Atoms & Nuclei

This item is designed to demonstrate the stabilizing effect of neutrons on the atomic nucleus. The ""protons"" are made of disc magnets while the ""neutrons"" are made of browned iron discs. The ""protons"" will, because they are magnetized, repel one another when placed on flat surface or overhead projector. The stabilizing effect of the ""neutrons"" is illustrated by placing them between the ""protons"", thereby eliminating the repulsive force. The ""protons"" are supplied with red marking, the ""neutrons"" with blue. Supplied as single pieces. The “neutron” can be ordered under product code MO150905.

This item is designed to demonstrate the stabilizing effect of neutrons on the atomic nucleus. The ""protons"" are made of disc magnets while the ""neutrons"" are made of browned iron discs. The ""protons"" will, because they are magnetized, repel one another when placed on flat surface or overhead projector. The stabilizing effect of the ""neutrons"" is illustrated by placing them between the ""protons"", thereby eliminating the repulsive force. The ""protons"" are supplied with red marking, the ""neutrons"" with blue. Supplied as single pieces. The “proton” can be ordered under product code MO150900.

Chain Reaction Apparatus, spare pins only.

Custom designed tongs for handling the radioactive sources RA95622 RA95626. Stainless steel construction. Dimensions (W x L): 12 x 165 mm.

Interface lead to link GM counter RA67530 to PC or laptop.

The Alpha particle Spark Detector from Frederiksen has been developed to enable visualization of alpha particles. The apparatus can be likened to a GM tube, but using atmospheric air instead of the diluted quenching gas in the tube. When alpha particles ionize the air in the spark gap of the detector, bright sparks can be both seen and heard. The apparatus incorporates a transparent lid, which allows clear observation of the sparks. The detector requires connection to safe high voltage (EHT) power supply with voltage range of 0-5 kV or 0-6 kV. The apparatus can be safely used directly on bench top or table and includes a removable threaded steel rod for mounting the unit on a radioactivity bench (RA95610) or squat retort base with thumbscrew (ST96274). • Gives clearly visible and audible response to alpha radiation • Demonstrates the ionization of air by alpha particles • Detects alpha radiation from radioactive minerals or radioactive sources • Allows study of range in air shielding by different materials

This GM counter is the most versatile and easily operated model yet. The counting time can be set to 1, 10, 60 or 100 seconds or set to manual start/stop. Counting may be set to run repeatedly and the last, complete result is displayed in the main display while new counts accumulate in the auxiliary display. The counter accepts both BNC and Jack type GM tubes. With the optional USB connection it can interface with computer and if pulse output for further hardware processing is required, that is also available. For demonstration purposes the authentic clicking Geiger-counter sound may be turned on if preferred. Other improvements over the previous model include lower overall system dead time and lower current consumption, with the unit now being powered by AA batteries. The counter may also be powered from the optional mains adapter.

Geiger-Muller Counter, Mains Adapter for RA67530.

A multipurpose GM tube, sensitive to alpha, beta and gamma radiation. Mounted in housing with protective cover and 10 mm diameter support rod. It is complete with integral lead and BNC connector. This GM tube does NOT have built-in anode resistor, and therefore requires counter with built-in anode resistor. Suitable for use with RA67530. • Window diameter: 9.14 mm • Recommended bias voltage: 500 V • BNC plug

This pack of 500 x 10 mm plastic cubes is used to investigate and demonstrate half-life. Each cube has one black face, the other faces all being yellow. The cubes are thrown or scattered like dice and those which land with the black face uppermost represent radioactive nuclei which have decayed. The black upward facing cubes are then removed, the remaining cubes thrown again and the process repeated. The removed cubes represent radioactive decay and decay curve can be plotted from the results.

This extra sensitive GM-tube has a large window which makes the detector well suited for measuring low activity sources. This provides more counts and thus improves counting statistics for more accurate determinations of half-lives, etc. The GM-tube housing is supplied with a protective cover as well as a protective grid in front of the window. It is sensitive to alpha, beta and gamma radiation. It is complete with a removable protective cap, holder, and integral lead with BNC plug. This GM tube does NOT have built-in anode resistor, and therefore requires counter with built-in anode resistor. Suitable for use with RA67530. • Useful diameter: 28.6 mm • Recommended supply voltage: 500 V • BNC plug

Fitted with a 10 mm diameter mounting rod, so the GM-tube may be held safely in the squat retort base.

