Materials for Bright Beams Workshop 2025

Contribution List

35. Welcome

J. Ritchie Patterson

7/16/25, 8:45 AM

1. Workshop charge

Lance Cooley (Applied Superconductivity Center, NHMFL, Florida State University)

7/16/25, 8:50 AM

8. Photocathode Opening Talks

7/16/25, 9:05 AM

9. Superconducting RF Cavities Opening Talks

7/16/25, 10:45 AM

34. Perspectives from DOE OHEP

Derun Li (DOE OHEP)

7/16/25, 12:00 PM

11. High Gradient Opening Talks

7/16/25, 1:30 PM

29. Photocathodes Session 1

7/16/25, 3:15 PM

24. Superconducting RF Cavitiy Session 1

7/17/25, 8:00 AM

28. High-Gradient Structures Session 1

7/17/25, 10:15 AM

12. Photocathode Session 2

7/17/25, 1:15 PM

13. Superconducting RF Cavity Session 2

7/17/25, 3:30 PM

32. Industry Blitz

7/17/25, 5:15 PM

14. Dinner and Poster Session - Baker Portico (Postdoc and Grad Student Poster Session)

7/17/25, 6:05 PM

27. High-Gradient Structures Session 2

7/18/25, 8:30 AM

16. Summary Talks

7/18/25, 10:40 AM

18. Facility Tours

7/18/25, 12:55 PM

2. Accelerator Materials Session

3. Accelerator Materials Talk

4. Accelerator Materials Talk

5. Accelerator Materials Talk

6. Accelerator Materials Talk

7. Accelerator Materials Talk

19. CBETA Tour

38. Development of a Plasma-Enhanced Chemical Vapor Deposition System for High-Performance SRF Cavities and Thin Film Studies

Gabriel Gaitan

Next-generation, thin-film surfaces employing Nb3Sn, NbN, NbTiN, or other compound superconductors are essential for reaching enhanced RF performance levels in SRF cavities. However, optimized, advanced deposition processes are required to enable high-quality films of such materials on large and complex-shaped cavities. For this purpose, Cornell University developed and commissioned a...

22. Electron Microscopes Tour

20. Hercules and Medusa Tour

37. High power RF testing of high-temperature superconductors

Ankur Dhar (SLAC National Accelerator Lab)

Superconducting materials such as niobium have been extremely useful for accelerator technology but require low temperature operation ~2 K. The development of high temperature superconductors (HTS) is promising due to their operating temperatures being closer to that of liquid nitrogen ~77 K. This work aims to determine the high-power RF performance of these materials at X-band (11.424 GHz)....

43. Identifying the connections between grain growth and flux expulsion in low RRR niobium SRF cavities

Katrina Howard (University of Chicago)

The SRF community has shown that high temperature annealing can improve the flux expulsion of niobium cavities during cooldown. The required temperature will vary between cavities and different batches of material, typically around 800 C and up to 1000 C. However, for niobium with a low residual resistance ratio (RRR), even 1000 C is not enough to improve its poor flux expulsion. The purpose...

31. Industry Blitz

44. Investigating Dirac semimetal cadmium arsenide as a potential low-MTE photocathode

Truman Idso (Arizona State University)

We report on the quantum efficiency (QE) and mean transverse energy (MTE) of photoemitted electrons from cadmium arsenide $(\mathrm{Cd_3As_2})$, a three-dimensional Dirac semimetal (3D DSM) of interest for photocathode applications due to its unique electronic band structure, characterized by a 3D linear dispersion relation at the Fermi energy. Samples were synthesized at the National...

21. Low Emittance Beamline Tour

40. Measurements of Stability Diagrams in the IOTA Ring at Fermilab

MaryKate Bossard

Nonlinear focusing elements enhance the stability of particle beams in high-energy colliders via Landau Damping, a phenomenon that acts through the tune spread these elements introduce. This experiment at Fermilab's Integrable Optics Test Accelerator (IOTA) aims to investigate the influence of nonlinear focusing elements on transverse beam stability by employing a novel method to directly...

39. Molecular beam epitaxial growth of sodium antimonide photocathodes

Elena Echeverria

The Center for Bright Beams (CBB) at Cornell University has been developing techniques to grow single-crystal photocathodes for electron sources using molecular beam epitaxy (MBE). As a result, the first single-crystal Cs3Sb photocathode was produced, which has shown high quantum efficiency and is expected to have a low mean transverse energy (MTE). Now, other alkali materials are being...

17. Photocathodes Session

30. Photocathodes Session

23. SRF Facility Tour

25. SRF Tour

42. Status of the CYBORG beamline at UCLA: First Room Temperature Photoelectrons, soon available at 80 K!

Fabio Bosco

The intrinsic emittance obtained from radio-frequency (RF) photoinjectors is notably reduced by increasing the launch field at the cathode. Moreover, cryogenic RF guns offer the possibility of producing stronger fields, due to the higher bulk conductivity and lower breakdown rate, while reducing the mean transverse energy (MTE) of near-threshold photo electrons. Such devices thus constitute an...

26. Summary Talks 30 minutes each, at least

41. Synthesis of ordered Na-K-Sb photocathodes with oxygen-enhanced quantum efficiency

Abigail Flint

Alkali antimonide photocathodes are recognized for their efficacy as photoemissive materials in electron sources. This study investigates the fabrication of ordered films of sodium potassium antimonide via Molecular-Beam Epitaxy (MBE) and the impact of oxygen on their performance at the PHOtocathode Epitaxy Beam Experiments (PHOEBE) laboratory within the Center for Bright Beams (CBB) at...

33. Workshop Summary