| name | multipolarity-mixing-ratio |
| description | Use this skill as a reference guide for ENSDF multipolarity (M) and mixing ratio (MR) field notation. Covers E1/M1/E2/M2 designations, shorthand D/Q/O, mixed M1+E2 formatting, symmetric and asymmetric DMR uncertainties, and exact column positions 33-41 (M) and 42-49 (MR). Suitable for writing or reviewing G-record multipolarity fields.
|
| argument-hint | ["multipolarity expression or G-record line"] |
ENSDF Multipolarity and Mixing Ratio Reference
ENSDF 80-column data record and field definitions, structural rules, column positions, and uncertainty notation: .github/agents/ENSDF-Agent.agent.md. Spot-check policy: .github/copilot-instructions.md.
Multipolarity Field Notation
Multipolarity Field (M Field, Columns 33-41)
ENSDF Shorthand Notation: The multipolarity field uses standard abbreviations for electromagnetic transition types.
Single Multipolarities
- D: Dipole transition (electric E1 or magnetic M1)
- Q: Quadrupole transition (electric E2 or magnetic M2)
- O: Octupole transition (electric E3 or magnetic M3)
- E1, E2, E3, ...: Electric multipole transitions (full notation)
- M1, M2, M3, ...: Magnetic multipole transitions (full notation)
Mixed Multipolarities (Combinations)
- D+Q: Mixed dipole and quadrupole (e.g., M1+E2)
- D(+Q): Predominantly dipole with small quadrupole admixture
- (D+Q): Tentative or uncertain mixed transition assignment
- Q+O: Mixed quadrupole and octupole
- M1+E2: Explicit mixed magnetic dipole and electric quadrupole
- M2+E3: Explicit mixed magnetic quadrupole and electric octupole
Critical Formatting Rules
- LEFT-JUSTIFIED in columns 33-41
- Shorthand (D, Q, O) is valid ENSDF notation — do NOT auto-replace with full notation unless specified
- Parentheses indicate uncertainty in multipolarity assignment
- Plus sign (+) indicates mixed transitions with comparable amplitudes
- Full notation (E1, M1, E2, etc.) provides explicit multipole type specification
Examples
Column: 33333333334
3456789012
Format:
Q → Pure quadrupole (shorthand)
D → Pure dipole (shorthand)
E2 → Electric quadrupole (full notation)
M1+E2 → Mixed magnetic dipole + electric quadrupole
D+Q → Mixed dipole + quadrupole (shorthand)
(D+Q) → Tentative mixed dipole + quadrupole
D(+Q) → Predominantly dipole with small quadrupole component
Multipole Mixing Ratios
Mixing Ratio Field (MR Field, Columns 42-49)
Nuclear Physics Definition: Multipole mixing ratios (δ) quantify the degree to which different angular momentum multipoles (like E1 and M2) are mixed in a gamma-ray transition. They represent the amplitude ratio between different electromagnetic transition modes.
Physical Significance
- δ = 0: Pure transition (single multipolarity, e.g., pure E2)
- δ ≠ 0: Mixed transition (multiple multipolarities contributing)
- δ(E2/M1): Ratio of electric quadrupole to magnetic dipole amplitudes
- δ(M1/E2): Ratio of magnetic dipole to electric quadrupole amplitudes
- Angular correlation: Mixing ratios determine gamma-ray angular distributions and correlations
MR Field Examples (Columns 42-49)
+1.23 → δ = +1.23
-0.45 → δ = -0.45
>+2.1 → δ > +2.1
<-0.8 → δ < -0.8
+0.123 → δ = +0.123
-12.3 → δ = -12.3
Multiple Mixing Ratios
Mixing ratios are spin dependent. For transitions from levels with multiple possible spins, list all allowed mixing ratios in a cG comment line.
Example:
35CL cG MR$+0.7 {I+12-2} for J=5/2; -0.40 {I+8-9} for J=9/2
Mixing Ratio Uncertainties (DMR Field, Columns 50-55)
The DMR field supports both symmetric and asymmetric uncertainties.
Symmetric Uncertainties (1-2 Digits)
- Format: Left-justified digits with trailing spaces
Asymmetric Uncertainties (+X-Y Format)
- Format:
+X-Y notation left-justified in 6-character field
- Examples:
+0.5-0.3, +2.1-1.8, +15-8, +0.12-0.09
- Physics context: Common when systematic effects dominate or when theoretical calculations have asymmetric confidence intervals
Special DMR Field Cases
- Limit measurements: Use GT/LT when MR field has a lower/upper limit
Critical Formatting Rules for Mixing Ratios
- Always include sign in MR field (+ or -)
- LEFT-JUSTIFY all values in both MR and DMR fields
- Asymmetric uncertainties use full 6-character DMR field
- No exponential notation — use decimal format only
- Space padding for values shorter than field width
