## Recoil Detection Efficiency of the FMA

You specify:
• The projectile Zproj, Aproj, and target Ztar, Atar
• The target thickness (mg/cm2)
• The beam energy (MeV)
• The number of protons, neutrons, and alphas evaporated by the compound nucleus
• The average energy at which they are evaporated (MeV)
• The distance from the target to the FMA (cm)
• The diameter of the FMA aperture (cm)
• The minimum and maximum charge states that the FMA will detect, Qmin and Qmax
The program will simulate 10,000 individual reactions and return:
1. The half angle for the recoil.  (Half of the recoil nuclei are emitted with angles smaller than the half angle.) Half angles are calculated for:
• only particle evaporation of the recoil
• only angular straggling of the recoil in the target1
• the combined effect of particle evaporation and angular straggling

2. Full-width-half-maximum for:
• Recoil energy distribution due only to energy straggling
• Recoil energy distribution due only to particle evaporation
• Recoil energy distribution due to energy straggling and particle evaporation combined

3. Full-width-half-maximum for charge distribution.

4. The efficiency of the FMA for the following:
• Recoil angle (gives a percentage of the recoils with angles less than the maximum detectable angle) for:
• particle evaporation
• angular straggling in the target
• final recoil angle due to both effects
• energy acceptance of the FMA (±20% of the average recoil energy) for:
• Only energy straggling
• Only particle evaporation
• Energy straggling and particle evaporation
• charge state distribution (detects recoils between Qmin and Qmax)
• total efficiency for all of the effects combined
References:
1. J.S. Dionisio, et al., Nuclear Instruments and Methods in Physics Research A282 (1989) 10.
2. V.S. Nikolaev & I.S.Dmetriev, Physics Letters.  A28 (1968) 277.

Fill in the items below and click Calculate

Zproj  Aproj  Ztar  Atar
Beam Energy (MeV)
Target Thickness (mg/cm2 )
Qmin      Qmax
Diameter (cm)      Distance (cm)

Evaporated particles:
protons:    number      energy (MeV)
neutrons:  number      energy (MeV)
alphas:      number      energy (MeV)