DE1179298B - High frequency powered spectral lamp with accessories - Google Patents

Description

UNDESREPUBLIC OF GERMANY

EUCHES

PATENT OFFICE

/ tfJSLEGESCHRIFT

Boarding school Kl .: HOIj

German class: 2If-82/01

Number: 1179 298

File number: V 21304 VIII c / 21 f

Filing date: September 14, 1961

Opening day: October 8, 1964

The invention relates to a high-frequency fed Spectral lamp with accessories that uses an electrode pse electric discharge lamp. In particular, the invention relates to a spectral arrangement which is opti-Icher during examinations polarized quantum states can be used in the context of iptic excitation. the “The requirements to be made in such an arrangement are that the radiation should affect one or narrow spectral range must be limited, ίο ! eringen is subject to fluctuations in intensity, shows practically no line reversal and as much as possible has loosely lying interference level.

For orders of the type discussed above, high-frequency feeds have already been used by the proprietor of the property rights Proposed spectral lamps that work with an alkali vapor discharge in such a way that Let the substance evolving alkali vapor is located in the reservoir space opposite the The cargo space is kept at a lower temperature.

There are already electrodeless gas discharge lamps brought to the surface by high-frequency fields known to use mercury vapor or alkali vapor for discharge.

A high-frequency powered spectral lamp with listening using an electrodeless discharge lamp, whose lamp bulb has a reservoir part in which there is a vapor for The substance developing the discharge is located and the reservoir space is at a lower temperature as the discharge space is held, is characterized according to the invention in that the The bulb of the discharge lamp is made of a material which, for the purpose of a certain heating has not inconsiderable high-frequency losses, Jind that for the inductive excitation of the high-frequency discharge one designed as a pair of flat coils and enclosing the lamp bulb on both sides Coil arrangement is provided and the reservoir space formed as a Seit-Hcher approach is in the ymmetrieplane extends downward between the flat coils.

A preferred embodiment of the invention provides that a generator arrangement for generating the high frequency is arranged adjacent to the lamp bulb and the discharge lamp is located in a closed room filled with air at atmospheric pressure to ensure that optimal thermal ambient conditions are ensured for the discharge lamp. The discharge lamp is expediently powered by a high-frequency spectral lamp
with accessories

Applicant:

Varian Associates, Palo Alto, Calif. (V. St. A.)

Representative:

Dr. phil. G. B. Hagen, patent attorney,

Munich-Solln, Frans-Hals-Str. 21

Named as inventor:
William Earl Bell, Palo Alto, Calif.,
Arnold Lapin Bloom, Menlo Park, Calif.
(V. St. A.)

Claimed priority:

V. St. ν. America September 16, 1960

(56 412)

Rubidium vapor operated, the discharge lamp containing krypton gas to facilitate starting.

It has proven to be useful that the two halves of the provided for excitation of the discharge Coil arrangement are wound in mirror image that the voltage-carrying end windings both halves are facing each other.

The above features and other usefulnesses of the subject matter of the invention result from the description and the figures. From the figures shows

1 shows a partially sectioned side view of an electrodeless discharge device according to the invention,

F i g. FIG. 2 shows a cross section corresponding to the section line 2-2 of the FIG. 1 shown device,

F i g. 3 is a schematic representation of the vibration generator which is used to operate the discharge device according to FIG. 1 supplies serving vibrations,

Fig. 4 is a schematic representation of the optical device, in> which the discharge device according to the invention is intended for use.

F i g. Figure 1 shows on a scale of approximately 2: 1 a spatially compact and light discharge

409 690/14 +

lamp that opposed to external thermal conditions and mechanical vibrations is secured and in particular serves the purpose with of high intensity to deliver radiation corresponding to the alkali metal vapor "D" line, whereby the Device is intended for use in a transportable and spatially compact optical examination device.