A low cost apparatus for the demonstration of Rutherford scattering by means of gravitational analog of inverse square law repulsion. Comprises wooden launching ramp with guiding groove running down its curved front face along its length and index marks at 40, 60, 80 and 100 mm height above the base, that provides pre-determined launching heights. Also included is spun aluminium hill along with 19mm diameter steel ball. The shape of the aluminium hill has been carefully determined by varying its height above the base line by an amount arrived on the basis of the reciprocal of the radius. Ramp Dimensions (L x W x H): 300 x 50 x 105 mm. Hill Dimensions (Dia. x H): 280 x 60mm.

An instrument useful in showing the random nature of radiation, it produces spectacular bright sparks when alpha particles are ionised between the electrically charged circular wire grid and steel electrode. It comes complete with a sliding holder for an alpha radiation source, an accurate scale to measure the effects of distance between the source and the grid and is built in vacuum formed black plastic case. All of the electrical connections from an EHT power supply are through 4 mm insulated sockets. Connections to Timer Scaler and Frequency Meter are via BNC to BNC cable. Requires 5kV EHT power supply and alpha radiation source. Weight: 400g. Dimensions: (L x W x H) 310 x 77 x 85 mm.

A bench for radioactive sources and GM-tubes, providing stable and convenient setup, allowing reproducible results when making experiments with radioactivity. Investigate how the radioactive radiation spreads from the source in both angle and distance or investigate how radiation is absorbed by lead and aluminium. The bench is 60 cm in length, with a millimetre scale. Two riders are included, one for carrying a GM-tube, and the other for carrying the source holder*. The source holder can be fitted with a 6 mm diameter steel rod, for hanging absorber plates in front of the radioactive source. It can be rotated, and is fitted with degree scale ±110° - 1° • Lead plates: 5 x 2 mm thick, and 10 x 1 mm thick (enamelled to protect from lead contamination) • Aluminium plates: 6 x 2 mm thick, and 4 x 0.5 mm thick *Please note: This holder is only suitable for use with Frederiksen radioactive sources, which are available by special request only. The sealed radioactive sources can be used instead, with some limitations, using RA170800 source holder.

A multi-purpose instrument, combining the functions of a multi-purpose timer, ratemeter and frequency meter in one compact unit. It can be used as a simple stopwatch to more sophisticated applications such as dynamics experiments with air tracks etc. The scaler and ratemeter modes allow numerous radioactivity experiments to be undertaken. It has four, 7-segment LED digits 13 mm high. The high brightness and large size display make it ideal for classroom demonstrations. The microprocessor based design minimises the number of controls required and these are clearly labelled so that the instrument is very straightforward to use. The GM tube input is a TNC socket, TNC-to-BNC adaptor is required for connecting GM tube with BNC plug. Timer Four Auto Ranges: 0 to 9.999 s, 10 to 99.99 s, 100 to 999.9 s, 1000 to 9999 s Scaler Three Auto Ranges: 0 to 9.999 1000 counts, 10 to 99.99 1000 counts, 100 to 999.9 1000 counts Accuracy: ±0.01% Sensitivity: 160 mV peak Ratemeter Three Auto Ranges: 0 to 9.999 1000/s, 10 to 99.99 1000/s, 100 to 999.9 1000/s Frequency Meter Three Auto Ranges: 0 to 9.999 kHz, 10 to 99.99kHz, 100 to 999.9 kHz Max Input Signal: 20 rms Max Sensitivity: 250 mV rms Range: 10 Hz to MHz

The electron diffraction tube is highly evacuated tube with an electron gun consisting of pure tungsten heater filament and cylindrical anode all contained in clear glass bulb. The electrons emitted by the heated cathode are constrained to narrow beam by an aperture and are then focussed by means of an electron-optical system. The resulting tight, monochromatic beam then passes through micro-mesh nickel grating situated at the aperture of the gun. Onto this grid, thin layer of polycrystalline graphitised carbon has been deposited by vaporisation. This layer affects the electrons in the beam much like diffraction grating. The result of this diffraction is seen in the form of an image comprising two concentric rings that become visible on the fluorescent screen. spot resulting from the un-deflected electron beam continues to be visible at the centre of the rings. Also requires an EHT power supply. Specifications: • Max. filament voltage: 6.3 V AC • Max. anode voltage: 5 kV • Anode current: approx. 0.1 mA at 4 kV

