ELECTRON ^IICKOSCOI'^ 



Fig. 5. Reflection image of martensite = 30°. 



Fig. 6. Reflection image of pearlite of drawn 

 high carbon steel d = 30°. 



its applications may be developed by attain- 

 ment to its higher resolution and by using 

 a specimen heating or gas reaction method. 



Specimen Cooling Method 



In electron microscope the specimen must 

 be irradiated by electron beams in the 

 vacuum. Therefore, in the ordinary method 



it is impossible to study the substance of 

 high vapor pressure, that of low melting 

 pohit or organic substances easily damaged 

 by electron irradiation. Cooling of the speci- 

 men to a large extent can prevent these ef- 

 fects and; develop the field of its applica- 

 tion. This is the best advantage in specimen 

 cooling methods. 



Construction and Performance of 

 Specimen-Cooling Device. The specimen 

 cooling device previously reported (5) had 

 many unsatisfactory points in its construc- 

 tion and was not suitable for obtaining high 

 resolution. A new specimen cooling device 

 has since been constructed (Figure 7) (6) 

 for JEM-5Y electron microscope. A is the 

 pouring port of refrigerant, B the refrigerant 

 reservoir with capacity of about 30 cc and 

 E the draught port. The refrigerant reser- 

 voir B, the pouring port A and the draught 

 port E are connected to each other by syl- 

 phon bellows C and D. The draught port E 

 makes it easy to pour the refrigerant into 

 the reservoir. The specimen holder F is at- 

 tached to the center of the round porcelain 

 H, which is set up to the specimen shifter 

 /. The temperature is measured by copper- 

 constantan thermocouple J fixed on the 

 specimen holder F. The heater K is used to 

 control the temperature of the specimen. 



To set up this device with JEM-5Y, the 

 refrigerant reservoir is kept at the position 

 shown by the dotted line, by rotating the 

 pinion A^ with the lever M. Then the whole 



P,S,T Q 



'Tffjfl 



t^^L^srr^ 



Fig. 7. Construction of new type specimen 

 cooling device. 



262 



