Internship Scanning Electron Microscopy Jobs in California

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

Castelion is seeking a detail-oriented Scanning Electron Microscopy (SEM) Characterization Technician to support the TPS material development program. This role will be responsible for specimen preparation, SEM operation, and microstructural characterization of advanced aerospace materials.

The successful candidate will work closely with the Materials & Processes team to generate high-quality microscopy data in support of material development, qualification, and production.

• Prepare specimens for SEM analysis using standard metallographic preparation techniques.
• Operate SEM equipment to characterize metallic, ceramic, polymeric, and composite materials.
• Perform microstructural characterization including coating dimensional measurements and morphology.
• Generate microscopy reports and maintain organized image and data archives.
• Coordinate characterization activities with the Materials & Processes team.
• Maintain SEM, polishers and all associated laboratory equipment and ensure safe laboratory practices.

• Associate degree, technical certification, or equivalent laboratory experience in materials science, metallurgy, engineering technology, or a related field.

• Experience with metallographic specimen preparation and microscopy techniques.
• Experience operating scanning electron microscopy (SEM) equipment is preferred.
• Strong attention to detail and excellent documentation skills.
• Ability to work effectively in a laboratory environment.

• Employee Equity: Meaningful equity for all full-time employees - share value has increased 150x in three years
• Personal Time Off: Four (4) weeks of paid time off to unplug, reset, and come back sharp-velocity matters, burnout doesn't
• Company Paid Holidays: Ten (10) company paid holidays
• Medical: We offer plans at 100% employee covered and 80% of dependent coverage
• Dental & Vision: We cover 90% employees and 80% for dependents to ensure you and your family have access to quality preventive and ongoing care
• FSA/HSA: To support long-term health and financial resilience, we offer FSA and HSA options that allow employees to set aside pre-tax dollars for eligible medical and dependent care expenses
• Retirement: 401k plan offered to support long term financial growth along side high-impact, high-velocity work
• Paid Parental Leave: We support growing families with meaningful time to bond and recover. Birthing parents are eligible for up to 10 weeks of paid leave, while non-birthing parents may take up to 4 weeks of paid leave. This time can be used for pre-natal care, pregnancy, childbirth, and related medical needs-ensuring every parent has the support they need during this important life moment.8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees
• Meals & Catering: Frequently catered lunches and team meals, plus company-covered meals when extra time or effort is required
• Snacks & Beverages: Fully stocked kitchen with unlimited snacks and drinks to keep you fueled throughout the day
• Performance & Fitness: $100 monthly fitness stipend to support peak performance and health, both inside and outside of work
• EV Charging: Onsite electric vehicle charging available for employees

• Must be willing to work extended hours and/or weekends as needed
• Must be able to travel up to 30%
• Must be able to lift more than 50lbs

To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.

This position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply. Failure to obtain or maintain any required clearance or authorization may result in reassignment, leave, or separation from employment, consistent with business needs and applicable law.

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice.