Beta Particles Essay, Research Paper

Beta Atoms

Purpose:

I will look into how the field strength varies the warp of Beta Particles.

Preliminary Work

I started my preliminary work because, when I started my measurings utilizing 2 spirals used in experiments to debar negatrons from and electron gun. While proving for the warp of beta atoms, I found that beta radiation was scattered in a really big cone, I can non acquire any readings with sum of beta radiation sprinkling.

So I would hold to build some type of screening for this probe, this is so I can mensurate the warp more easy. The angle at which the beta atoms are being scattered is 48o.

Deciding on the Type of Shielding

I will prove for the best shielding. The best belongingss of the shield will be ; it can be ductile to organize different forms and can be punctured, can halt radiation at a little thickness.

Diagram

Equipment

Strontium 90 beta beginning

GM tubing + counter

Different thickness of different metals

Clamps, foremans and clinch stand to keep the beginning and the stuff being tested.

Method

1. Set-up equipment as in the diagram

2. Record the thickness and the stuff being used.

3. Record 5 readings of the radiation count, and enter them in a tabular array

4. Replace material being tested with different stuff or a different sized stuff.

5. Repeat steps 2 to 4 as required.

Consequences

The background radiation reading is 2, 4, 6, 4, 5, 2. The mean count is 3.8 ( 1dp ) .

Decision

This shows that aluminum stops radiation at 3.5 millimeter, this would be hard to utilize because, this thickness of Aluminium is non ductile and the aluminum is non soft plenty to puncture. Lead can halt radiation at really thin thickness, besides lead is really ductile and is soft plenty to puncture. I will utilize Lead shield at 0.6mm midst, since it is the most abundant thickness available and it is the easiest to organize to any form I want.

Deciding how the shielding can be used.

I want to hold a tight beam of beta atoms in this probe, so I will utilize my cognition on what would be the best manner to screen the beginning.

An unshielded beginning

The beginning is unshielded and has beta atoms distributing out. Angle Theta is the angle which the beta atoms are scattered through. The way of the beta atoms is non a consecutive line, but a curve because the beta atom are deflected by the moles in the air. The points A B are the furthest points where beta ration is detected.

Using a home base shielding

The beta atoms have a smaller angle, that they are being scattered through. Besides if the shield isn t broad plenty the beta atoms that travelled either side of the shielding could do jobs. For illustration, when mensurating the warp of the beta atoms in the electric field, the beta atoms that passes outside of the shield will interfere with observing the warp of the Beta.

Using a cylindrical shielding

The cylindrical shielding produces a smaller angle which the beta atoms are being scattered through than the beginning. But this is excessively broad to for I want to utilize. So I will necessitate a via media of the home base shielding and the cylindrical shielding.

Using Compressive Shielding

This shielding produces the smallest angle for dispersing because the cylinder stops the beta atoms that spread out to the side, the home base stops all the beta atoms that don t base on balls through the hole.

The smaller the hole in the home base shield will impact the counts, because the smaller the hole so greater the figure of beta atoms are absorbed by the shielding. The size of the cylinder does non count as long it has a diameter greater than beginnings width, because the beta atoms will make the same thing as in fig 3.

Making the shielding

To do the shielding, I must be accurate in doing the hole in the home base, I will make this by utilizing a tool designed to do regular indentures. This tool can do holes from 5mm broad to 9mm with intervals of 1mm. In doing the cylindrical shielding, it doesn Ts have to be a cylinder to bring forth the same coveted affect. I will utilize a unit of ammunition metal saloon with which to turn over the lead shielding. The both parts of the shield will be stuck together with tape, because if I piece go damaged or deformed, it can replaced easy.

