CN104764421A - Method for rapidly determining thickness of energy reduction piece of heavy ion accelerator single particle test - Google Patents

Abstract

The invention relates to a method for rapidly determining the thickness of an energy reduction piece of a heavy ion accelerator single particle test. The method comprises the steps that a base range of a heavy ion in silicon is determined according to the type of the heavy ion of the accelerator and initial energy; the range of a corresponding heavy ion in the silicon is determined according to the type of the heavy ion of the accelerator and a requested heavy ion LET value; according to the range of the heavy ion corresponding to the base range of the heavy ion and the requested heavy ion LET value in the silicon, the thickness of shielding materials is determined when the material of the energy reduction piece is the silicon; a thickness conversion coefficient between the thickness of the silicon materials and the thickness of the energy reduction piece is determined; the thickness of the silicon materials is converted into the thickness of the energy reduction piece. By means of the method for rapidly determining the thickness of the energy reduction piece of the heavy ion accelerator single particle test, the thickness of the energy reduction piece can be determined rapidly, the cost is reduced, and the efficiency is improved.

Description

A kind of heavy ion accelerator single particle experiment falls can sheet thickness fast determination method

Technical field

The present invention relates to a kind of heavy ion accelerator single particle experiment and fall energy sheet thickness fast determination method, belong to space flight single particle effect technical field.

Background technology

Along with satellite earth observation level of resolution requires more and more higher, information processing capacity is increasing, tackles this requirement, satellite have employed extensive logical device, as FPGA, DSP etc.The impact that these extensive logical devices are subject to Energetic particle produces the single particle effects such as single-particle inversion (SEU), locking single particle (SEL), spacecraft normal reliable can be affected run, with device single particle effect parameter for input, single particle effect protection Design must be carried out.

The parameter testing of device single particle effect, the checking of device single particle effect protection effect, all need test, and have requirement to the linear energy transfer coefficient (Linear EnergyTransfer, LET) of heavy ion on heavy ion accelerator.When carrying out single particle experiment, particularly when single-particle protection Design compliance test result, the LET value of heavy ion need reach the numerical value that technical manual or technology contract require.The LET value of heavy ion is relevant with target material, and because current most device is substrate with silicon materials, therefore in single particle experiment, heavy ion LET value refers to the LET value in silicon materials.

Generally, the type of the heavy ion that heavy ion cyclotron obtains and zero energy are determined, the initial LET value of the heavy ion obtained thus is also a determined value; In most cases, this initial LET value does not meet technical requirement, and needing to add certain thickness falling between the outlet of accelerator heavy ion with device under test can sheet, reduces the energy of heavy ion, thus makes the heavy ion LET value of sheet to meet the demands through falling.

Fall and can two parameters be had to need to determine by sheet: one is the material falling energy sheet, and another is the thickness falling energy sheet.The material falling energy sheet can be selected according to actual conditions, generally, selects the metal material of light atom ordinal number.

Classic method is when determining to fall energy sheet thickness, be generally with heavy ion type, heavy ion energy, fall energy sheet material type, fall energy sheet thickness for input parameter, adopt the method that PARTICLE TRANSPORT FROM is analyzed, simulation analysis heavy ion can energy after sheet through falling, then according to the LET value of this energy spectrometer heavy ion in silicon materials; Analyze, attempting different falling can sheet thickness, until heavy ion LET value meets the demands.

Classic method addresses this problem, and need the thickness for falling energy sheet to attempt in a large number, simulation analysis work has certain blindness, and workload is large, and efficiency is low, and the time is long.

Summary of the invention

The technology of the present invention is dealt with problems and is: for the deficiencies in the prior art, propose a kind of can sheet fast determination method for falling of heavy ion accelerator single particle effect test, the present invention can be equivalent to silicon materials by sheet by falling, with the heavy ion LET value required for target, according to the LET value of dissimilar heavy ion in silicon materials and the related table of range R and ENERGY E, determine the thickness falling energy sheet fast.

Solution of the present invention is:

Energy sheet thickness fast determination method falls in a kind of heavy ion accelerator single particle experiment, comprises step as follows:

(1) according to accelerator heavy ion type and zero energy E ₀, determine the initial range R of heavy ion in silicon ₀;

(2) according to the heavy ion LET value of accelerator heavy ion type and requirement, the corresponding range R of heavy ion in silicon is determined;

(3) according to the initial range R of heavy ion in step (1) ₀and the heavy ion range R in silicon corresponding with requiring heavy ion LET value in step (2), determine when fall can sheet material be silicon time, the thickness d of shielding material _si; Computing formula is:

d _Si＝R ₀-R

Wherein, d _sithe thickness of energy sheet falls when being silicon for falling energy sheet material, R ₀be the initial range of heavy ion in silicon materials, R is the heavy ion range in silicon corresponding with the heavy ion LET value required;

