Hi Eyal,

 Yes, I think the slide good. I would like to reorder the main objectives however.  Maybe we should make them shorter too? 

My thought process with the objectives is that number 1 is our primary objective. To accomplish 1, we need to do items 2, 3, and 4.  At least, that is how I would present it to the leaders in DC.

Main Objectives:

1. Develop a data-driven, multiphase equation of state for CaF2

2. Understand the phase diagram over a broad range of pressure and temperature space

3. Understand the kinetics of the phase transitions

4. Examine the dynamics of the constitutive response

Instead of “Main Tools”, maybe we should say “Methods”?  

We could say the following:

Methods:

 1. Gun experiments at IAEC and SNL to examine EOS and constitutive response

 2. Shockless compression (THOR and Z) at SNL to understand loading rate effects

 3. Static Compression (IAEC and SNL) to map the equilibrium phase diagram

 4. Density Functional Theory (IAEC and SNL)

Seth

Sent from my iPad

On Apr 10, 2018, at 2:03 PM, Eyal Yahel <eyalyahel@gmail.com> wrote:

Dear Seth, 

1. I've asked Arnon to prepare the first draft of the proposal and hopefully we will send it in the next couple of days.

2. Arnon also prepares one slide (attached) to be included in the general presentation at the coming SC in DC. 

(Dimitri and Yoni will present it to the DGs'). 

Please feel free to change or comment on it.  

3. Referring to your Memo:

a) we would like to have the DAC measurements included in the proposal. 

Please note that we can make preliminary measurements up to (theoretically) close to 100GPa with the cells we have.

However, the tabletop XRD we have, might be insufficient for refined measurements in CaF2. 

To produce meaningful results we'll have to get to a Synchrotron... Your partnership for that is essential.

What about obtaining data on the melting curve? 

Currently we can measure the MC up to 3500K but somewhat limited with the heating laser. 

I assume CaF2 is transparent (is it so for the entire phase space?), so in order to heat it we need to develop new method, e.g., to apply metallic sheet under the sample...

b) MPEOS - IAEC uses analytic formulation for multiphase EOS modelling, using traditional decomposition of the energy to different terms (E=Ec+Ei+Ee...) and as means to interpolate between sparse data points or extrapolate.  

Using the analytic EOS it is possible to translate into tabular format, including SESAME.

IAEC will take the EOS analytic modelling effort and will work with SNL to translate to any format required.

We think that no multiple EOS modelling is required.

c) Spall studies - We mentioned this part since we think that the information regarding strength can be deduced from the main program.

Obviously this is a secondary goal which need to be further discussed in the first meeting we'll have.

d) DFT - We agree that DFT calculations are needed. 

To construct the mode of collaboration we need to understand your methods, e.g., how did you calculate the Hugoniot and other questions. 

Therefore, I think this topic should be discussed between us, maybe at the first meeting, and the decision how to include it will be taken later.

To address your question, we can work in two formalisms:

   i) Within the quasi-harmonic approximation. 

      It is possible to calculate the P-T phase diagram of CaF2, up to pressures of several 10's of GPa (above 40PGa of course)

   ii) 0K calculation to obtain the stable phases then probably add the thermal part.

f) I completely agree that meetings should take place once a year to coordinate the project.

We can host the first one in Israel or to your convenience it can be held at SNL 

(with the benefit that our guys would be able to visit the experimental facilities).

Thanks, 

Eyal 

On Fri, Apr 6, 2018 at 7:05 PM, Root, Seth <sroot@sandia.gov> wrote:

Hello Eyal,

 

Please find attached a response memo for the dynamic phase transition (DPT) proposal on calcium fluoride. We did have some questions, which are asked in the memo. Regardless of those questions, we think the DPT work can begin moving forward. 

 

The first step is to submit an official proposal to our respective leadership organizations. Is there a template/format that we need to use for the proposal?

 

Eyal – would you like to put together the first draft of the official proposal? If you prefer, I can also put together the first draft if you send me the template file.

 

Once the proposal is approved, we should plan on having a meeting with the PIs (Benny, Arnon, Eyal, Seth, and Dawn) to discuss the fine details of the work.

 

We look forward to a successful collaboration!

 

Seth

 

 

 

—————————————————————————

Seth Root

Sandia National Laboratories

Office: 505-284-1749

Mobile: 505-328-6322

—————————————————————————

 

 

From: Eyal Yahel <eyalyahel@gmail.com>
Date: Monday, November 13, 2017 at 7:02 AM
To: Seth Root <sroot@sandia.gov>, Dawn Flicker <dgflick@sandia.gov>, "Fox, Glenn A." <fox7@llnl.gov>, "Specht, Paul Elliott" <pespech@sandia.gov>, "Mattsson, R" <trmatts@sandia.gov>, "Benage, John F" <jfbenag@sandia.gov>, "Sarrao, John Louis (LANL)" <sarrao@lanl.gov>
Cc: Elazar Sarid <elazarsa@soreq.gov.il>, Melchior Aviva <avimel@gmail.com>, Avi Ravid <aviravid@soreq.gov.il>, "arnony@nrcn.gov.il" <arnony@nrcn.gov.il>, "vitalyP@nrcn.gov.il" <vitalyP@nrcn.gov.il>
Subject: Re: [EXTERNAL] NNSA/IAEC Material Science Topic

 

Dear all - 

 

We hope this mail finds you well. 

