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TAS workshop 30-31/3/2004
Aspects of recoil-ion - correlations in atomic traps
• A reminder why (V-A , ?S + ?T)
• Energy scales basic setup RIMS
• Precision what to watch out for (LBL).+ versus -
• RIMS issues
• Preliminary setup
TAS workshop 30-31/3/2004
Motivation
Standard Model decay
dud
duu
:pnpn
:pnpp
πi
A J, Z πf
A J, 1Z
neutrino
electron
W±
V - A (V + S) – (A + T)If not SM
Measure - correlations
TAS workshop 30-31/3/2004
Correlations in -decay
• R and D test both TRV• D most potential • R scalar and tensor (EDM, a)• Learn the trade with “a”: ignore spin degrees of freedom
V0 (keV)
Principle idea MOT + RIMS
MeV
detector
MCP-V0 +V00
SM
Not SM
TOF E// very efficient
X,Y E for charged recoils
startstop
TAS workshop 30-31/3/2004
Learn from other experiments
• TRIUMF: 38Km(0+ 0+) aF=0.992(8)(5)promised:?(3)(3)
• LBL: 21Na (3+/2 3+/2) a= 0.524±0.005syst
• systematic error:1. RIMS related 41%2. Unwanted decays (off walls etc.) 26%3. Beta detection 24%
“work on RIMS”
TAS workshop 30-31/3/2004
+ versus - + decay recoil neutral (80%)
21Na (11p + 10n) 21Ne (10p + 11n) + +
80%
19%
3%
0.3%
- decay recoil 1+ : 80% no good case (?) 25Na (11p + 14n) 25Mg (12p + 13n) + -
•Neutrals not efficient•MCP inefficient and tricky+ momentum q-dist•2 background (511 keV)
TAS workshop 30-31/3/2004
RIMS scaled to -decay• Atomic physics
– recoil eV-meV fields V/cm
-decay– recoil 0.1 keV fields kV/cm -energy >> keV
MeVMCP
-V +V0 start
stopTOF E//
TOF + r E
TOF OriginAffects “a” strongly
z
r
-V
recoil
d a
qVE
d
EqVE
aMfE
//////
//
2)(TOF
TAS workshop 30-31/3/2004
Time scales and accuracy
qVEdar
a
a
da
da
qVaEqVMfeVE
daqVMfE
qVE
d
EqVE
aMfE
/)2(
24
2
TOF
TOF
/2/)200(TOF
2/)0(TOF
2)(TOF
//
//////
//
Resolution 1ns2a = 10 cmqV 5 kV 1 eVRange > 400 ns (q=1)Dynamic range > 4 sr < 4 cm
Time focus d=2a
Position focus?Pileup?……….??
Two realizations
Setup at TRIUMF (Behr et al.) for 38mK (t1/2=0.93 s; 0+ 0+)21Na production
Cooling stage
Trapping & detection
Freedman/Vetter setup LBL 21 Na
TAS workshop 30-31/3/2004
Conclusions
• Would have preferred - emitter (background)• RIMS is the trickiest part• Need TOF+2D readout MCP (+ multi hit)• Want 2D + energy of • Simulations needed (position and time focus)• Separate production from trapping (background)• Start working …..