Checkpoint
which two layer-lines (LL) were used?
Note, there may be multiple acceptable answers to this question. Format: LL (R, Z)
LL (15, 44.5)
LL (15, 16.5)
Hint: LL (???, 122) = 2* LL (15, 44.5) + 2* LL (15, 16.5).
LL(122) is close to meridian, meaning it has to be a very small Bessel order. So, LL(44.5) and LL(16.5) must have different hand. In other word, one is "+" and the other is "-"
What are the possible Bessel order ranges for those two vectors?
LL (15, 44.5)
:
2*π*R*rmax = 2 * 3.14 * (15/1024/0.85) * 151 = 16 Bessel order n ≤ 14
2*π*R*rmin = 2 * 3.14 * (15/1024/0.85) * 80 = 8.6 Bessel order n ≥ 7
LL (15, 16.5):
same range, 7-14
What are the possible symmetries?
What's the correct symmetry (quickly check whether it is in your list)
point group: C1
helical rise: 1.04Å
helical twist: 26.2 degrees