 

As Seth suggested, we invested additional thought on the directions related to dynamic properties of materials which we can effectively collaborate on.

In the attached file, we grouped the experiments into three sections:

- dynamic phase transitions

- dynamic properties of additive manufactured samples

- effects of microstructure on dynamic properties (AM samples as a model system)

 

In addition we, stated the IAEC POC's which are assigned to the collaboration. 

We need to conclude the correspondence before the end of 2017 so we can include it in the work-plan of 2018 (both parties).

 

I suggest that final remarks will be sent in the coming weeks to finalize the proposals. 

 

Best Wishes, 

Eyal  

 

 

 

On Tue, Sep 5, 2017 at 8:01 PM, Root, Seth <sroot@sandia.gov> wrote:

Hello Everyone,

 

Considering Eyal’s and Dawn’s emails, I am emailing to see if people have given any more thought to the dynamic phase transition proposals.

 

IAEC has interest in following: Tin, Si/Ge, Ti, CaF2

Sandia has interest in Co and CaF2

 

Are there other materials of interest? According to Eyal, Si/Ge is probably out for now until we can get more reliable samples.

 

For reference, I’ve included a phase digram of CaF2 from Carzola and Errandonea (Phys. Rev. Lett. 113, 235902, 2014). There is another phase diagram in J. R. Nelson PRB 85, 054118, 2017. I have attached both papers as well.  The alpha-gamma transition is easy to obtain using either Sandia or IAEC gun systems. One topic of interest might be to try to reach the delta phase using IAEC’s preheat capabilities and by shock compressing porous CaF2 samples (pressed powders). We could try to develop shock-ramp experiments to explore the gamma-delta phase boundary.

 

We also have interest in doing shock-ramp experiments on single crystal CaF2 near the incompressibility region on the Hugoniot (~100 GPa). We could submit a joint proposal for Z’s fundamental science program looking at shock-ramped CaF2. Furthermore, doing DFT and possibly DAC work on the phase diagram above 30 GPa would be of great value.

 

Does IAEC have a specific region of interest for CaF2? Sound speed measurements on the alpha-gamma transition?

 

I’ve also included a paper on our work on Tin where we did use the shock-ramp platform.  This paper should provide some perspective as to what Z can do with the shock-ramp and show what we have already completed in our work on Tin.

 

 

 

 

Seth

 

—————————————————————————

Seth Root

Sandia National Laboratories

Office: 505-284-1749

Mobile: 505-328-6322

—————————————————————————

 

 

From: Eyal Yahel <eyalyahel@gmail.com>
Date: Saturday, August 19, 2017 at 1:33 PM
To: Dawn Flicker <dgflick@sandia.gov>
Cc: "Sarrao, John Louis (LANL)" <sarrao@lanl.gov>, "Fox, Glenn A." <fox7@llnl.gov>, Elazar Sarid <elazarsa@soreq.gov.il>, Seth Root <sroot@sandia.gov>, "Specht, Paul Elliott" <pespech@sandia.gov>, "Mattsson, R" <trmatts@sandia.gov>, "Benage, John F" <jfbenag@sandia.gov>, "Molina, Vanessa M" <vmmolin@sandia.gov>, Melchior Aviva <avimel@gmail.com>, Avi Ravid <aviravid@soreq.gov.il>, "arnony@nrcn.gov.il" <arnony@nrcn.gov.il>, "vitalyP@nrcn.gov.il" <vitalyP@nrcn.gov.il>
Subject: Re: [EXTERNAL] NNSA/IAEC Material Science Topic

 

Dear all, 

 

Sorry for being slow in our reply.

 

I agree with Dawn regarding the workshop in October, and I suggest to check its relevance towards the beginning of 2018.

 

Below please find some comments Arnon and Vitaly drafted.

 

In regard to possible AM materials for both AM proposals:

1. NRCN cannot provide AM stainless steel or pure titanium samples at timescales relevant for this study. i.e. We can provide specimens of Ti64 produced by EBM and SLM and AI10SiMg produced by SLM.

2. Nevertheless, we interested in studies of other AM materials (such as stainless steel 304L), but to carry out research plan, the specimens should be supplied by the NNSA.

For the first proposal on AM - The dynamic evaluation of AM materials is a part of a broader
proposal on characterization of AM materials which is currently concentrated on Ti64. 

Therefore we think that the dynamic part of this proposal should also be done
on the Ti64 alloy, at least at the first stage.

For the second proposal (Effect of microstructure - pores, gas bubbles, inclusions- on
dynamic behavior of AM materials) - The only material (except Ti64) available now (to NRCN)
to begin with is AI10SiMg. This aluminum alloy can be manufactured using SLM method with
powder bed. The resulting porosity is of about 0.5-1.5%, while pores' of 1-10 microns in size
are actually argon bubbles. The subsequent HIP post-processing can reduce the pores' size,
while the argon pressure will increase. By varying the HIP parameters one can control the
pores size/argon pressure to study the effect of the latter on the dynamic
behavior of the alloy and particularly on the spall strength.

