People

Principal Investigator 

Oliver Gessner, PhD


Group Leader and Leader of the Atomic, Molecular and Optical Sciences (AMOS) Program at Berkeley Lab

Email: OGessner@lbl.gov

Additional Information & CV

Google Scholar


Postdoctoral Fellows

Dr. Sahan Perera


Ph.D. Chemistry 2019, Univ of Saskatchewan   

MSc. Univ of Saskatchewan

Project: Time-resolved X-ray photoelectron spectroscopy of light harvesting systems 

Hobbies: Nature photography, board games, and cricket 

Email: SahanNeelakanniMudiyanselage@lbl.gov 

Dr. Kin Fung Lai


Ph.D. Physics 2022, Vrije Universiteit Amsterdam   

MSc. Chinese University of Hong Kong

Project: X-ray transient absorption spectroscopy of chemical dynamics

Email: KFLai@lbl.gov

Graduate Students 

Lars Hoffman, 3rd year Ph.D. Candidate


B.S. Chemistry 2016, Freie Universität Berlin

Project: X-ray transient absorption spectroscopy and ultrafast electron diffraction

Hobbies: Running, hiking, gaming, and esports

Email: larshoffmann@lbl.gov 

Zachery Donnellan, 2nd year Ph.D. Candidate


B.S. Chemistry 2020, West Virginia University 

Project: Time-resolved X-ray photoelectron spectroscopy of light harvesting systems 

Hobbies: Climbing, hiking, video games, reality tv

Email: zachery_donnellan@berkeley.edu

Undergraduate Students

Elham Ghanem


B.S. Chemistry expected Spring 2023, Cal State Univ., East Bay

Project: X-ray transient absorption spectroscopy and ultrafast electron diffraction

Hobbies: Tennis, watching movies

Email: eghanem@lbl.gov 

Christian Claudio


UC Berkeley and Lawrence Berkeley National Laboratory

Project: Spectroscopy and and imaging of dynamics in helium nanodroplets

Email: cclaudio@lbl.gov 

Recent Alumni 

Dr. Catherine Saladrigas


Ph.D. 2022, UC Berkeley and Lawrence Berkeley National Laboratory

B.S. Physics 2016, MIT

Project: Spectroscopy and and imaging of dynamics in helium nanodroplets

Hobbies: Hiking, kayaking, hotsprings, piano, gluten free cooking 

Email: catherine_saladrigas@berkeley.edu 

Dr. Matthew Fraund


Ph.D. University of the Pacific

B.S. Chemistry 2012, UC Berkeley

Project: Time-resolved X-ray photoelectron spectroscopy of light harvesting systems 

Hobbies: Cooking, video games, and tinkering

Email: mfraund@lbl.gov

Chuying Huang


Ph.D. Student, Northwestern University, Evanston IL, USA

B.S. Chemistry 2022, UC Berkeley

Project: TrXPS, Synchrotron experiments at the ALS, FLASH, SLAC

Hobbies: Travelling

Email: chuyinghuang@lbl.gov

Lida Kaphar


B.S. MCB Neurobiology expected 2023. UC Berkeley 

Project: TrXPS, Synchrotron experiments at the ALS, FLASH, SLAC

Hobbies: Taekwondo, sewing, thrifting 

Email: lkaphar@lbl.gov

Nathan Helvy


B.S. Physics and Applied Math 2021, UC Berkeley

Project: Spectroscopy and dynamics in helium droplets

Hobbies: Reading, robotics, D&D, hiking

Email: nah.pro8@berkeley.edu

Alumni