2008年的Nature雜誌發表了一篇關於撕膠帶產生x-ray的論文。在接近真空的環境下，撕一捲3M膠帶居然能夠測量到x光的發射。這個現象被廣泛解釋為摩擦起電產生強大的電場，進而激發周圍的空氣放電及發光。然而長久以來尚未說明，為何僅透過摩擦就能讓膠帶產生如此強大的電場?我們猜測其來源與膠帶的黏膠在拉伸瞬間產生的細絲有關：細絲形成的過程侷限了電子的分佈範圍，絲愈細則該區就擁有愈大的局部電荷密度，因而不大的電荷數也可以在局部造成強電場。在這份論文裏，我們偵測不同速度下的撕膠帶電訊號，以及膠絲的粗細藉由高速攝影機搭配顯微鏡頭，來測量膠絲的動態與粗細；再搭配高敏感度的電荷偵測器，統計分析不同速度下電荷訊號的強度與數量之關係。我們發現隨著速度變快，絲會變得多而細，但超出某個速度範圍，絲便完全消失。電荷訊號數起初會隨速度的增加而變大，但是在某個臨界值之後，反而會下降。另外，還發現電荷量對速度的累積分佈呈現power law分佈。藉由兩者的統計性質，我們釐清電荷訊號與成絲的緊密關係。

In 2008, Nature published a thesis about X-ray emission of peeling tape. This
result surprised everyone that X-ray can be produced when peeling an adhesive
tape under environment near vacuum. This phenomenon was widely explained as
the electric field produced by triboelectrification that is large enough to excite the
surrounding air and caused the emission of light. However, it has never been clear
that why such large electric field can be produced only by triboelectrification. We
hypothesis that the origin of this field is related to the motion of tape filaments
during peeling. Filamentation process limits the region electrons can distribute.
The finer the filaments are, the larger the charge density each filament has. This
allows high electric field to exist even when charges produces by triboelectrifica-
tion are not much. In this thesis, we detect the charge signal and filament widths
at different peeling speed. Using sensitive charge detector and high speed cam-
era equipped with microscopic lens, we are able to analyze the relations between
intensity and quantity of different peeling speed. We found that as the peeling
speed grows, width of filaments will become finer and finer. However the filaments
disappear when speed exceed a certain threshold. Moreover, we have also found
that the cumulative distribution of charge amount and velocity is a power law dis-
tribution. By analyzing these relation, we are able to clarify the relation between
charge signal and filamentation process.

Introduction 1
2 Experimental setup and procedures 4
2.1 Filament detection .4
2.2 Charge detection .6
2.3 Light detection .8
3 Experimental results 9
3.1 Filament detection .9
3.2 Charge detection .11
3.3 Statistical analysis .14
4 Theory 18
4.1 Physical picture .18
4.2 Determination of tf .21
4.3 Determination of h0 + v⊥tf .23
4.4 Combine things together.24
5 Conclusion and discussions 27
5.1 Conclusion .27
5.2 Discussion .27
6 Appendix 29
6.1 signal discussion .29
6.2 Matlab code for signal processing of the charge detector .33
I
Bibliography 34
Bibliography .34

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