(4) silicon materials thickness d is determined _siwith the thickness conversion coefficient k falling energy sheet thickness d;

Account form is as follows:

$k=\frac{{\mathrm{\ρ}}_{\mathrm{Si}}\frac{Z_{\mathrm{Si}}}{A_{\mathrm{Si}}}}{\mathrm{\ρ}\frac{Z}{A}}$

Wherein, k is silicon materials and the thickness conversion coefficient falling energy sheet material, ρ _sithe density of silicon materials, Z _sithe atomic number of silicon materials, A _sithe atomic weight of silicon materials, ρ be fall can sheet institute adopt the density of material, Z be fall can sheet adopt the atomic number of material, A be fall energy sheet adopt the atomic weight of material;

(5) by the thickness d of silicon materials _sibe converted into the thickness d of falling energy sheet;

Conversion formula is:

d＝k·d _Si

Wherein, d is the thickness falling energy sheet, d _sibe the thickness of silicon materials, k is silicon materials and the thickness conversion coefficient falling the material that energy sheet adopts.

The present invention's beneficial effect is compared with the conventional method:

(1) the present invention does not need to be calculated by the particle transport theory of complexity and a large amount of simulation calculation that fall can sheet thickness, the present invention is undertaken by adopting the mode of resolving, and do not need a large amount of trial work, only need simple analytical Calculation can determine fast to fall energy sheet thickness, time is short, efficiency is high, greatly provides cost savings.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of the inventive method.

Embodiment

Below in conjunction with accompanying drawing, principle of work of the present invention and the course of work are explained and explained.

As shown in Figure 1, energy sheet thickness fast determination method falls in a kind of heavy ion accelerator single particle experiment of the present invention, comprises step as follows:

(1) according to accelerator heavy ion type and zero energy E ₀, determine the initial range R of heavy ion in silicon ₀;

The heavy ion of certain type, its ENERGY E and zero energy E ₀, range R in silicon and initial range R ₀, there is corresponding relation in LET value in silicon, obtain by SRIM software.For nickel ion (Ni-58), employing SRIM can obtain result below.

The corresponding relation of the ENERGY E of table 1 nickel ion, range R and LET value

Nickel ion ENERGY E (MeV)	LET value (MeVcm 2/mg)	Range R (μm)
			350	25.6	57.4
375	25.0	61.7
			400	24.3	66.0
450	23.1	75.1
			500	22.0	84.7
550	20.9	94.8
			600	20.0	105.3
650	19.2	116.3
			700	18.4	127.8
800	17.0	152.1
			900	15.9	178.3
1000	14.9	206.3
			1500	11.6	371.8
2000	9.5	577.6
			2500	8.2	822.3
3000	7.2	1100.0
			3500	6.4	1420.0
4000	5.9	1770.0
			4500	5.4	2160.0
5000	5.0	2570.0
			5500	4.7	3020.0
6000	4.4	3500.0
			6500	4.1	4010.0
7000	3.9	4540.0
			8000	3.6	5690.0
9000	3.3	6950.0
			10000	3.1	8300.0

The zero energy of the nickel ion that such as heavy ion accelerator obtains is 4000MeV, can see from upper table data, and now the LET value of heavy ion in silicon is 5.9MeVcm ²/ mg, the range R in silicon ₀it is 1770 μm.

The initial LET value of nickel ion of 4000MeV is 5.9MeVcm ²/ mg, when the heavy ion LET value required is not this numerical value, the heavy ion LET value as required is 15MeVcm ²/ mg, must adopt certain measure to reduce nickel ion energy thus improve LET value.(2) according to the heavy ion LET value of accelerator heavy ion type and requirement, the corresponding range R of heavy ion in silicon is determined;

Adopt the data of table 1, obtain the heavy ion range R in silicon corresponding with the heavy ion LET value required.

The nickel ion LET value such as required is 15MeVcm ²/ mg, when nickel ion energy is 900MeV as can be seen from Table 1, corresponding LET value is 15.9MeVcm ²/ mg, corresponding range is 178.3 μm, and during nickel ion 1000MeV, corresponding LET value is 14.9MeVcm ²/ mg, corresponding range is 206.3 μm, carries out linear interpolation to these two data, can obtain LET value for 15MeVcm ²during/mg, corresponding nickel ion range is 203.5 μm.

Resulting in the heavy ion LET value of requirement for 15MeVcm ²during/mg, corresponding heavy ion range R is 203.5 μm.

