Fu Chun Yu Lab Notebooks

August 24, 1949. A search coil was made In studing the shillding effect of metallic to filing which were coated with SnO [?????????} by working with ver dilute HNo3

Measured the search coil in Q-meter

C1 reasonance freq.

30 mmt 25.5 MC 6. 18.5 MC 10 [-----?] of [enanieded?] wires of 5 mm dia.

L ( C+C1 ) = 1/4 tt 2 f2 L ( C + 30 ) = 3.9 x 10-5 L ( C + 60 ) = 7.4 x 10-5

C+60 7.4 = 1.9 C+ 30 3.9 = "

C + 60 = 1.9c+ 57 0.9c= 3 C=10/3= 3.33mmf L= 1.17 [???]

August 26, '49

Fine tin powder was made from CP tin by filing. Total amount = 7.5 gms in 3 cc. Density = 2.5 gms/cc

A search coil was immersed in this tin powder. No reduction of radio signal by comparison of the output with that by without tin powder. No shielding effect was observable.

Sample Sb #4

Dissolve 21 gms of SbCl₃ into 12 c.c of warm soln. Stand for a few days. Pour the 7 cc clear soln into a test tube & add two c.c of conc. HCl. The precipitate rejected. Contains min SbCl₃ 1 gm/c.c. ~ 5 Molar of Sb

August 27, 1949 Sb #5 15 gms of SbCl₃ in 3 cc. conc. HCl makes a 8 c.c. soln Molarity ~8 M

August 28, 1949 Size & Sign Comparison (Tin)

Sizes of resonance lines of Sn¹¹⁹, Sn¹¹⁷, Sn¹¹⁵ compared at the same frequences 7.14 MC

γ² (Sn¹¹⁹) : γ²(Sn¹¹⁷) : γ²(Sn¹¹⁵) = 1.096 : 1.00 : 0.843

Abundance Sn¹¹⁹ : Sn¹¹⁷ : Sn¹¹⁵ = 9.8 : 9.1 : 0.4

Product of abundance & γ² = 1.075 : 0.91 : 0.0337 = 1.00 : 0.846 : 0.0314 100 : 84.6 : 3.1

RMS (a) ------ empty tube induced netage = 0.012v To vaccum tube volhuster (b) -------- filed this filmigs, RMS induced voltage = 0.011v

(c) ---- coil surrounded by a small copper of about 0.2mm Hosh induced netage = 0 Conclusion Nethough the the zie of this filnig in large the shielding effect is very small Bloch: Perhaps the tin filing were over oxidized that we were working with the oxide rather than tin metal. Experiments must be repeated with tin metal. 8/26/49 repeated with metallic tin. No shielding effect.

August 30, '49

Block pointed out that, if γT₂ = T₁γ² = [const] as would be the case for termal broadening of the Sn isotopes, that our isotope identification would be backwards, since it turns out that

dv/dΔω h_max = -γ²([const.])T₂²

[Now it] T₂ = 1/γΔH and ΔH = kH, then T₂ = 1/γkH = 1/kΔω & since we compare at [const.] freq, T₂ = [const] [therefore] our γ² correction is correct on opposite page.

Test Sample #5 A (5075 [right arrow] 5050)

Comparison of resonances of [] tin isotopes at the same frequency

August 25, 1949.

Non-linearity in the Freq. Measurement

ν frequency

x line in recording milliammeter

Measure rate in units of KC/line (= dν/dx)

Assume the rate vary linearly (not uniformly) with frequency in an interval of 25 KC.

ν₀ = [?] freq.

ν₁ = final "

where a(ν₀ = rate at frequency ν₀

per line

Integration of (1) gives

Cd B (5925 --> 5900 KC)

Na (6375 --> 6350 KC)

8600 8575) B Width Dist Markey Res. Dist 5.2mm 79.3mm 6.5mm 4.0 (Markey 2) 3.8 4.0 v=8597.9 KC 3.8 Av=4.16 +- 0.57 Rate=25/79.3=0.316 KC/mm =4.16(1+-0.14)mm Width Ratio=4.16(1+-0.14)x0.316/3.07(1+-0.07)x0.222=1.93(1+-0.16) =1.93+-0.31 Freg Ratio=8597.9/5070.5=1.70 Width Ratio/Freg Ratio=1.14(1+-0.16) =1.14+-0.18

Selenium Search B xx 4/5 KG C 4.5 KG A 6/6 KG 10.5 KG 0.5 1.0 1.5 uN Sept 8 1949 Se Search v(H2) = 6.74 MC