Measuring the Angle at Which Beta Particles Are Scattered Through With different Diameters of punctures

Diagram

Equipment

Strontium 90 beta beginning

GM Tube

Lead Shielding ( 43.6mm long )

Counter

Method

Note: To do certain that the GM tubing, the puncture and the beginning is in alliance, pull a straight-line with a regulation on the tabular array. Then utilize a set square to acquire the perpendicular perpendicular line. Mark a set distance, this grade will be placed in the Centre of the beginning, GM and the punter along the tabular array. ( Careful with the beginning, approximate the Centre, see safety notes ) .

1. Set-up the equipment as the diagram, step the distance ( 20cm ) with an accurate regulation, saying with home base shield have in a puncture of 5mm to get down with.

2. Take 10 readings per 100s, record these consequences in a tabular array

3. Change the clip base for the counter to 10s and travel the GM tubing along analogue with the shielding. Using the method of test and betterment, find the topographic points where the is a sufficient bead in counts, grade this with a crisp piece of chalk or any other marker.

4. Measure the distance between each point and record the consequences in the tabular array

5. Repeat measure 1 to 4 replacing the home base shielding.

Consequences

The background count had an norm of 28.9 per 100 seconds.

I worked out the angle by utilizing this equation

Tan-1 ( AB/D ) = Angle beta atoms scatter though.

Decision

The graphs demo a additive relationship between the puncture size and distance signifier AB. I would of expected an squared relation ships because as the diameter increases with a factor, the country would increase with 4 times that factor, so less beta atoms would be stopped by the shielding. If I had more clip to look into this I would take more readings and analyze the relationship.

The best puncture size is 5mm, it has the smallest angle which the beta atoms scatter through and the count is sufficient to utilize in my concluding experiment.

Measuring the Deflection of Beta Particles.

Diagram

Equipment

Strontium 90 beta beginning

Shielding

2 electric home bases

EHT

overseas telegrams

GM tubing and counter

Method

1. Put up equipment as in the diagram

2. Make certain that all the equipment is in line

3. Put the home bases at 5cm apart, utilizing the set square doing certain that the

home bases are 2.5 cm signifier the Centre line.

4. Turn on the EHT

5. Raise the electromotive force to 1kV

6. Use the 10 2nd count, move the GM tubing until there is a bead in the background count. Change to 100s and travel the GM somewhat until you merely acquire a back group count.

7. Record this consequence in the tabular array.

8. Repeat measure 5 to 7 increasing the electromotive force by 1kV

Consequences

Analysis

This experiment is similar to an negatron gun experiment I have done in the yesteryear. This experiment could be compared with a negatron gun, it has the same rules. For illustration ; Electrons are being released from the beginning and being deflected by the electric field. The differences are that this experiment was non carried out in a low vacuity, the beta atoms are being decelerated, due to impacts with air molecules.

V = velocity of an negatron,

E = Electric field strength,

vitamin E = charge of an negatron,

Vp = p.d. between the 2 home bases,

vitamin D = home base spacing,

m = mass of negatron,

ten = horizontal distance from point of entry,

Y = perpendicular supplanting from point of entry ) .

An negatron through a unvarying electric field experiences a changeless force.

F= eE = eVp/d

vitamin E = Fd/Vp

Work done = eVp

Fd = Vp

Each negatron produced form the beginning is attracted to the positive home base.

a = F/m = eVp/md

The perpendicular gesture of the negatron is non affected by gravitation, and the perpendicular gesture is non affected by the electric field.

Time taken for an negatron to go Y

T = x/v

giving y displacement s = ut + 1/2at2

The initial velocity is zero because the negatron has merely entered the electric field for y supplanting.

Y = 1/2at2 = 1/2 ( eVp/md ) t2

since a = eVp/md

giving Y = 1/2 ( eVp/md ) x2/v2

hence y = ( eVp/2mdv2 ) x2

Y = kx2 k = invariable

This equation is similar to the projectile equation.

Y = 1.2gt2

ten = Greenwich Mean Time

Y = ( g/2u2 ) x2

This is because that both atoms are under a changeless force playing in one way. g is the invariable for the missile and eVp/d for the negatron in the electric field.

