/set1.2/see_wind/M2.00Z2.0e-2/. Download h5.out. If you want to know MESA input files, check inlist and reaction network directory.

- Is it normal that Carbon core produces neutron more than He shell (for s-process). If so, why no s-process occurs in the Carbon core?

Depends on reaction network that I set. If no neutron poisons are set well (MESA is not good at it due to limited network and isotopes), that's very possible. Marco suggested to read this paper

- Why 22Ne(a,n) should be the neutron source? Other reactions such as 18O(a,n) cycle back or be neutron poison?

Because of possible neutron recycling. For example, 12C(n,g) --> 13C(a,n) --> net neutron is 0. Likewise, 16O(n,g)->17O(a,n) and 21Ne(n,g) --> 22Ne(a,n). 22Ne (and 13C) are special because there exist many already.

- How to install MPPNP? (how to install SE library and openmpi?)

Not discussed this time.

- abu_chart.py error (currently I need to hard-code in data_plot.py)

Not discussed this time.

- What is tppnp?

MPPNP specialized for extracting trajectory.

- How to change nuclear reaction rate? (NuPPN/physics/NPDATA)

Change NuPPN/physics/source/vital.F90 (remember to make in the running directory), ppn_physics.input Check Marco's paper too.

6/30/2019
- How to install NuPPN