News

Davide Curreli Appointed as Assistant Director of CPMI

August 7, 2013

CPMI’s own postdoc, Davide Curreli, has be selected to be one of the new plasma professors at the University of Illinois at Urbana-Champaign. His new position has brought him also the position of being an Assistant Director for the Center for Plasma and Material Interactions.

Congratulations Davide!

CPMI Hires New Postdoc – Kishor Kalathiparambil

August 7, 2013

After going through a series of highly qualified applicants, CPMI has selected Kishor Kalathiparambil as a post doc. Kishor has worked around the world looking in various aspects of plasma material related fields and received his PhD in May of 2012 from the Institute of Plasma Research from Gandhinagar India.

Congratulations Kishor!

Plasma Surface Interactions – Scientific Discovery through Advanced Computing (PSI-DAC)

June 26, 2013

As part of the Plasma Surface Interactions: Bridging from the Surface to the Micron Frontier through Leadership Class Computing SciDAC project, we are working to better understand how plasma facing components (PFCs) will interact with burning fusion plasmas. Researchers at CPMI are investigating processes like sputtering, re-deposition, and evolving surface roughness with Monte Carlo, binary collision approximation (BCA) codes. We have designed and developed several surface roughness models for TRIDYN (resulting in the Fractal TRIDYN code, or FTRIDYN) and are using these to investigate the role surface roughness plays in ballistic ion-surface interactions.

    Enlarge Image of Sputtering Yield of Deuterium Incident on Beryllium

Click to Enlarge: D on Be Sputtering Yield

TRIDYN:
W. Möller, W. Eckstein, J.P. Biersack, Tridyn-binary collision simulation of atomic collisions and dynamic composition changes in solids, Computer Physics Communications, Volume 51, Issue 3, November 1988, Pages 355-368, ISSN 0010-4655, 10.1016/0010-4655(88)90148-8.
http://www.sciencedirect.com/science/article/pii/0010465588901488

Fractal TRIM:
D.N. Ruzic and H.K. Chiu, J. Nucl. Mater. 162-164 (1989) 904.

Experiment:
R.P. Doerner, D. Nishijima, T. Schwarz-Selinger, Nucl. Fusion 52 (2012) 103003

(Updated 2015)

Lithium Injector

June 26, 2013

Study of liquid lithium has increased as of late for its applicability in fusion energy. Liquid lithium implemented in the divertor of a fusion device may prove to be the path to a fusion device that produces significantly more energy than it consumes. Liquid lithium benefits a fusion device by gettering cold hydrogenic species at the wall of a fusion device, raising edge temperatures, and increasing energy confinement times. However, this effect subsides as the lithium passivates, or reacts to form different compounds. Maintenance of a clean lithium surface therefore is important, and so is the study of clean lithium surfaces.

The lithium injector developed at UIUC imparts the ability to place controlled amounts of visibly impurity-free liquid lithium into a vacuum chamber. Loaded with lithium that may be partially oxidized on the surface, ejection through a nozzle ensures via the high surface tension of lithium that the oxide, hydroxide, and hydride impurities that form on lithium surfaces are confined to the injector tube, and that only lithium exits. This injector is used in the Materials Characterization Test Stand (MCATS) chamber to study the contact angle of liquid lithium, as well as used to fill the Liquid-Metal Infused Trenches (LiMIT) that are implemented on the Solid-Liquid Lithium Divertor Experiment (SLiDE) chamber with clean lithium.

(Updated 2013)

MCATS – Materials Characterization Test Stand

June 26, 2013

Liquid metals have received increased attention within the fusion community as of late. Liquid lithium, especially, has been the target of much interest for its ability to getter impurities and cold hydrogenic species at the walls of fusion devices. Lithium has been shown in several fusion devices to increase energy confinement times and to reduce the frequency of edge localized modes, plasma instabilities which cause large deposits of energy to the first wall of fusion devices. Inclusion of liquid metals in a fusion device requires, however, that the liquid metal wet the substrate on which it is placed. Beading of the liquid is undesirable.

The Materials Characterization Test Stand (MCATS) chamber at CPMI was specifically designed to investigate the wetting phenomena of liquid metals on various fusion relevant substrates. A moveable stage mounted either on a plate heater, or with strip heaters attached to the back side allows for placement of several droplets of liquid metal on various surfaces, in order to study the contact angle of a liquid metal on the surface. Contact angles of liquid lithium on various fusion relevant surfaces have been studied, as well as methods for the reduction of the critical wetting temperature of lithium on these surfaces.

MCATS also allows for the study of the compatibility of liquid metals with various solid surfaces. A pool of liquid metal in a stainless steel cup is mounted on the stage. A rotary motion feedthrough driven by an external motor allows for study of erosion of different solid materials in liquid metal. Most recently, this device showed the strong attack of copper by liquid gallium.

