College Physics Experiment 2009-02-26 18:59:30 Reading 17868 Comment 14 Font size: large, medium and small subscriptions.

University physics experiment report

Experimental topic: Frank Hertz experiment

Experimental equipment: F-H experimental tube, constant temperature heating electric furnace, F-H experimental device and oscilloscope.

Experimental content:

1. Be familiar with the experimental device and master the experimental conditions.

The experimental device consists of an F-H tube, a constant-temperature heating electric furnace and an F-H experimental device, and its device structure is shown in the following figure:

There is enough liquid mercury in the F-V tube to ensure that the mercury vapor in the tube is always saturated within the working temperature range. General temperature is 100? C to 250? C. And because Hg is highly sensitive to temperature, the temperature should be adjusted and not changed too much. Filament voltage controls the density and energy distribution of electrons emitted by cathode K, and its change directly affects the shape of the curve and the position of each peak, which is a key condition.

2. Measure the first excitation potential of Hg.

1) Start the thermostat controller, heat the ground F-H tube, and stabilize the furnace temperature at 157? C, and select the appropriate filament voltage, VG 1K=2.5V, VG2p= 1.5V, VF =1.3v. ..

2) change the value of VG2k and record it on the corresponding Ip value (record data every 0.2V).

3) Data processing, making corresponding Ip-VG2k diagram, and finding the first excitation potential of Hg (by differential method).

3. Measure the first excitation potential of Ar atom.

1) Adjust relevant data: Vp=8.36V, VG 1= 1.62V, VK2K = 0 ~ 100 V, VF = 2.64 V;

2) Adjust the relevant gear to the free gear to see whether the Ip-VG2k diagram obtained on the oscilloscope meets the experimental requirements (there are more than six peaks). Then adjust the relevant gear to manual gear.

3) manually change the value of VG2k and record it on the corresponding Ip value (record the data every 0.05V).

4) Data processing, making corresponding Ip-VG2k diagram, and finding the first excitation potential of Hg (by differential method).

4. Draw a conclusion.

Raw data:

1.VF = 1.3V VG 1K = 2.5V VG2p = 1.5V T = 157？ C

Data table for finding the first excitation potential of mercury atom