The Y velocity is Vy = at because initial Uy = 0 because it has merely entered the electric filed.

Vy = at = ( eVp/md ) T = eVpx/mdv

The way of the beam is given by

TanA = Vy/Vx

Besides

Y = 1/2 ( eVp/md ) x2/v2

2y/x = ( eVp/md ) x/v2

Vy/v = 2y/x = eVpx/mdv2

When the negatron leaves the field, it appears to arise from the Centre of the electric field.

So 5 = ( vx2 + Vy2 ) 1/2

Mistakes in the probe.

The undermentioned mistakes occurred in this probe:

Measuring the electromotive force on the EHT.

x 10 Vs

The mistake values are:

Mistakes in mensurating the distance:

I used calipers to mensurate the distance that the beta atoms were deflected.

The distance measured was accurate to x0.05cm

The mistakes in numeration of radiation.

The mistake in mensurating readings form a random beginning, is determined by taking the per centum mistake as:

( ( timebase ) 1/2/ timebase ) x100

So the mistake of the 10 2nd counts are 31.6 %

100 2nd counts are 10 %

To accurately mensurate the distance that the beta atoms deflect, I used a 10 2nd count to obtain a unsmooth estimation the extent of the stake atoms and so used a 100 2nd count to utilize to happen accurate reading of were the all in atoms can t be detected.

Decision

I conclude from this probe that altering the electromotive force does alter the warp of the beta atoms.

I expected this because as a charged atom moves through a electric field, the atom is attracted to the oppositly charged home base. The greater pd.. between the home bases increases the attractive force, this is because the possible gradient is increased and the atom would go over more equipotential lines.

The lines of force have a great force moving between the home bases when there is a high palladium. This will hold a larger force moving on the charged atom. F = mom. Since the mass stays the same and the force is additions, so the acceleration must increase. The increased acceleration will do a greater supplanting over unit clip at higher palladium than a lower palladium.

The graph shows that there is a relationship V + D2, this gives a relationship similar to

Y = ( eVp/2mdv2 ) x2

Y = supplanting of the beta atoms

Vp = The palladium

vitamin E = charge on 1 negatron ( 1.6 & # 215 ; 10-19 ) }

m = The mass of an negatron ( 9.11 & # 215 ; 10-31 ) }

V = The velocity of the beta atom } Constant

ten = The distance that the beta atom travels through the field. }

If I re-arrange the equation to equal V:

V = + ( eVpx2/2mdy )

The values of V, from the information from the probe.

Since the speeds of the beta atom is changeless for this beginning because the energy released for each radioactive atom is approximately equal, Then each beta atom would hold a similar velocity. So I suspect that the values above have mistakes in the experiment.

I suspect that the mistakes are the undermentioned:

The beta atoms being scattered in the air, the atoms would clash with molecules in the air and would be deflected and would distribute out during and after the electric field. The screening would non bring forth a tight beam of beta atoms, the atoms would distribute out. This means that atoms that were non going analogue to the electric home bases would be deflected more and would look to give a warp value at 0 palladium. This would alter the deliberate value for the velocity, because as y supplanting increases the velocity decreases. The atoms would non look to arise from the Centre as in my analysis.

Evaluation

If I were to reiterate this probe, I would make the followers:

I would utilize my clip efficaciously, i.e.. non to pass more clip on the preliminary work than the existent probe. Even though that the preliminary work provided allot of information to utilize.

I would wish to look into the consequence that a magnetic field has on a beta atom. If I use the shielding I have at the minute would supply some new jobs in observing the beta atoms. The sprinkling would be difficult to mensurate, because the magnetic spirals do non incorporate the beta atoms like the electric home bases. I would hold to utilize a different sensor set-up.

The sensor I would wish to utilize, if I had more resources available, would be a radioactive sensitive movie, because I would see the overall warp of atoms from the experiment and see repulsive force force from the negative home base. Besides I would be able to mensurate the distance and ant the warp more accurately.