The Geiger Muller Pancake LND 7317 tube is the best probe for the accurate detection of Alfa radioactivity, Beta e Gamma.
If you are a radioprotection expert, A researcher or simply a fan in the world of detecting ionizing radiation, You will surely have had a direct experience with the Geiger counter. This tool is essential to detect the presence of radioactivity in the environment and on objects of various kinds.
At the center of many of the more or less versatile and efficient geiger counters, there is a crucial component: il tubo Geiger. Among the various types available, il tubo Geiger Pancake It stands out for its unique characteristics and its exceptional sensitivity, in particular, the model LND 7317 It is a reference choice for many professional and amateur applications, see ours in this regard Geiger Made in Italy counters with pancake probe. which use this special high -performance probe as a sensor.
So in this article we will specifically deepen the functional and technical characteristics of the Pancake LND 7317 probe, exploring because this specific tube is so appreciated and what advantages offers in the detection of different types of ionizing radiation.
Operation of the Geiger tube: Fundamental principles
Before immersing us in the specificity of LND 7317, It is useful to understand how the Geiger tube works. Un Tubo Geiger-Müller (G.M.) It is the main sensor of a Geiger counter. It is essentially a sealed tube where in one of the extremes an anode consisting of a thread or plate that crosses it for most of its length and a cathode that in practice is the wall of the tube itself is inserted.
The Geiger tube is filled with a low pressure noble gas such as Neon or Argon, mixed with a small amount of halogen gases of “quenching”, which serves to extinguish as quickly as possible the discharge that is formed among the electrodes immersed in the same gas, When the tube is crossed by ionizing radiation.
When a particle of ionizing radiation (alfa, Beta O Gamma), Enter geige tube, Ionizes the atoms of its gas creating pairs of free ions and electrons that are accelerated in the path that goes from the cathode to the anode from the strong electric field produced by the high power supply voltage applied among the same electrodes as the Geiger tube.
This physical phenomenon causes a particular so -called effect: “Townsend avalanche”, which in practice is a real chain reaction, in which electrons collide with other atoms, creating further free electrons and therefore other ionizations.What make the internal gas for a short time at the Geiger tube. This produces a discreet electrical impulse that can be detected by a suitable electronic circuit inherent in the same Geiger counter.
In practice, the interaction of each particle with the gas internal to the Geiger tube, It produces an electric impulse in the Geiger counter that is translated into a “clic” sound and at the same time on the display display is also shown dose installments that is obtained by multiplying the number of impulses in the unit of time, For a particular conversion factor provided by the probe manufacturer himself.
Because the geiger tube "Pancake" It is better than conventional probes?
Il Tubo Geiger “Pancake” with the feature in the shape of a pancake and with a large active window in very thin not, It is an advanced variant of the traditional cylindrical geiger tube with the metal wall or borosilicate, Therefore, alpha radiation cannot be detected and to some extent it also attenuates the beta radiation not enough energy.
Its distinctive feature is the flat shape and circular in the shape of a pancake, In practice it allows you to maximize the area of the detection window made in very thin “mica”, while maintaining a minimum internal volume.
Precautions to be adopted in the manipulation of the Geiger Muller Pancake tube.
The pancake tube must be handled with maximum caution and delicacy, because unlike the ordinary geiger pipes that have the external metal or borosilicate coating, It has a large upper window made with a thin and fragile membrane in “mica”.
This material being very rigid is also particularly fragile, With particular industrial procedures it can be laminated in very thin sheets, until you reach minimum thicknesses of a few tenths of a millimeter.
The “mica” It is used to create the very thin membrane of the top window of the pancake, because its small thickness allows the “big” e “heavy” Alfa particles (consisting of helium nuclei), to be able to penetrate the same pancake without suffering appreciable attenuations.
The noble gas present in the Geiger tube can be ionized as well as by the beta and range particles also by these alpha particles with the consequent generation of an electrical impulse that will actively detect their presence.
Relevant characteristics of the G.M probe. Pancake:
Let's summarize what are the most important features of these particular Geiger Muller tubes.
Great sensitivity and precision Especially while measuring the ionizing radiation of limited activity and low energy, that the common probes with metal or borosilicate casing, they cannot in any case detect.
Large active survey area: The flat -fried frittella shape offers a significantly wider survey area than standard cylindrical pipes. This feature is essential for a faster examination of surfaces and greater efficiency in detecting any contamination.
Large window in thin Mica: I tubi Pancake, including LND 7317, typically use a very thin entrance window made of not. Mica is used for its small thickness and its low density, which allows particles with mass such as Alfa and low energy particles such as beta, to easily penetrate the tube and be detected as a consequence of internal ionization. The geiger pipes with window in no window can also detect from bass also the X -rays the beta radiation and low energy range.