Dynamic phase transitions

1.        In addition to the potential materials Dawn listed, the discussion also included Sn,
with an interest mostly on its melting along the Hugoniot at about 70 GPa (although
it does also have a solid-solid transition at a low pressure). It seems that this is
relevant to several studies presented during the conference at St. Louis. NRCN and SNRC
suggested to apply sound velocity techniques to better investigate the transition.
Our facilities will allow us to perform experiments up to about the melting point,
and we suggest that these experiments should be complemented with experiments
at higher pressures by using NNSA's guns with higher impact velocities or other high
pressure facilities. In addition, we suggest to perform experiments with elevated
initial temperature which we can perform currently on our single stage gas gun
system. NRCN can also contribute Ab-Initio DFT calculations for all relevant phases
and calibration of equation of state. It will be valuable to validate such against the
experiments as well as modeling by other parties.

2.        Si and Ge are still of interest to NRCN, but because of the higher complexity- both of
the experimental techniques and of the physical processes involved, it is suggested
that this proposal will re-evaluated and incorporated into the collaboration at a later stage.

3.        Of the other materials suggested, IAEC is interested in studies of pure Ti and CaF, but
further work is needed in order to write a detailed proposal.

There is a small correction to the list names of the people present in the meeting.

Here is the correct list for the Israeli side:

SNRC: Avi Ravid, Beni Glam; IAEC: Eli Gudinetsky; NRCN: Vitaly Paris, Arnon Yosef-Hai

Dynamic loading capabilities of IAEC labs:

1.       Gas gun (NRCN): 25-mm bore gas gun, velocity capability is up to 1 km/sec, VISAR
diagnostics.

Current efforts focus on setup impact experiments with pre-heating targets to temperatures
up to 1000°C.

2.       SHPB (NRCN): 0.5’’ and 1" Hopkinson bar systems; capabilities to test standard
compressive samples and shear samples; strain rates are 10³-10⁴ sec^-1,

3. Powder gun (SNRC):40-mm bore, velocities up to 2.5 km/sec, VISAR diagnostics

Calculations from first principles capabilities (NRCN):

Calculations of the lattice parameters, lattice stability and phonon dispersion curves of solid
phases of metals are done within density functional theory (DFT). Results of DFT
calculations are employed to estimate the entropy and free energies of the phases (e.g., 
alpha and omega phases of Ti).

First principles calculations of representative semiconductor (Si) and representative metal
(Ti) performed using density-functional perturbation theory. 

EOS study of tin from first principles using DFT is planned.

 

Dawn - 

 

We clearly have 2-3 proposals. 

I think the next step is to have a plan for each and organize it in a proposal to be submitted to the Chief scientists.

 

Eyal 

 

 

 

On Tue, Aug 8, 2017 at 7:50 PM, Flicker, Dawn G <dgflick@sandia.gov> wrote:

Eyal –

    It doesn’t look like it would be practical to have the materials workshop at Argonne this time.

Sandia could host, but we would need have pretty firm plans within the next few weeks. We will

start looking at possible arrangements for that week. 

 

I haven’t seen any responses to my email of 7/25.  It makes the most sense to have a workshop if we think there are some good areas to explore in depth.

 

Thanks

Dawn

 

From: Eyal Yahel [mailto:eyalyahel@gmail.com]
Sent: Sunday, August 06, 2017 2:02 PM
To: Flicker, Dawn G <dgflick@sandia.gov>; Sarrao, John Louis (LANL) <sarrao@lanl.gov>; Fox, Glenn A. <fox7@llnl.gov>
Cc: Elazar Sarid <elazarsa@soreq.gov.il>
Subject: [EXTERNAL] NNSA/IAEC Material Science Topic

 

Dear all, 

 

I wish to thank Dawn for organizing the meeting in St. Louis.

In the next couple of days we will update on the action items Dawn drafted. 

 

In the meantime, I would like to check on Dawn's suggestion to have a small workshop at Argonne (APS/DCS) to:

 

1. To get acquainted with the facility (Israelis)

2. To have extended presentations and discussions on the proposals   

3. Use it as mid year meeting on dynamical experiments.

 

I suggest to take advantage of the APS in Wisconsin (some of the relevant IL PI's will attend) and couple the workshop to the week that follows it, namely, Monday the 30.10.17

Would that work for the US PI's? 

 

Eyal

 

--

Eyal Yahel, Ph.D.
Chief Scientist NRCN
P.O.Box 9001 Beer-Sheva,
Israel, 84190

 

--

Eyal Yahel, Ph.D.
Chief Scientist, NRCN
P.O.Box 9001 Beer-Sheva,
Israel, 84190

--

Eyal Yahel, Ph.D.
Chief Scientist, NRCN
P.O.Box 9001 Beer-Sheva,
Israel, 84190

<NNSA-IAEC - CaF2 -201804 Summary slide.pptx>