Electron-impact collisions with Be+

Yuri Ralchenko and Dipti National Institute of Standards and Technology Gaithersburg, MD, USA

IAEA, Vienna, Austria June 6, 2019

IAEA, June 6, 2019

IAEA, June 6, 2019

Followup to the June 2015 meeting

IAEA, June 6, 2019

Be I fits: excitation: CCC+BSR

• Dipole-allowed

• Dipole-forbidden

• Spin-forbidden

Correct asymptotic and threshold behavior

IAEA, June 6, 2019

IAEA, June 6, 2019

Structure calculations: line strengths

𝐴 ∝ ∆ 𝐸3 ∙ 𝑆

IAEA, June 6, 2019

IAEA, June 6, 2019Examples of fits

ioniz

da and df

sf

RC

IAEA, June 6, 2019

Fit coefficients

IAEA, June 6, 2019

NIFS database contents: exc+ion

IAEA, June 6, 2019

Recent important publications (n≤4)

• 1997: Bartschat and Bray ▫ RMPS (26 states), CCC, n ●exc, ion, CS

• 2003: Ballance et al ▫ DW, R-matrix, RMPS (41 states), TDCC ●exc, ion, CS, RC

• 2011: Liang and Badnell ▫ ICFT R-matrix ●Exc, effective collision strengths

IAEA, June 6, 2019

IAEA, June 6, 2019

R-matrix (14 st) RMPS (41 st) CCC TDCC

IAEA, June 6, 2019

IAEA, June 6, 2019

Plan

• D. Fursa (Curtin) agreed to perform new calculations with CCC

• Approach C. Ballance, J. Colgan,... for the older data • Evaluate radiative parameters (should be very

straightforward, Li-like ion) • Fit the cross sections (collision strengths) ▫ Similar formulas but without (x-1) factor

• Publish in ADNDT