The Fine Beam Tube is used for investigating the deflection of cathode rays in uniform magnetic field produced by pair of 300 mm Helmholtz coils. In addition, it can also be used for quantitative determination of the specific charge of an electron e/m. Located inside glass bulb with neon residual gas atmosphere is an electron gun, which consists of an indirectly heated oxide cathode, Wehnelt cylinder and perforated anode. The gas atoms are ionised along the path of the electrons and narrow, well-defined, luminescent beam is produced. Incorporated measurement marks facilitate parallax-free determination of the diameter of the circular path of the beam deflected in the magnetic field. The Fine Beam Tube is mounted on base with coloured connectors. In order to protect the tube, protective circuit is built into the base, which shuts off any voltage in excess of the base's pre-set cut-off voltage. The protective circuit prevents excessive voltages from damaging the heater filament and ensures ""smooth"" switch-on response once the voltage is applied. Requires 0-300 DC power supply and 300 mm Helmholtz coils. • Filament voltage: to 12 DC • Filament current: 300 to 450 mA • Anode voltage: 200 to 300 V • Anode current: 0.3 mA • Diameter of fine beam path: 20 to 120 mm • Division spacing: 20 mm • Tube diameter: 160 mm • Total height incl. base: 260 mm • Base plate: 115 115 35 mm • Weight: approx. 820 g

The Pair of Helmholtz coils is used for generating homogeneous magnetic field and for the determination of the specific charge of the electron e/m in conjunction with the dual-beam tube. The coils can be switched in parallel or in series. spring clip on the top crossbar is used to mount the Hall sensor during measurements of the magnetic field. The maximum field strength generated by the coils (~ mT) is approximately 750 times weaker than that produced by an MRI machine (~3 T), which are known to be safe for use by people with medical implants such as pacemakers. For use with RA130505. Requires 0-20 DC A power supply. • Coil Dimensions (Dia.): 300 mm • Coil spacing: 150 mm • Number of turns per coil: 124 • DC resistance: 1.2 ohms each • Maximum coil current: 5 A • Maximum coil voltage: 6 V • Maximum flux density at 5 A: 3.7 mT • Weight: 4.1 kg approx.

The dual beam tube can be used to determine the specific charge e/m from the diameter of the path followed by electrons fired into the tube from perpendicularly mounted gun with vertically aligned magnetic field and observation of the spiral path followed by electrons fired axially into coaxial magnetic field. The dual beam tube is partly evacuated electron tube, filled with helium at low pressure and equipped with both axial and perpendicular electron guns. The electron beams are perpendicular to one another and common deflector plate is provided for both guns. The electron beam source is an oxide cathode heated indirectly via heating coil. The electron paths show up as fine, slightly greenish beam due to impact excitation of the helium atoms. Requires 300 or 500 DC power supply. • Filament voltage: max. 7.5 AC/DC • Anode voltage: approx. 150 V DC • Max Anode current <30 mA • Deflector voltage: max. 50 V DC • Glass bulb: 130 mm dia. approx. • Total length: 260 mm approx.

For mounting all demonstration tubes and the optical equivalent. The tube holder consists of powder-coated cast aluminium with clamping fork made of heat resistant plastic and rotatable by 360°. The base plate contains two boreholes for mounting demonstration Helmholtz coils. Including an anti-skid support with three rubber feet. Weight: 1.5 kg. Supplied without tube. Dimensions 230 x 175 x 320 mm (L x W x H).

Pair of Helmholtz coils for generating a uniform magnetic field perpendicular to the axis of the Teltron D series tubes. Teltron Tube Holder D allows the coils to be configured in the Helmholtz geometry or to produce magnetic fields aligned vertically, or coaxial, with respect to the tube axis. The maximum field strength generated by the coils (~ 10 mT) is approximately 300 times weaker than that produced by an MRI machine (~ 3T), which are known to be safe for use by people with medical implants such as pacemakers. Specifications: Number of turns: 320 Max. continuous current: 1.0 A Max. momentary current: 10 min @ 1.5 A; 3 min @ 2 A Effective impedance: 6 Ω Max. field strength: approx. 10 mT Connectors: 4-mm sockets

For demonstrating the straight propagation of electron beams in field-free spaces by projecting the shadow of Maltese cross on fluorescent screen. Also intended for observing the focusing of electron beams by magnetic fields as an introduction to electron optics. The lower section of the maltese cross has hole 3 mm dia. which makes it possible to ascertain the orientation of the cross's shadow under the influence of magnetic fields. Specifications Max. filament voltage: 6.3 V AC Max. anode voltage: 5 kV Anode current: approx. 0.1 mA at 4 kV To perform experiments using the Maltese cross tube, the following equipment is also required: •1 Tube holder (RA67550) and •1 High voltage power supply 5 kV (115 V, 50/60 Hz) or 1 High voltage power supply 5 kV (230 V, 50/60 Hz) •1 Coil from Helmholtz pair of coils (RA67560) •1 DC Power Supply 20 V, 5 A (115 V, 50/60 Hz) or 1 DC Power Supply 20 V, 5 A (230 V, 50/60 Hz) •1 Bar magnet

