HEP Thin Films Biweekly

Tuesday 28 Apr 2026, 11:30 → 12:30 US/Pacific

Useful info:

• Google Drive: https://drive.google.com/drive/u/1/folders/0APSxdpDBE2RzUk9PVA
• Github space: https://github.com/hepthinfilms

 

Zoom link: https://ucsc.zoom.us/j/93578483281?pwd=KzNUK3FQOE5FNzZmbXB4V1U2ajUzdz09

11:30 → 11:40 Single-pad InP characterization paper update

Overleaf: https://www.overleaf.com/project/6916482c7c9af29611dcb701

Speakers: Earl Russell Tang Almazan (University of California,Santa Cruz (US)), Dr Jennifer Ott (University of California,Santa Cruz (US))

11:40 → 11:50 Argonne update

Speakers: Jessica Metcalfe (Argonne National Laboratory (US)), Sungjoon Kim

11:50 → 12:00 UHawaii update

Speaker: Dr Jennifer Ott (University of California,Santa Cruz (US))

Meeting minutes

 

Earl’s presentation: data analysis / fitting

• -        Persistent current phenomenon
• -        Arrhenius equation on linear fit of ln(current) over 1000/K: linear, now by excluding cluster of spread points, slope of two different devices matches closely, third also in general agreement but has fewer points
• -        Shiva: suggested to report current densities instead of raw values (for easier comparison and general idea of detector dark current behaviour)
• -        Sungjoon: one or several traps? – cf. modelling by Taylor et al, cf. plots of trap distributions later
• -        Jenni: experimental data would show effective / average ‘activation energy’
• -        Fit single or multiple exponential in persistent current
• -        ‘stretched’ fit

 

Richville’s slides:

• -        Recap of simulated device geometry
• -        Bias up to +- 500 V
• -        Target: implement temperature parameter to be varied
• -        Changed definition from AmbientTemp to variable, conversion from input Celsius to Kelvin
• -        First: temperature difference not implemented

o   Physics model is/was in material definition: only applied to given material -> instead added global physics section to set temperature

• -        First plot shown includes 0 and -15 C – lower current for lower temperature (as expected); somewhat high current with trap model ON
• -         Will continue running other temperatures (-15, 0, 15, 24.85, 30 C), then provide CSV data to Earl – through shared Drive
• -        Eventually specify one or a few given bias points, then simulate as function of temperature on x-axis
• -        Plot of energy bands / DOS over band gap, including trap level and tail states

o   Take out tail states..? Were taken from aSi simulation?

o   Assuming Gaussian for trap state – sigma/width can be defined in trap model

o   Delta function for trap DOS distribution? Need to check in documentation, we are aware so far of Gaussian and Exponential

• -        Trap level: Sungjoon to point to literature for trap level (and width..)?
• -        Start Geant4 simulation of 15 keV x-rays on same device geometry

 

ANL update cont. /Jessica

• -        thin films for detector R&D consortium discouraged (not surprising based on earlier statements with program manager)
• -      EFRC within BES base at ANL: not selected, but happy with the process – started reaching out to potential new collaborators, outside of HEP world
• -        Back to applying for internal funding
• -        No updates/change on CVD (need funds)
• -        ANL has monthly meetings with Helmut on detector R&D – not technically part of funded ANL portfolio, but Helmut has asked for update at next meeting: later in May. Might try to get integrated into FWP, but a lot of uncertainty in budgets.

12:00 → 12:10 RIL update

Speaker: Shiva Abbaszadeh

12:10 → 12:20 SCIPP update

Speakers: Earl Russell Tang Almazan (University of California,Santa Cruz (US)), Taylor Shin, Vitaliy Fadeyev (University of California,Santa Cruz (US))

InPDevice_3D_Simulation_Preliminary_Report.pdf

XRay2_Apr28.pdf

12:20 → 12:30 AOB