(3) according to the initial range R of heavy ion in step (1) ₀and the heavy ion range R in silicon corresponding with requiring heavy ion LET value in step (2), determine when fall can sheet material be silicon time, the thickness d of shielding material _si; Computing formula is:

d _Si＝R ₀-R

Wherein, d _sithe thickness of energy sheet falls when being silicon for falling energy sheet material, R ₀be the initial range of heavy ion in silicon materials, R is the heavy ion range in silicon corresponding with the heavy ion LET value required;

According to the result of step (1) and step (2), can obtain falling can sheet material when being silicon, and thickness is:

d _Si＝1770-203.5＝1566.5(μm)

(4) silicon materials thickness d is determined _siwith the thickness conversion coefficient k falling energy sheet thickness d;

Account form is as follows:

$k=\frac{{\mathrm{\ρ}}_{\mathrm{Si}}\frac{Z_{\mathrm{Si}}}{A_{\mathrm{Si}}}}{\mathrm{\ρ}\frac{Z}{A}}$

Wherein, k is silicon materials and the thickness conversion coefficient falling energy sheet material, ρ _sithe density of silicon materials, Z _sithe atomic number of silicon materials, A _sithe atomic weight of silicon materials, ρ be fall can sheet institute adopt the density of material, Z be fall can sheet adopt the atomic number of material, A be fall energy sheet adopt the atomic weight of material;

For aluminum as falling energy sheet, the density of aluminium is 2.7g/cm ³, the atomic number of aluminium is 13, and the atomic weight of aluminium is 27, then the thickness conversion coefficient of silicon materials and aluminum is:

$k=\frac{{\mathrm{\ρ}}_{\mathrm{Si}}\frac{Z_{\mathrm{Si}}}{A_{\mathrm{Si}}}}{\mathrm{\ρ}\frac{Z}{A}}=\frac{2.33\×\frac{14}{28}}{2.7\×\frac{13}{27}}=0.90$

(5) by the thickness d of silicon materials _sibe converted into the thickness d of falling energy sheet;

Conversion formula is:

d＝k·d _Si

Wherein, d is the thickness falling energy sheet, d _sibe the thickness of silicon materials, k is silicon materials and the thickness conversion coefficient falling the material that energy sheet adopts.

Do for aluminum that fall can sheet, the thickness conversion coefficient k of the silicon materials that the 4th step obtains and aluminum is 0.9, according to thickness conversion coefficient, the 3rd step can be obtained falling energy sheet material thickness d when being silicon _sibe converted to that fall can the thickness d of sheet when being aluminum:

d＝k·d _Si＝0.9×1566.5＝1409.9(μm)

Resulting in when selecting aluminium as when falling energy sheet material, desired thickness is 1409.9 μm.This shows that needs add thickness between the outlet of accelerator heavy ion with device is that the aluminum of 1409.9 μm falls can sheet, just can obtain 15MeVcm at device place ²the heavy ion LET value of/mg, thus meet the demands.

The undocumented part of the present invention is known to the skilled person general knowledge.

Claims (1)

1. an energy sheet thickness fast determination method falls in heavy ion accelerator single particle experiment, it is characterized in that comprising step as follows:

(1) according to accelerator heavy ion type and zero energy E ₀, determine the initial range R of heavy ion in silicon ₀;

(2) according to the heavy ion LET value of accelerator heavy ion type and requirement, the corresponding range R of heavy ion in silicon is determined;

(3) according to the initial range R of heavy ion in step (1) ₀and the heavy ion range R in silicon corresponding with requiring heavy ion LET value in step (2), determine when fall can sheet material be silicon time, the thickness d of shielding material _si; Computing formula is:

d _Si＝R ₀-R

Wherein, d _sithe thickness of energy sheet falls when being silicon for falling energy sheet material, R ₀be the initial range of heavy ion in silicon materials, R is the heavy ion range in silicon corresponding with the heavy ion LET value required;

(4) silicon materials thickness d is determined _siwith the thickness conversion coefficient k falling energy sheet thickness d;

Account form is as follows:

$k=\frac{{\mathrm{\ρ}}_{\mathrm{Si}}\frac{Z_{\mathrm{Si}}}{A_{\mathrm{Si}}}}{\mathrm{\ρ}\frac{Z}{A}}$

Wherein, k is silicon materials and the thickness conversion coefficient falling energy sheet material, ρ _sithe density of silicon materials, Z _sithe atomic number of silicon materials, A _sithe atomic weight of silicon materials, ρ be fall can sheet institute adopt the density of material, Z be fall can sheet adopt the atomic number of material, A be fall energy sheet adopt the atomic weight of material;

(5) by the thickness d of silicon materials _sibe converted into the thickness d of falling energy sheet;

Conversion formula is:

d＝k·d _Si

Wherein, d is the thickness falling energy sheet, d _sibe the thickness of silicon materials, k is silicon materials and the thickness conversion coefficient falling the material that energy sheet adopts.