The discharge lamp 1 is inserted into an elastic silicone rubber spacer part 4 by means of a protruding reinforced wall part 2, which forms a small alkali metal vapor reservoir 3, the part 4 being placed on a plate S clad with copper, made of epoxy glass and forming a printed circuit. The discharge lamp is resiliently mounted in the divided coil arrangement 6, the coil arrangement being arranged on the plate 5. The discharge lamp 1 is located in a thermal protective vessel 7 which is filled with air at atmospheric pressure, the glass vessel 7 being cemented to the plate 5; a small crescent-shaped spacer body 8 made of silicone rubber is pressed between the vessel 7 and the discharge lamp 1. On the underside of the plate forming the circuit there is provided a self-regulating vibration generator which supplies a constant current and is shown in detail in FIG. 3 is described and consists of two miniature triodes 9, which are supplied from a terminal 11 with anode voltage; 12 is the terminal for supplying the heating current, and 13 is the grounding terminal, these terminals being attached to the aluminum cover 14. On the cover 14 there are two heating bodies which form a cylinder segment and are made of aluminum, to which two silver-plated brackets 16 are attached, which grip around the tubes 9 in a heat-conducting manner. An O-ring 17 made of silicone rubber is arranged on the upper side of the blocks 15 and forms a cushion for the plate 5 carrying the circuit 19 by the O-ring 20, which surrounds the cup-shaped vessel 7, elastically sealed.

The discharge vessel 1 has a diameter of approximately 1 cm and forms a small, intense light source, that can be sharply focused. The minimum frequency required to operate a discharge lamp this size is about 60 MHz. Higher frequency currents produce narrower emission lines and less intense disturbing radiation and also less hardening through metal atomization, which evidently results from the fact that the discharge particles have a smaller mean free path have per discharge cycle. The vibrator device shown in Fig. 3 is in its structure is very simple and efficient and generates little interference. The one that stimulates radiation Coil arrangement acts as a self-oscillating coil and is in turn in push-pull from the Amplifier triodes 9 excited, which lead through the crosswise from the anodes to the grid electrodes Capacities 30 are coupled together so that oscillations of approximately 100 MHz are maintained can be obtained.

Grid resistors 32 provide the negative bias voltage required to operate the tubes in C. A The anode circuit resistor 31 and a transverse capacitance 33 decouple the high-frequency oscillating circuit from the DC power source.

The two halves of the coil arrangement 6 used for excitation are mirror images in such a way that wound in opposite directions that the facing inner sides 35 of the coil halves the Lead high frequency, while the outer sides are high frequency "cold". When a discharge is initiated, there is a strong electric field between the end windings 35, whereby the ignition of the discharge is facilitated; after that the discharge through the high frequency magnetic field of the coil arrangement maintained, which in a uniform manner that in the immediate Discharge vessel 1 arranged in the vicinity is penetrated. By dividing the coil arrangement furthermore, the optical radiation is obstructed as little as possible.

The power supply arrangement is a constant current delivering, a high internal impedance having arrangement, so that the anode voltage and the corresponding output High frequency power is inversely proportional to the conductivity of the discharge lamp. Because the intensity of the discharge depends directly on the conductivity of the plasma, fluctuations in intensity will occur the discharge lamp is compensated by the fact that corresponding fluctuations in the opposite direction of the the service provided for the operation. In one model that was executed, the total power requirement was Including the power of the hot cathodes, about 6 watts.

The discharge lamp 1 consists of a material that has not inconsiderable electrical losses at the operating frequency of the discharge lamp. A material that is suitable for these purposes and also has the advantage. that it is easy to work with and is not attacked by the alkali metal and is also able to withstand considerable thermal shock loads, is a borosilicate glass, for example Pyrex 7740 glass, which is processed in a thickness of approximately 0.12 to 0.25 mm. The energy consumed by the discharge lamp is divided between the glass wall and the discharge, the penetration of the exciting field is limited by the conductivity of the discharge. Under these circumstances the atoms which cause spectral radiation are in the Near the wall of the discharge lamp, which is at a temperature suitable for the radiation through energy absorption is held in the glass wall: the phenomenon known as self-reversal the optical radiation in intervening cold atoms, which is a very narrow line of emission radiating atoms have the corresponding absorption line, becomes very small. The arrangement has furthermore a self-stabilizing influence with regard to the discharge, since a tendency of the discharge, to be less, is compensated by the fact that more high frequency energy in the discharge is consumed and thereby the conductivity decreases.

