1. An ion trap for a mass spectrometer, the ion trap comprising:
a ring electrode configured to receive a radio frequency (RF) signal; and
first and second electrodes which are arranged on opposite sides of the ring electrode,
wherein the ring electrode and the first and second electrodes are configured to generate an electric field based on the received RF signal, and
wherein the first electrode defines a first aperture and the second electrode defines a second aperture, and wherein the first aperture and the second aperture are asymmetric relative to each other and configured to generate a hexapole field.
2. The ion trap of claim 1, wherein the first aperture and the second aperture have different diameters.
3. The ion trap of claim 2, wherein the second aperture has a diameter that is larger than a diameter of the first aperture.
4. The ion trap of claim 3, wherein the second aperture is sized to reduce ion deposition on a portion of the second end cap electrode surrounding the second aperture.
5. The ion trap of claim 1, wherein the ring electrode and the first and second electrodes are configured to generate a quadrupole electric field.
6. The ion trap of claim 1, wherein the first and second electrodes are flat electrodes.
7. The ion trap of claim 1, wherein the ring electrode and the first and second electrodes define a cylindrical configuration.
8. The ion trap of claim 1, wherein a maximum diameter the second aperture is determined based on a maximum desired hexapole field.
9. The ion trap of claim 1, wherein the dimensions of the second aperture relative to the first aperture are determined based on a desired hexapole field.
10. A mass spectrometer, comprising:
an ion trap configured to capture ions generated when a sample is ionized by an ion source, the ion trap comprising:
a ring electrode;
first and second end cap electrodes which are arranged on opposite sides of the ring electrode, wherein the first end cap electrode includes a first aperture, and the second end cap electrode includes a second aperture through which ions are discharged from the ion trap, wherein the first aperture and the second aperture have different diameters to induce a hexapole field component of an electric field inside the ion trap; and
an ion detector which detects an amount of the ions discharged from the ion trap.
11. The mass spectrometer of claim 10, wherein the ion trap is a three-dimensional ion trap.
12. The mass spectrometer of claim 10, wherein the ion trap is a cylindrical ion trap having an axially asymmetric configuration.
13. The mass spectrometer of claim 10, wherein the second aperture has a larger diameter than the first aperture.
14. The mass spectrometer of claim 10, wherein the first end cap electrode includes a first surface oriented towards the ion source, wherein the first surface includes a recess formed around the aperture, and wherein the recess and first aperture are configured to efficiently allow an electron beam to enter the ion trap.
15. The mass spectrometer of claim 14, wherein the second aperture has a diameter larger than the first aperture so as to prevent electrons from the electron beam from impinging an area of the second end cap electrode surrounding the second aperture.
16. The mass spectrometer of claim 10, wherein RF energy is applied to the ring electrode to generate the electric field in the ion trap, and wherein the dimensions of the first and second apertures are determined based on a desired electric field.
17. The mass spectrometer of claim 16, wherein a maximum diameter of the second aperture is determined based on a desired contribution of a hexapole field to the electric field.
18. A method of analyzing a sample, the method comprising:
ionizing a sample;
capturing the ions in an ion trap of a mass spectrometer, the ion trap comprising:
a ring electrode; and
first and second end cap electrodes which are arranged on opposite sides of the ring electrode, wherein the first end cap electrode includes a first aperture, and the second end cap electrode includes a second aperture through which ions are discharged from the ion trap, wherein the first aperture and the second aperture are asymmetric relative to each other to generate a hexapolar field component of an electric field inside the ion trap; and
detecting an amount of ions discharged from the ion trap.
