Heavy-ion cocktails available at RADEF
RADEF specialty is high penetration heavy ion cocktail beams which are used for commercial services and academic research. The beams are called ion cocktails, because they are mixture of ions with almost the same mass to charge ratio. This property allows a fast swap between ion species, which is especially valuable in the study of single event effects in semiconductor devices. Even the beams are called cocktail the ions are taken to the target separately one ion species at the time.
Four heavy ion cocktails up to Au ion with the energies of 9.3 MeV/n, 10 MeV/n, 16.3 MeV/n and 22 MeV/n are available at RADEF. Heavy ion irradiations can be done in vacuum or in air mode. The basic properties of the cocktails are given in Tables 1-4. Development of LET values of ions vs. range in silicon are estimated based on the SRIM-2013 code in Figures 1-6.
Basic properties of cocktails available at RADEF
Table 1: 9.3 MeV/n ion cocktail. N, Fe, Kr and Xe are in the same cocktail and the changing time between them is less than 15 min. The same is between Ne and Ar, which are in another cocktail. Changing time between ions in different cocktails ((N, Fe, Kr, Xe)<->(Ne, Ar)) is about 1 hour. This is our old cocktail which is still available, but we recommend to use 16.3 MeV/n cocktail instead if possible.
Table 2: 10 MeV/n ion cocktail. Changing time from ion to ion is about 15 min. Changing time between this and 16.3 Me/n cocktail is about 30 min.
Table 3: 16.3 MeV/u ion cocktail. All the ions are in the same cocktail and the changing time from ion to ion is less than 15 min. Changing time between this and 10 Me/n cocktail is about 30 min.
Table 4: 22 MeV/u ion cocktail. Changing time between ion to ion is about 15 min.
9.3 MeV/n cocktail
LET values of 9.3 MeV/n cocktail ions as a function of depth in silicon in vacuum mode (SRIM 2013) in shown in Figure 2. Vertical dash lines show the effective DUT surface positions when 25, 50 and 75 µm of Kapton foil is added front of the DUT.
Figure 1. LET curves of 9.3 MeV/n cocktail ions in silicon in vacuum mode. Vertical dash lines show the effective DUT surface positions when 25, 50 and 75 µm of Kapton is added front of the DUT
LET values of 9.3 MeV/n cocktail ions as a function of depth in silicon in air mode (SRIM 2013) are shown in Figure 2. Due to the beam exit window and 5-10 mm of air, DUT surface is effectively on about 22 µm line. Vertical dash lines show the effective DUT surface positions when 25 and 50 µm of Kapton foil is added between the beam window and the DUT.
Figure 2. LET curves of 9.3 MeV/u cocktail ions in silicon in air mode. Vertical dash lines show the effective DUT surface positions when 25 and 50 µm of Kapton foil is added between the beam window and the DUT.
10 MeV/n cocktail
LET values of 10 MeV/n cocktail ions as a function of depth in silicon in vacuum mode (SRIM 2013) is shown in Figure 3. Vertical dash lines show the effective DUT surface positions when 25, 50 and 75 µm of Kapton foil is added front of the DUT.
Figure 3. LET curves of 10 MeV/u cocktail ions in silicon from Ar to Au in upper and from B to Ar in bottom figure for vacuum mode experiments. Vertical dash lines show the effective DUT surface positions when 25, 50 and 75 µm of Kapton foil is added front of the DUT.
16.3 MeV/n cocktail
LET values of 16.3 MeV/n cocktail ions as a function of depth in silicon in vacuum mode are shown in Figure 4 (SRIM 2013). Vertical dash lines show the effective DUT surface positions when 25, 50, 75 and 100 µm of Kapton foil is added front of the DUT.
Figure 4. LET curves of 16.3 MeV/u cocktail ions in silicon in vacuum mode (SRIM2013). Vertical dash lines show the effective DUT surface positions when 25, 50, 75 and 100 µm of Kapton is added front of the DUT.
LET values of 16.3 MeV/n cocktail ions as a function of depth in silicon in air mode are shown in Figure 5 (SRIM 2013). Due to the beam exit window and 5-10 mm of air DUT surface is effectively on about 22 µm line. Vertical dash lines show the effective DUT surface positions when 25, 50, 75 and 100 µm of Kapton foil is added between the beam window and the DUT.
Figure 5. LET curves of 16.3 MeV/u cocktail ions in silicon in air mode. Vertical dash lines show the effective DUT surface positions when 25, 50, 75 an 100 µm of Kapton is added between the beam window and the DUT.
22 MeV/n cocktail
LET values of 22 MeV/n cocktail ions as a function of depth in silicon in vacuum mode (SRIM 2013) is shown in Figure 6.
Figure 6. LET curves of 20 MeV/u cocktail ions in silicon in vacuum mode (SRIM 2013).
ECIF (European Component Irradiation Facities) Cocktail Calculator, which can be use to estimate LET values of different ions in different materials can be found .
Contact information:
Email: heikki.i.kettunen@jyu.fi