In order to make it easier to start an alkali vapor discharge, the filling gas is generally used Argon. The use of such a filling gas, however, often leads to a phenomenon in which the Discharge between the filling gas and the alkali

Claims (10)

5 6 Steam fluctuates back and forth, causing the cell 42 to penetrate considerably. Under the influence lent intensity fluctuations result. It has been directed most of the optical radiation showed that when krypton is used as filling atoms, it quickly changes to the non-absorbent state gas at a pressure of 1 to 3 Torr such unstable through a process that is sometimes called "optical Vibrations are completely avoided, which is called "pumps" and in which the absorbing anyway the ignition of the discharge is easily brought generating atoms into the excited P-state and in a reliable way spectral radiation in the loading and in the non-absorbing fine structure is achieved. It has also been shown that the fall state pass. When a high frequency current Use of the radioactive isotope Krypton 85 as of exactly the frequency of the separation of the underfill of the discharge lamp, the ignition voltages io levels of the coil 44, which the absorption cell 42 If what is possibly surrounding is reduced still further, then the occupation becomes the wishes is. A rubidium vapor spectral lamp, different sublevels of the atoms balanced, Contains 1 mg of rubidium mixed with a 2-Torr and there is a signal in the photocell 43 in krypton filling, was examined, and it was found, due to the increased absorption of the cell, a service life of at least 1000 hours at 15 This arrangement can be used in a magnetometer complete stability. The krypton filling is suitable find application in which the frequency of the a signal especially for use with rubidium, coil arrangement flowing through a signal whose isotopes are enriched. In general, however, it causes in the photocell which is responsible for the strength If you use discharge lamps with a natural external magnetic field, this is decisive. To a Rubidium, as such discharge lamps especially distort the magnetic field, which is measured The display in optical absorption cells should be prevented if possible, can be trio-suitable which are either enriched rubids made of titanium ceramic are used. In andium 85 or Rubidium 87, the considerations of the push-pull excitation circuit being the same Difficulty in producing enriched magnetic fields generated by the anode currents Rubidium, which generally only comes in the form of a 25, in the first order. To go even further Salt compound is available, is avoided. To suppress the distortion, the amplification The discharge lamp 1. is connected in a simple manner in tubulars via a long transmission line with constant thermal insulation by keeping an air volume at atmospheric pressure. This cell 42 enriched with rubidium-87 vapor is as effective as having a good vacuum fill and being in a microwave cavity with respect to maintaining the discharge at the proper level, with the filter 40 and polarizer being at the optimum temperature may be replaced for rubidium un- 41 through a filter cell which is dangerous at 130 ⁰ C, regardless of which Bedingun- enriched rubidium-85 vapor. Under conditions prevail in the room, and ensures that the 35 these circumstances results in a signal in the discharge to the discharge lamp itself limited photocell when the frequency of the oscillation supplied to the micro is approximately, even if in the outer space very low pressure wave cavity. The temperature of the metal reservoir 3 corresponds to 6834 MHz, which frequency is considered to be such that the most favorable vapor-over-fine structural transition is decisive. Since pressure in the discharge results, for example in case 40, this transition is independent of the outside of rubidium, the temperature is 100 ⁰ C, where the magnetic field is, the from the photocell 43 from this purpose, a heat flow can be used by conducted signal to the Fredie reservoir wall 2, the spacer body 3 and the frequency of a microwave generator to stabilize the base plate 5 results; The heat generated by the tubes 9 and thereby a normal frequency is radiated from the housing 18, 45 Since the spectral intensity of the discharge lamp 1, which a heat sink from a temperature of well within the absorption line of the cell 43 approaches 50 to 60 ⁰ C forms. Since