[Isotope-prod] [EXTERNAL] Re: Experiment in the injector

[George Kharashvili]

Dear all,


One correction regarding the sample mass: our irradiated samples are ~61 g each.


Here is a brief summary of last year's tests and some reasoning for limiting beam power:

18.5 MeV
2.5 uA
1 hour
Produced ~0.1 uCi(microCi)
This beam was pretty close to our self-imposed power limit, so I doubt we can go higher in beam power, but we can increase Cu-67 yield by getting the sample closer to the radiator. I believe best we can do at this energy is something of the order of microCi in 2-3 hours of irradiation.

56 MeV
89.3 nA
5 minutes
We never managed to see actual Cu-67 in this test due to the overwhelming Ga-67 background, but we should've had ~22 pCi according to FLUKA. This test was limited to 110 W beam power from the point of view of the radiological safety (we compared everything to the radiological conditions of the spectrometer dump commissioning). Even if we lift the self-imposed 50 W limit by introducing better cooling, we can only produce around 10 uCi of Cu-67.

Just a reminder that there was nothing special about 56 MeV energy other than the 4D beamline was already set to this value.


Regarding requisites:

I agree with Pavel that we should be able to reuse the same samples.

18.5 MeV still sounds most inviting, as it is the highest energy at which we can comfortably do pre- and post-separation measurements.
Another energy point can be anything between 23 MeV and 30 MeV.

The reason why we did not have a precise measurement of beam energy is that when we broke the 4D line to make room for the irradiation, the harp ended up downstream of the samples. We should investigate what it would take to have the harp upstream of our setup, or may be install a beamviewer. So, depending on what beamline configuration we settle on, it may take some time to get there (last modification took several hours of work once access was granted).

Best regards,

George









Requisites: 


Do we have enough target material? (PD, GK) 


Do we have BNNT holders? (KJ) 





Beam parameters 





1. Beam Energy 18.5 MeV 


2. Beam current ? 


3. Beam time? 





Logistics 





Test plan ( revive the previous one, if we had one) 


Do we have the means to measure energy and beam size? (I will check) 


Assuming that VCU collaborators have time, how do we ship the 


irradiated sample? 





Anything else? 





Once our thoughts are organized, should we meet (even on the phone) 


for a few minutes to organize the experiment? 





Thanks. 





-H 






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