ADOPTED LEVELS, GAMMAS for 242Cm

Authors: M.J. Martin, C.D. Nesaraja |  Citation: Nucl. Data Sheets 186, 261 (2022) |  Cutoff date: 31-Dec-2021 

 Full ENSDF file | Adopted Levels (PDF version) 


Q(β-)=-2950 keV SYS(n)= 6969.4 keV 12S(p)= 5419.6 keV 4Q(α)= 6215.63 keV 8
Reference: 2021WA16

References:
  A  242Am β- decay (16.01 H)  B  242Bk ε decay
  C  246Cf α decay  D  241Am(209Bi,208PBG)

General Comments:

For references on theory, refer to the NSR file at the Web site given in the abstract.

Q-value: ΔQ(β-)=140 (syst,2021Wa16)

Q-value: S(2n)=13063.2 17, S(2p)=9899.6 4 (2021Wa16)










E(level)
(keV)		XREFJπ(level) T1/2(level)E(γ)
(keV)		I(γ)M(γ)Final Levels
     0.0A CD 0+ 162.88 d 8 
% α = 100
% SF = 6.2×10-6 3
% 34Si = 1.0×10-14 +4-3
     
    42.13 5 A CD 2+      42.129 7 
  100
E2
     0.0
0+
   137 2 A CD 4+      96 3 
  100

    42.13
2+
   288 6 A CD 6+     150.2 5 
  100
[E2]
   137
4+
   489.1 13    D 8+     200.8 5 
  100

   288
6+
   735.9 14    D 10+     246.8 5 
  100

   489.1
8+
  1026.2 15    D 12+     290.3 5 
  100

   735.9
10+
  1355.2 15    D 14+     329.0 5 
  100

  1026.2
12+
  1720.8 16    D 16+     365.6 5 
  100

  1355.2
14+
  2119.5 17    D 18+     398.7 5 
  100

  1720.8
16+
   0+X     40 ps 15 
% SF = 100
     
  2549.3 18    D 20+     429.8 5 
  100

  2119.5
18+
     2.8E+3 4      180 ns 70 
% SF = ?
% IT = ?
     
  3008.8 18    D 22+     459.5 5 
  100

  2549.3
20+
  3497.4 19    D (24+)     488.6 5 ?
  100

  3008.8
22+
  4015.7 20 ?   D (26+)     518.3 5 ?
  100

  3497.4
(24+)

E(γ): From (209Bi,208Pbγ), except as noted

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Band Transitions:

E(level)
(keV)		Jπ(level) T1/2(level)E(γ)I(γ)M(γ)Final Levels
Band 1 - K=0 g.s. Band
     0.0 0+ 162.88 d 8 
% α = 100
% SF = 6.2×10-6 3
% 34Si = 1.0×10-14 +4-3
     
    42.13 5  2+      42.129 7 
  100
E2
     0.0
0+
   137 2  4+      96 3 
  100

    42.13
2+
   288 6  6+     150.2 5 
  100
[E2]
   137
4+
   489.1 13  8+     200.8 5 
  100

   288
6+
   735.9 14  10+     246.8 5 
  100

   489.1
8+
  1026.2 15  12+     290.3 5 
  100

   735.9
10+
  1355.2 15  14+     329.0 5 
  100

  1026.2
12+
  1720.8 16  16+     365.6 5 
  100

  1355.2
14+
  2119.5 17  18+     398.7 5 
  100

  1720.8
16+
  2549.3 18  20+        
  3008.8 18  22+     459.5 5 
  100

  2549.3
20+
  3497.4 19  (24+)        
  4015.7 20  (26+)     518.3 5 ?
  100

  3497.4
(24+)

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Additional Level Data and Comments:

E(level)Jπ(level)T1/2(level)Comments
     0.00+ 162.88 d 8 
% α = 100
% SF = 6.2×10-6 3
% 34Si = 1.0×10-14 +4-3
T1/2(SF)=7.0×106 y 2 is recommended by 2000Ho27 from measured partial half-lives of 7.2×106 y 2 (1951Ha87), 6.82×106 y 18 (1967Ar09, revised value; see 2000Ho27), 7.46×106 y 6 (1979Ch41), 7.15×106 y 15 (1982Ra33), 6.89×106 y 17 (1982UmZZ), 6.98×106 y 33 (1986Ze06; revised value; see 2000Ho27), 6.96×106 y 18 (1989Us04).
E(level): T1/2(SF)=7.0×106 y 2 is recommended by 2000Ho27 from measured partial half-lives of 7.2×106 y 2 (1951Ha87), 6.82×106 y 18 (1967Ar09, revised value; see 2000Ho27), 7.46×106 y 6 (1979Ch41), 7.15×106 y 15 (1982Ra33), 6.89×106 y 17 (1982UmZZ), 6.98×106 y 33 (1986Ze06; revised value; see 2000Ho27), 6.96×106 y 18 (1989Us04). K=0 g.s. Band.
    42.132+   E(level): K=0 g.s. Band.
   1374+   E(level): K=0 g.s. Band.
   2886+   E(level): K=0 g.s. Band.
   489.18+   E(level): K=0 g.s. Band.
   735.910+   E(level): K=0 g.s. Band.
  1026.212+   E(level): K=0 g.s. Band.
  1355.214+   E(level): K=0 g.s. Band.
  1720.816+   E(level): K=0 g.s. Band.
  2119.518+   E(level): K=0 g.s. Band.
   0+X 40 ps 15 
% SF = 100
Only SF decay observed. 100% SF branching is consistent with systematics of spontaneously fissioning isomer half-lives (see 1975Me28,1976Sl01).
E(level): Only SF decay observed. 100% SF branching is consistent with systematics of spontaneously fissioning isomer half-lives (see 1975Me28,1976Sl01).
  2549.320+   E(level): K=0 g.s. Band.
     2.8E+3 180 ns 70 
% SF = ?
% IT = ?
Assignment: 240Pu(α,2n) excit (1971Br39), 243Am(p,2n) E(p)=20 MeV (1971Re11).
E(level): Assignment: 240Pu(α,2n) excit (1971Br39), 243Am(p,2n) E(p)=20 MeV (1971Re11).
  3008.822+   E(level): K=0 g.s. Band.
  3497.4(24+)   E(level): K=0 g.s. Band.
  4015.7(26+)   E(level): K=0 g.s. Band.

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Additional Gamma Comments:

E(level)E(gamma)Comments
    42.13    42.129E(γ): from 242Am β- decay. Other: 42 3 from 246Cf α decay
M(γ): from conversion electron ratio in 242Am β- decay
   137    96E(γ): From 246Cf α Decay
   288   150.2E(γ): from (209Bi,208Pbγ). Other: 147 5 from 246Cf α decay

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