Versatility in the detection: Thanks to the combination of a large area and a thin window, Pancake geiger pipes are considered “universal” in terms of detection, being capable of effectively detecting Alfa particles, Beta and Gamma/Rays X -rays X
Tubo Geiger Pancake LND 7317 - The detailed technical specifications
The LND 7317, It is a medium voltage geiger-müller tube with mica window, Built by the LND Company, Inc., An American company founded in 1964, specialized in the production of sensors for the detection of ionizing radiation. Their products are widely used in a vast variety of professional tools and portable devices for the detection of radioactivity.
Functional specifications and technical characteristics of the Pancake LND 7317 probe:
Filling gas: Neon + Aloogeno (Ne + halogen). The presence of a halogen gas acts as an agent of “quenching”, essential to quickly turn off each discharge and prepare the tube for the next detection, guaranteeing a longer duration than organic quinching gases.
Cathode realization material: Stainless steel
Higher window in Mica:
Areal density: 2.0 mg/cm². This extremely low density is essential to allow the penetration of low energy alpha and beta particles,
Actual diameter: 1.75 inches / 44.5 mm. This large actual detection area contributes to the high sensitivity of the tube.
Dimensions:
Maximum length: 3.00 inches / 76.1 mm.
Maximum diameter: 2.11 inches / 53.6 mm.
Actual depth: 0.5 inches / 12.7 mm.
Electrical specifications:
Registered operating voltage: 500 Volt. It is located in the center of the operating plateau or of the linear operating area, ensuring great stability and precision
Operating voltage interval: 475 – 675 Volt.
Maximum start -up voltage: 425 Volt.
Recommended anodic resistance: 4.7 Megaohm, with a minimum of 3.3 megaohm.
Slope of the maximum plateau: 10% per 100 volt. A low slope indicates greater stability of the tube to voltage variations.
Minimum dead: 40 microsecondi. Dead time is the period in which the tube is unable to detect new particles after an event, A low value is an indication of a better ability to manage high counting rates.
Gamma rays sensitivity (Co60 isotope): Circa 55-60 cps/mR/hr (counts second for Milliroentgen for now, o 3600 CPM/(mR/h) (~60 cps/mR/h). This parameter confirms the high sensitivity of the gamma radiation tube.
Tube capacity: 3 pF (picofarad).
Weight: 125 grams.
Operating temperature interval: da -40 a max +75 degrees Celsius.
The technical data confirm that the LND 7317 tube is a highly sensitive ionizing radiation detector, which can easily detect x rays, Gamma rays and alpha and beta particles.
For particles with not negligible mass such as Alfa and Beta particles (electrons), The subtle window in not proves to be fundamental for their detection.
Pancake LND 7317 geiger tube applications.
The Geiger Pancake LND 7317 tube is used in a wide range of sectors and applications:
Contamination monitoring: Is one of the probes used in Professional geiger counters for the verification of surface contamination in laboratories, hospitals, Industrial sites and in nuclear emergency environments.
Radioprotection and safety: Used by qualified experts of radioprothection to monitor exposure to ionizing radiation and guarantee safety in environments where there is the presence of radioactive materials.
Research and teaching: Employed in didactic experiments and research projects thanks to its versatility and ease of use.
Environmental detection: For monitoring the natural radiation fund and the search for radioactive sources in the environment.
Geology and prospecting: For the detection of radioactive minerals.
Robots for remote detection: It can be integrated into robotic surveys for monitoring contaminated or dangerous areas, thus reducing human exposure.
Limitazioni da Considerare per l'utilizzo del Tubo Pancake
Despite its numerous advantages, It is important to be aware of the few limitations of the Geiger tube:
Dead time: Like all GM pipes, There is a “dead time” After each detection, during which a new event cannot be detected. For Lnd 7317 it is about 40 microseconds. This limits the accuracy of very high counting rates in the proximity of very intense radioactive sources which in any case can be rarely found in a general use.
Lack of information on energy: In general, a geiger tube produces an impulse of equal width regardless of the energy of the accident radiation. This means that it cannot provide information on energy or specific type (alfa vs. beta) of the particle detected, but only their presence and the issue rate For energy discrimination, more complex detectors such as proportional counters or spectrometers with sparkling crystals are required.
Conclusion
The Geiger Pancake LND 7317 tube represents an excellent sensitivity combination, versatility and reliability in the field of radiation detection. Its wide window in a thin pulse and design “pancake” They make it particularly effective to detect a wide range of ionizing radiation, From low energy alpha particles to gamma rays. That you are monitoring contamination, leading research or simply exploring the world of radiation, LND 7317 is a pancake probe that offers high -level performance, making it a fundamental component for any serious enthusiast or professional in the sector.