Highly evacuated electron tube with focusing electron gun and fluorescent screen inclined relative to the beam axis, so that the path of the beam can be seen and the effects of electric and magnetic fields can be studied. The electron beam can be deflected electrically in the electric field of the built-in plate capacitor, and magnetically by using a Helmholtz coil pair D. By adjusting the electric field so that it cancels the magnetic deflection, it is possible to determine the specific charge e/m and the velocity of the electrons. Specifications: Filament voltage: 6.3 V AC Max. anode voltage: 5000 V Anode current: approx. 0.1 mA at 4000 V Max. capacitor voltage: 5000 V Fluorescent screen: approx. 90x60 mm² Glass bulb: approx. 130 mm dia. Total length: approx. 260 mm

For demonstrating the evidence of the particular nature of cathode rays, establishment of negative sign of charge, the ""electron"" as an atomic particle, concept of ""time-base"", operation of cathode ray oscilloscope, simple Lissajous' figures. The diode gun, tungsten wire ""hairpin"" filament and cylindrical collimating anode, projects narrow beam of cathode rays into the evacuated experimental zone. This beam traverses the sphere to impinge on the luminescent screen in spot about 4 mm in diameter. The narrow beam may be deflected in vertical plane to enter the Faraday cage by using Helmholtz Coils. further and horizontal deflection can be obtained using an Auxiliary Coil, thereby constructing simple cathode ray oscilloscope. All connections are made on the Universal Stand. Specifications Max. filament voltage: 6.3 V AC Max. anode voltage: 5 kV Max. capacitor voltage: 500 V Anode current: approx. 0.1 mA at 4 kV (anode)

Allows GM tube with BNC plug to connect to Scaler Timer Frequency Meter with TNC socket.

Aluminium discs each with different durable anodised finish-matt black, mirror black, matt silver and mirror silver. Bonded to the reverse of each disc is 30-650°C liquid crystal thermometer. These discs show in a clear and measurable way how absorption of heat radiation depends on surface colour and texture. The very low heat capacity gives quick results, meaning that many more experiments can be completed in each lesson. The discs can be used to investigate rates of cooling, the effects of filters and reflectors, inverse square law and equilibrium between absorption and emission. Supplied with a holder and storage box.

Gm Tube Test Source

The absorption plates have a hole in one corner for hanging from the source holder, and are supplied in a convenient storage box. •Lead plates: 5 x 2 mm thick and 10 x 1 mm thick (enamelled to protect from lead contamination. •Aluminium plates: 2 x 3 mm thick, 6 x 1 mm thick, and 4 x 0.5 mm thick.

This GM Tube & Holder has been designed to work directly with the IPC Timer Scaler & Frequency Meter but can also be used with any other suitable Scaler unit. The GM Tube contained within this stand-alone holder is the industry standard type: ZP1481, as recommended in the Cleapss document GL:138 (Choosing a Geiger Muller Tube). The ZP1481 has a large area detection window making it suitable for all practical demonstrations and investigations as well as having an efficiency level suitable for detecting alpha, beta and gamma radiation, it is also robust and has a long life. The holder containing the GM Tube not only provides both protection and a choice of connections to the Tube, but also the option to attach the holder to a retort stand using the supplied fixing rod. Also contained within the Holder is a high ohmic value (4M7) series resistor required by most Counter and Ratemeter (Scaler) units. If required the protection grill covering the detection window can be removed should you want to detect low levels of contamination. This model comes with a TNC plug.

This GM Tube & Holder has been designed to work directly with the IPC Timer Scaler & Frequency Meter but can also be used with any other suitable Scaler unit. The GM Tube contained within this stand-alone holder is the industry standard type: ZP1481, as recommended in the Cleapss document GL:138 (Choosing a Geiger Muller Tube). The ZP1481 has a large area detection window making it suitable for all practical demonstrations and investigations as well as having an efficiency level suitable for detecting alpha, beta and gamma radiation, it is also robust and has a long life. The holder containing the GM Tube not only provides both protection and a choice of connections to the Tube, but also the option to attach the holder to a retort stand using the supplied fixing rod. Also contained within the Holder is a high ohmic value (4M7) series resistor required by most Counter and Ratemeter (Scaler) units. If required the protection grill covering the detection window can be removed should you want to detect low levels of contamination. This model comes with a BNC plug.

Dry Ice Maker (Snowpack 30)

The Lascells Cloud Chamber is the perfect alternative to existing unreliable and time consuming dry ice variants. The chamber is self-contained and thermoelectrically cooled. The chamber requires no dry ice or water; the only setup necessary is the addition of isopropyl alcohol and connection to a mains socket. The chamber contains an integrated power supply and illumination of the chamber is provided by a high intensity LED. Using the provided source, tracks should be visible within 10 minutes. Once running the cloud chamber can be made to run for extended periods by adding more alcohol through the access provided in the lid.