(Updated 2013)

Seebeck Apparatus

June 26, 2013

Exposure to very large heat fluxes as well as large radiation loads inducing strong wear threatens to limit the lifetime of solid plasma facing component materials in fusion energy devices. Liquid metal devices, however, do not suffer the same ill effects. Liquid lithium, in particular, has shown promise as a potential candidate for a plasma facing component material. Several methods exist to introduce lithium into fusion devices, however, one of the most unique methods of doing so is the Liquid-Metal Infused Trenches concept of CPMI. LiMIT relies on thermoelectric magnetohydrodynamics (TEMHD) to propel a liquid metal down a series of trenches. TEMHD flow is based on the interaction of a thermoelectric current with a magnetic field.

The source of the thermoelectric current in the LiMIT device arises from the junction between the flowing liquid metal and the trench wall material. A thermal gradient across this interface gives rise to the thermoelectric current. An analogy may be constructed by considering the interface to be composed of two junctions, the top portion of the trench would constitute the hot junction of a thermocouple, while the bottom portion of the trench would constitute the cold junction. Since the interfacial voltage between the two materials is a function of temperature, the temperature difference gives rise to a voltage difference, which drives a current.

The magnitude of the current driven is proportional to the relative thermopower, or the difference in Seebeck coefficient, between the two materials. To generate data on the Seebeck coefficient of a wide variety of materials, an apparatus was constructed at CPMI. Shown in the photo above, measurement of the Seebeck coefficient of many fusion relevant materials is possible. A library of Seebeck coefficients is being compiled, and measurements are ongoing.

(Updated 2013)

Posdoctoral Position Announcement for CPMI at the University of Illinois at Urbana-Champaign

June 20, 2013

The Center for Plasma Material interactions (CPMI) at the University of Illinois at Urbana Champaign is looking to fill in a position at the post-doctoral research associate level, who will work on research areas relevant to plasma material interactions for several applications. The Center for Plasma-Material Interactions currently has 12 graduate students, and over 20 undergraduate researchers. The primary emphasis is experimental and computational study of plasma relating to the manufacturing of semiconductor devices (plasma-based lithography, plasma etching, PVD sputtering, PECVD thin-films) and the edge-region of future fusion energy devices (lithium walls, lithium technology, edge localized modes, mixed material sputtering at elevated temperature). In addition, CPMI is also a part of the “NSF I/UCRC center for Lasers and Plasmas for Advanced Manufacturing” and has many new opportunities for research projects, particularly in the field of atmospheric pressure plasmas. This particular position will work both in semiconductor materials and in fusion engineering. CPMI currently has a total of 13 major experimental systems and is expected to grow as we take on new projects. The hired post-doc is expected to closely work with Prof. David Ruzic in managing research activities in the lab and conduct experiments while assisting students with research.

Primary responsibilities include, but are not limited to:
– Work with Prof. David Ruzic in managing research activities
– Advice and assist students with research
– Conduct original research on CPMI projects
– Work with industrial research partners and collaborations on projects
– Identify and grow new research directions
– Monitor proposal solicitations and write grant proposals
– Meeting deadlines, milestones and write reports for funding agencies
– Report results in peer-reviewed publications and conferences

The postdoctoral researcher’s development at CPMI will also be enhanced through a program of structured mentoring activities. The goal of this program is to provide the skills, knowledge and experience to prepare the successful candidate to excel in his/her career path. To accomplish this goal, the mentoring plan includes career planning assistance, and opportunities to learn a number of career skills such as writing grant proposals, teaching students, writing articles for publication and communication skills.
The successful candidate for this position is expected to have earned a Ph.D. in plasma engineering, nuclear engineering, electrical engineering, mechanical engineering, material science, physics, or a related area before the date of joining. Research experiences in any or all of the following fields are a plus:

– Fusion-Energy-Related Experiments
– Plasma Surface Modification
– Plasma Diagnostics (QCM, ESA, OES, Laser based diagnostics)
– Plasma Modeling
– Plasma Processing Applications
– Plasma Synthesis of Materials
– Material Characterization Tools (SEM, TEM, AFM, Profilometer, Ellipsometer, XPS, AES, TOFSIMS etc.)
– Atmospheric Pressure Plasmas

The post-doctoral research associate will have an opportunity to be involved in all of the above areas and will help grow the group within these and related areas. To apply for this position please send cover letter, CV/resume, and contact information for 3 references to Andrew Groll (groll1@illinois.edu).

Salary: $46,000 (or competitive and commensurate with experience)
Start date: September 2013
Expected duration of the position: 1-2 years

Contact information for this position: Prof. David Ruzic, druzic@illinois.edu or Andrew Groll, groll1@illinois.edu.

A downloadable copy is located below:

Download

Summer Fun and Education at CPMI!

June 20, 2013

Every year, students from various high schools and middle schools come to visit the University of Illinois. Many of these students participate the World Wide Youth in Science and Engineering (WYSE) camps offered by the Engineering College. During WYSE, students explore multiple different engineering fields for tours of the facilities, demos, and experiments. When students visit the Nuclear engineering department, CPMI presents the fundamentals of plasma physics by displaying various vacuum chambers, crushing cans, and launching copper rings using its newly created coil gun.

Updated Alumni List!

June 20, 2013

The quite important alumni list has been updated including all Master’s and Ph.D. students as well as their respective theses. Take a look. Contact information coming soon!