the temperature of the is dissolved, so the optical radiation outside the reservoir is lower than that of the discharge zone, this line, which would represent an interference signal, there is no condensation of the vapor on the greatly reduced. It has already been discussed that there are only walls of the discharge lamp and not the very slight fluctuations in intensity of the migration of metal particles which interfere with the charge. Signal contributing radiation result. For this The optical display devices according to the invention have an arrangement of an optical investigation base using an extraordinarily high sensitivity discharge device according to the invention is shown in FIG. One positive and one low error number. With the discussed Anscher beam of a rubidium discharge lamp 1 through 55 order, magnetometer sensitivities are set by an interference filter 40, which _{suppresses the 7800-AD 2} - 0.01 γ and short-term frequency stabilities of line, while the 7948-λ-Dj line is down to 1 : 10 ¹² achievable, is transmitted, and furthermore a circularly polarizing polarizer 41 and an optical absorbent contains, whereupon the radiation on the photocell 43 1. High-frequency-fed spectral lamp with falls. The basic level of atoms in the cell 42 using an electrodeless accessory is generated by an external magnetic field in the discharge lamp, the bulb of which has a split up different magnetic sub-levels, reservoir part in which one is located the sub-level by a frequency of 65 Vapor for the discharge-evolving substance 4.66 Hz per gamma (γ- 1 10 ~ ⁵ gauss) are separated; and its reservoir space is on a low one of these basic levels does not absorb at a higher temperature than the discharge space. pull on the filtered and polarized light radiation, is characterized. that the bulb of the discharge lamp (1) consists of a material which for the purpose a certain heating has not inconsiderable high frequency losses that to inductive Excitation of the high-frequency discharge designed as a flat coil pair (6) and the Lamp bulb (1) on both sides enclosing coil arrangement is provided and that the as lateral approach formed reservoir space (3) in the plane of symmetry between the flat coils extends downwards. 2. Spectral lamp according to claim 1, characterized in that the lamp bulb made of borosilicate glass consists. 3. Spectral lamp according to claim 2, characterized in that the wall thickness of the lamp bulb is approximately 12 to 25 μm. 4. Spectral lamp according to claim 1 or one of the following, characterized in that heat dissipation means (5) are provided which receive a heat flow from the reservoir part 2, 3) of the discharge lamp (1). 5. Spectral lamp according to claim 1 or one of the following, characterized in that the Lamp bulb (1) has a diameter of about 1 cm and about 1 mg of rubidium and as Gas filling preferably contains krypton. 6. Spectral lamp according to claim 1 or one of the following, characterized in that the The lamp bulb (1) is adjacent to a generator arrangement (9) for generating the high-frequency energy is arranged and the discharge lamp (1) is in an enclosed space filled with air at atmospheric pressure. 7. Spectral lamp according to claim 6, characterized in that the vibration generator is a multivibrator with two triodes (9) and the anodes and grid electrodes of the same are capacitive (30) are mutually connected to each other. 8. Spectral lamp according to claim 7, characterized in that the high-frequency discharge stimulating coil arrangement (6) stimulated in push-pull by the multivibrator arrangement and acts as a resonant circuit coil. 9. Spectral lamp according to claim 8, characterized in that the two halves of the coil arrangement (6) are wound in mirror image so that the live end turns (35) both halves are facing each other. 10. Spectral lamp according to claim 6 or one of the following, characterized in that so heat conducting surfaces (16) are provided which dissipate the heat generated by the multivibrator arrangement (9) to the outside (18) of the housing. Considered publications: German patent specifications No. 477 311, 615 732,
435; U.S. Patent Nos. 1,854,912, 2,975,330;
Paperback for chemists and physicists by J. D'Ans and E. Lax, 1st edition 1943, Table 312, "Dielectric loss factor of some glasses", p. 1370. 1 sheet of drawings «9 690/1« 9.64 ι Bundesdnickcrei Berlin