19. The method of claim 18, wherein the electric field inside the ion trap is a quadrupole electric field.
20. The method of claim 18, further including causing ions to be ejected through the second aperture relative to the first aperture.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for cooling a passenger compartment in a hybrid vehicle that operates an engine intermittently during vehicle operation, the hybrid vehicle having an HVAC system including an HVAC duct, a blower adapted to direct a flow of air through the HVAC duct, an evaporator located within the HVAC duct, and a heater core, which has a coolant inlet and a coolant outlet and is located downstream of the evaporator in the HVAC duct, the method comprising the steps of:
a) cooling a refrigerant;
b) inducing a flow of said cooled refrigerant through said evaporator;
c) blocking a flow of coolant through at least one of said coolant inlet and said coolant outlet to thereby trap a predetermined amount of coolant in said heater core;
d) activating said blower to move air through said evaporator and heater core;
e) turning off the vehicle engine;
f) measuring a temperature indicative of a cooling function of said HVAC system;
g) starting the engine when the measured temperature is above a predetermined temperature; and
h) measuring an evaporator air outlet temperature;
i) measuring a heater core surface temperature;
j) blocking the flow of air through the heater core when the evaporator air outlet temperature is less than the heater core surface temperature and the vehicle engine is off; and
k) continuing the flow of air through the heater core when the evaporator air outlet temperature is not less than the heater core surface temperature and the vehicle engine is off.
2. The method according to claim 1 wherein step c) is performed when a predetermined air temperature has been reached in said HVAC duct.
3. The method according to claim 1 wherein step d) is further defined by actuating a damper in said HVAC duct to direct a flow of air through said heater core.
4. The method according to claim 3 wherein, prior to actuating said damper, the method includes a step of actuating another damper in said HVAC duct to provide only recirculated air to said HVAC duct.
5. The method according to claim 1 wherein step c) is further defined by actuating a valve in each of said coolant inlet and said coolant outlet to thereby trap the coolant in the heater core.
6. The method according to claim 1 wherein a controller receives and sends signals to perform steps a) through g).
7. The method according to claim 1 wherein, after step e), the method includes a step of actuating a damper in said HVAC duct to provide only recirculated air to said HVAC duct.
8. A method for cooling a passenger compartment in a vehicle that operates an HVAC compressor intermittently during vehicle operation, the vehicle having an HVAC system including an HVAC duct, a blower adapted to direct a flow of air through the HVAC duct, an evaporator located within the HVAC duct, and a heater core, which has a coolant inlet and a coolant outlet and is located downstream of the evaporator in the HVAC duct, the method comprising the steps of:
a) cooling a refrigerant;
b) inducing a flow of said cooled refrigerant through said evaporator;
c) blocking a flow of coolant through at least one of said coolant inlet and said coolant outlet to thereby trap a predetermined amount of coolant in said heater core;
d) activating said blower to move air through said evaporator and heater core and actuating a damper in said HVAC duct to direct the air through said heater core;
e) cycling said compressor off;
f) measuring a duct outlet temperature;
g) cycling said compressor an when the measured duct outlet temperature is above a predetermined; and
h) prior to actuating said damper, actuating another damper in said HVAC duct to provide only recirculated air to said HVAC duct.
9. The method according to claim 8 further including the steps of:
measuring an evaporator air outlet temperature;
measuring a heater core surface temperature;
blocking the flow of air through the heater core when the evaporator air outlet temperature is less than the heater core surface temperature a vehicle engine is off; and
continuing the flow of air through the heater core when the evaporator air outlet temperature is not less than the heater core surface temperature and the vehicle engine is off.
10. The method according to claim 8 wherein step d) is further defined by actuating a damper in said HVAC duct to direct a flow of air through said heater core.
11. A method for cooling a passenger compartment in a vehicle that operates an HVAC compressor intermittently during vehicle operation, the vehicle having an HVAC system including an HVAC duct, a blower adapted to direct a flow of air through the HVAC duct, an evaporator located within the HVAC duct, and a heater core, which has a coolant inlet and a coolant outlet and is located downstream of the evaporator in the HVAC duct, the method comprising the steps of:
cooling a refrigerant;
inducing a flow of said cooled refrigerant through said evaporator;
blocking a flow of coolant through at least one of said coolant inlet and said coolant outlet to thereby trap a predetermined amount of coolant in said heater core;
activating said blower to move air through said evaporator and heater core;
cycling said compressor off;
measuring a duct outlet temperature;
cycling said compressor on when the measured duct outlet temperature is above a predetermined temperature;
measuring an evaporator air outlet temperature;
measuring a heater core surface temperature;
blocking the flow of air through the heater core when the evaporator air outlet temperature is less than the heater core surface temperature and the compressor is off; and
continuing the flow of air through the heater core when the evaporator air outlet temperature is not less than the heater core surface temperature and the compressor is off.