1. A GM pulse tube cold-head selected from one stage and two stage hybrid type cold heads comprising,
a pulse tube assembly attached to a warm housing,
the warm housing containing a first stage buffer volume and, in the case of a two stage pulse tube, a second stage buffer volume,
a valve motor assembly attached to the warm housing,
where the first stage buffer has a volume relative to the volume of the first stage pulse tube between 0.5 and 5.5 and the second stage buffer, in the case of a two stage pulse tube, has a volume relative to the volume of the second stage pulse tube between 0.2 and 3.5.
2. The pulse tube of claim one which is a two-stage pulse tube.
3. The pulse tube of claim 1 which has a hybrid type cold head and the first stage buffer has a volume relative to the volume of the first stage pulse tube between 0.5 and 3.5 and the second stage buffer, in the case of a two stage pulse tube, has a volume relative to the volume of the second stage pulse tube between 0.2 and 1.2.
4. The pulse tube of claim 3 where the first stage buffer has a volume relative to the volume of the first stage pulse tube of from about 1.75 to about 2.75 and the second stage buffer, in the case of a two stage pulse tube, has a volume relative to the volume of the second stage pulse tube of from about 0.5 to about 0.9.
5. The pulse tube of claim 3 where the first stage buffer has a volume relative to the volume of the first stage pulse tube of about 2.2 and the second stage buffer, in the case of a two stage pulse tube, has a volume relative to the volume of the second stage pulse tube of about 0.7.
6. The pulse tube of claim 1 in which the warm housing comprises a single piece.
7. The pulse tube of claim 1 in which the warm end housing comprises a first part and a valve housing.
8. The pulse tube of claim 7 in which one of the buffer volumes is in the first part of the warm housing and the other buffer volume is in the valve housing.
9. The pulse tube of claim 1 in which the axis of the valve motor assembly is at a right angle to the axis of the pulse tube assembly.
10. The pulse tube of claim 1 in which the axis of the valve motor assembly is in line with the axis of the pulse tube assembly.
11. The pulse tube of claim 1 which is a single stage pulse tube.
12. The pulse tube of claim 1 in which the warm housing comprises a single piece.
13. The pulse tube of claim 1 in which the warm end housing comprises a first part and a valve housing.
14. The pulse tube of claim 11 in which the axis of the valve motor assembly is at a right angle to the axis of the pulse tube assembly.
15. The pulse tube of claim 1 in which the axis of the valve motor assembly is in line with the axis of the pulse tube assembly.
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. Clock-pulse supply unit comprising:
a phase detector for comparing the chase of a first clock pulse with the phase of a second clock pulse;
a first receiver unit for receiving the first clock pulse and relaying the first clock pulse to the phase detector;
a second receiver unit which has the same parameters as the first receiver unit and serves to receive the second clock pulse and relay the second clock pulse to the chase detector;
an oscillator for generating the second clock pulse;
a transmitter unit connected between the oscillator and the second receiver unit in such a way that the second clock pulse generated in the oscillator is supplied to the second receiver unit via the transmitter unit; and
a changeover switch with one input and two outputs,
wherein the input of the changeover switch is connected to the output of the transmitter unit, and an output of the changeover switch is connected to an artificial line.
2. Clock-pulse supply unit according to claim 1, wherein the oscillator is a voltage-controlled oscillator whose control voltage is dependent on the output signal of the phase detector.
3. Clock-pulse supply unit comprising:
a phase detector for comparing the phase of a first clock pulse with the phase of a second clock pulse;
a first receiver unit for receiving the first clock pulse and relaying the first clock pulse to the phase detector;
a second receiver unit which has the same parameters as the first receiver unit and serves to receive the second clock pulse and relay the second clock pulse to the phase detector;
an oscillator for generating the second clock pulse;
a transmitter unit connected between the oscillator and the second receiver unit in such a way that the second clock pulse generated in the oscillator is supplied to the second receiver unit via the transmitter unit; and
a divider connected between the oscillator and the phase detector, wherein the divider and the second receiver unit have a control input for active and passive switching of the divider and the second receiver unit.
4. Clock-pulse supply unit according to claim 1, wherein the first and the second receiver unit have the same time delay.
5. Clock-pulse supply unit comprising:
a phase detector for comparing the phase of a first clock pulse with the phase of a second clock pulse;
a first receiver unit for receiving the first clock pulse and relaying the first clock pulse to the phase detector;
a second receiver unit which has the same parameters as the first receiver unit and serves to receive the second clock pulse and relay the second clock pulse to the phase detector; and
a reference clock-pulse changeover switch having an output connected to the output of the first receiver unit, wherein the reference clock-pulse changeover switch and the first receiver unit have a control input for active and passive switching of the reference clock-pulse changeover switch and the first receiver unit.
6. Clock-pulse supply unit according to claim 1, wherein the artificial line is suitable for simulation of a system clock-pulse bus.
7. Clock-pulse supply unit according to claim 1, wherein the first receiver unit is suitable for receiving a system clock pulse from a system clock-pulse bus, the changeover switch is suitable for switching the clock pulse received from the transmitter unit to the system clock-pulse bus, and the reference clock-pulse changeover switch is suitable for supplying to the phase detector at least one reference clock pulse, the frequency of which is lower than the frequency of the system clock pulse.
8. Clock-pulse supply unit according to claim 5, wherein the first receiver unit is suitable for receiving a system clock pulse from a system clock-pulse bus, the changeover switch is suitable for switching the clock pulse received from the transmitter unit to the system clock-pulse bus, and the reference clock-pulse changeover switch is suitable for supplying to the phase detector at least one reference clock pulse, the frequency of which is lower than the frequency of the system clock pulse.