Advancing Vacuum Technology in Particle Accelerator Research
BRANDTECH® Scientific recently worked with the Arizona State University Eyring Materials Center Ion Beam Analysis of Materials (IBeAM) lab to support an upgrade to their vacuum equipment. Mark Mangus, Research Specialist Principal at the Eyring Materials Center works with students and industry partners in the IBeAM lab to train them on the use of the equipment, data reduction, and is tasked with maintaining the equipment. One upgrade Mangus wanted to evaluate was identifying a lower-maintenance roughing pump for their particle accelerator. A new roughing pump would need to provide reliable, stable, and low vibration vacuum to achieve optimal vacuum conditions for particle accelerator experiments. Mangus evaluated a VACUUBRAND® VACUU∙PURE® 10 screw pump as an alternative to oil-sealed rotary vane pumps and found that the VACUU∙PURE 10 oil-free pump offered comparable performance to traditional rotary vane pumps they were using, without the need for oil changes and rebuilds. This review investigates the technical details and benefits of using the VACUU∙PURE 10 vacuum pump in ASU’s particle accelerator.
General Requirements for ASU High Vacuum Applications
Reliability: Minimizing downtime is crucial for maximizing experimental productivity and reducing maintenance costs.
Deep, Stable Vacuum: The particle accelerator requires a stable 10-3 torr vacuum from the roughing pump to achieve consistent vacuum levels as low as 10-9 torr with the turbo pump.
Low Vibration: Minimizing vibration ensures the stability of sensitive equipment and improves the reproducibility of experimental data.
Particle Accelerator Application Details: The particle accelerator in the IBeAM lab is a 1.7 MeV Tandetron Ion Accelerator. It facilitates various experiments under the umbrellas of ion beam analysis (IBA) and ion beam modification of materials (IBMM). Some of the unique applications include:
- Chemical composition analysis of current and next generation thin films for semiconductor applications.
- Particle (ion) induced x-ray emission (PIXE) for chemical analysis of cultural heritage artifacts including Roman-era death masks, ancient pottery and statues and metals used in ancient weapons with end goals being authentication and determining ancient trade routes.
- Particle (ion) induced gamma emission (PIGE) for isotope analysis of Lithium and other elements used in energy applications.
The particle accelerator’s analytical chamber operates in the high vacuum range (10-7 to 10-8 torr). The load lock, used to transition samples and equipment into the analytical chamber, is pumped down to a relative foreline pressure of approximately 5 x 10-2 using the roughing pump. The turbo pump is then engaged to bring the load lock down to 10-6 – 10-7 torr. The turbo pump used is rated for up to 260 l/s. An oil-sealed rotary vane pump with a rated pumping speed of 14.2 m3 /hr. and an ultimate vacuum of 1.5 x 10-3 torr had been used until recently. The rotary vane pump was replaced with the VACUU∙PURE 10 oil-free screw pump to assess the feasibility of a low-maintenance and oil-free roughing pump. The VACUU∙PURE 10 has a rated pumping speed of 10 m3 /hr. and an ultimate vacuum of 3.8 x 10-3 torr. The process of evacuating the load lock from atmospheric pressure to the relative foreline pressure of approximately 5 x 10-2 took roughly 6 minutes with the rotary vane pump. A comparable pump down time was achieved using the VACUU∙PURE 10 oil-free screw pump. When the gate valve isolating the load lock from the analytic chamber is opened, a pressure rise of less than one order of magnitude has been observed when the VACUU∙PURE pump has been used as the roughing pump. Mangus also briefly considered scroll pumps as an alternative to the incumbent rotary vane pumps. However, a cursory evaluation of their relative price, maintenance requirements, and ultimate revealed that the VACUU∙PURE 10 oil-free screw pump and the incumbent rotary vane pump both offered superior value over the scroll pump. Ultimately, Mangus determined that the VACUU∙PURE 10 oil-free screw pump provides comparable pump performance with the added benefit of an ultra-low maintenance roughing pump. Rotary vane pumps require frequent oil changes and Mangus was sending his rotary vane pumps out for rebuild roughly every two years, demanding significant time and resources. This also has the effect of limiting the time that the particle accelerator can be used for research by students and ASU’s industry partners.
Conclusion: The integration of the VACUU·PURE 10 pump has met the stringent requirements of reliability, stability, and low vibration. By offering comparable performance to traditional pumps while eliminating the need for oil changes, the VACUU·PURE 10 has enabled more efficient research processes and enhanced collaboration opportunities with students and industry partners.
BRANDTECH Scientific offers VACUUBRAND vacuum technology in the US and Canada, through your lab products distributor or direct at brandtech.com. Our sales and support team are available to determine what vacuum solution fits your needs- contact BRANDTECH today to upgrade your lab vacuum with quality VACUUBRAND vacuum pumps.
RBS Endstation with VACUU∙PURE 10. Photo courtesy of Mark Mangus – ASU IBeAM Laboratory