# Magnitude of the (perpendicular) magnetic field in the separator?

• eric914
The radius of the path is not given, but it is proportional to the momentum, which is proportional to the velocity. So the radius increases by a factor of 5. During the second half of the motion the particle spends the same amount of time in the field, but the velocity is higher. Therefore it moves farther in the same time and the distance it moves is proportional to the velocity. So the time does not change.
eric914
ok so I'm working on a few problems on my physics homework and I got stuck:

On the first one I answered the first question, but I don't know how to approach the 2nd and 3rd parts... what formulas would i use? and on the 2nd questions, I thought i needed more information than just the time, I thought i need like velocity of something is there a way to do the problem without velocity?

1)A certain commercial mass spectrometer is used to separate uranium ions of mass 3.92 10-25 kg and charge 3.20 10-19 C from related species. The ions are accelerated through a potential difference of 50 kV and then pass into a uniform magnetic field, where they are bent in a path of radius 0.70 m. After traveling through 180° and passing through a slit of width 1.00 mm and height 1.00 cm, they are collected in a cup.

(a) What is the magnitude of the (perpendicular) magnetic field in the separator?
.5 T
(b) If the machine is used to separate out 130 mg of material per hour, calculate the current of the desired ions in the machine.
?? A
(c) In that case, calculate the thermal energy produced in the cup in 1.00 h.
?? J

2)In the figure below, a charged particle moves into a region of uniform magnetic field , goes through half a circle, and then exits that region. The particle is either a proton or an electron (you must decide which). It spends 90 ns in the region.
The image is a blue horseshoe shaped line entering the surface from the top on the right side and leaving the same way on the left, the magnetic field is pointed in ----> direction
(a) What is the magnitude of ?
?? T
(b) If the particle is sent back through the magnetic field (along the same initial path) but with 5.00 times its previous kinetic energy, how much time does it spend in the field during this trip?
?? ns

Thank you so much,
Eric

eric914 said:
ok so I'm working on a few problems on my physics homework and I got stuck:

On the first one I answered the first question, but I don't know how to approach the 2nd and 3rd parts... what formulas would i use? and on the 2nd questions, I thought i needed more information than just the time, I thought i need like velocity of something is there a way to do the problem without velocity?

1)A certain commercial mass spectrometer is used to separate uranium ions of mass 3.92 10-25 kg and charge 3.20 10-19 C from related species. The ions are accelerated through a potential difference of 50 kV and then pass into a uniform magnetic field, where they are bent in a path of radius 0.70 m. After traveling through 180° and passing through a slit of width 1.00 mm and height 1.00 cm, they are collected in a cup.

(a) What is the magnitude of the (perpendicular) magnetic field in the separator?
.5 T
(b) If the machine is used to separate out 130 mg of material per hour, calculate the current of the desired ions in the machine.
?? A
I assume the 130 mg is the mass of desired material that enters the cup, and that you only care about the portion of the current related to these ions. Otherwise you would need to know things you have not been told. You do need to know the charge to mass ratio; I assume the ions are singly charged.
(c) In that case, calculate the thermal energy produced in the cup in 1.00 h.
Assume inelastic collisions in the cup. All kinetic energy is converted to heat.
?? J

2)In the figure below, a charged particle moves into a region of uniform magnetic field , goes through half a circle, and then exits that region. The particle is either a proton or an electron (you must decide which). It spends 90 ns in the region.
The image is a blue horseshoe shaped line entering the surface from the top on the right side and leaving the same way on the left, the magnetic field is pointed in ----> direction
(a) What is the magnitude of ?
?? T
(b) If the particle is sent back through the magnetic field (along the same initial path) but with 5.00 times its previous kinetic energy, how much time does it spend in the field during this trip?
?? ns

Thank you so much,
Eric
See the annotations in the quote for #1.

I'm not seeing the pidture for the second one, but it must be a semicircular path for the particle in the field. If the field stays the same and the velocity increases by a factor of 5, the force increases, but the momentum was greater to bgin with. Find the magnitude of the force and consider the centripetal motion.

Last edited:

## 1. What is the significance of the magnitude of the perpendicular magnetic field in a separator?

The magnitude of the perpendicular magnetic field in a separator is important because it determines the strength of the magnetic forces acting on charged particles. This helps to control and manipulate the motion of these particles, which is crucial in various scientific and technological applications such as particle accelerators and plasma confinement devices.

## 2. How is the magnitude of the perpendicular magnetic field measured in a separator?

The magnitude of the perpendicular magnetic field in a separator can be measured using a variety of instruments such as Hall probes, magnetometers, and Faraday cups. These instruments can detect and measure the strength of the magnetic field at different points in the separator.

## 3. What factors affect the magnitude of the perpendicular magnetic field in a separator?

The magnitude of the perpendicular magnetic field in a separator is influenced by factors such as the strength and orientation of the external magnetic field, the design and materials of the separator, and the properties of the particles being separated. Additionally, any disturbances or fluctuations in the magnetic field can also impact its magnitude.

## 4. How does the magnitude of the perpendicular magnetic field affect the separation process in a separator?

The magnitude of the perpendicular magnetic field plays a crucial role in the effectiveness of the separation process in a separator. A stronger magnetic field will exert a greater force on the charged particles, enabling better separation and purification. However, if the magnetic field is too strong, it can cause undesirable effects such as particle loss and overheating of the separator.

## 5. Can the magnitude of the perpendicular magnetic field in a separator be controlled or adjusted?

Yes, the magnitude of the perpendicular magnetic field in a separator can be controlled and adjusted by changing the strength and orientation of the external magnetic field, as well as by altering the design and materials of the separator. This allows for flexibility in the separation process and enables scientists to optimize the performance of the separator for different applications.

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